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Fresh Lime Juice: WTF?

October 1st, 2010 · Uncategorized

by Dave Arnold

When it comes to lime juice, freshest is best…right?  Not so fast!

At Tales of the Cocktail one of my co-speakers, Death and Co super-star bartender Thomas Waugh, and I got into an argument about lime juice. He insisted that juice made with a machine –specifically the Sunkist Juicer:

Sunkist commercial juicer: juicing at the speed of thought.

is inferior to juice pressed by hand using this:

Hand juicer: goes anywhere, is only as fast as its master.

When we finished bickering about  juicer merits I launched  into my standard anti-old-lime-juice tirade.  Lime juice doesn’t keep.  I have spent years and thousands of dollars trying to achieve good lime flavor that sticks around, but  neither I nor the corporations that have spent way, way more  have found a way to truly preserve fresh lime flavor.  I’ve tasted the best that the flavor houses can muster –which are good, but not perfect.

After the seminar, a bartender approached me and said his bar had run some  tests, the results of which showed that they preferred the taste of lime juice that was several hours old to fresher lime juice.  I wish I could remember who he was.  His conclusions struck me as odd, and this Wednesday I decided to investigate further.

The Test:

This week I was a guest speaker at the BAR program –the mega bartender class  by Dave Wondrich, Dale Degroff, Paul Pacult, Steve Olsen, et al.  I was to speak to 55 people who had just gone through a rigorous spirits tasting program.  I decided to do the lime juice test:

At 2pm we separated 1.5 cases of limes into 3 equal piles. I juiced 1 pile in the Sunkist juicer and 1 pile with the hand juicer.  We were done by 2:15.  We weighed the samples –the machine juicer yielded 26 ounces of juice, the hand juicer 21.5. I then put the juice in covered quart containers and left them out of the fridge.

The yield from the hand-juiced limes on the left, the Sunkist on the right.

At 6:15pm I juiced the third pile.  We then made limeade by mixing the same amount of each lime juice with measured amounts of water and simple syrup.  We served it in a blind tasting at 7pm.

Results:

The overwhelming favorite was the hand-squeezed lime juice that was 4 hours old. The distant second place was 4 hour old machine pressed juice.  Almost no one chose the fresh hand squeezed juice.  Before I revealed what the samples were, I asked those who chose the 4-hour hand-pressed juice to choose a second favorite.  They all chose the 4-hour machine juice. I was flabbergasted, and so was the audience.

The tasting panel.

If these results are repeatable, hand-pressing makes better juice than machine-pressing (in a Sunkist), but the effect isn’t as important as using slightly aged lime juice. Your drinks are probably tasting better at the end of your shift than at the beginning.

Age Your Juice? Some Comments:

I don’t know why the 4 hour juice tasted better.  Clearly we need to run more tests.  What is the optimum aging time? Don’t know yet. Maybe the bartender I met at Tales will step up, reveal his identity, and give us his results.

Some tasters commented that  that the aged juices not only tasted better, but had more of an acid bite.  If this is true,  making a well balanced pre-batched lime drink several hours before service will result in an unbalanced, overly acidic drink at service time.

Aged lime juice –while preferred in limeade, might not be the best for every drink application.  Perhaps a margarita is best with aged juice and a non-cordial gimlet is best with fresh –or vice versa. More tests.

Lastly, if indeed the aged juice tastes more acidic (and I don’t mean it actually has more acid –ie has a lower pH; these are just subjective taste impressions), maybe the fresh limeade would have won the taste test if we had added a couple extra ounces of it to the limeade.

The Sunkist Versus the Hand:

Why did the juice from the hand press beat out the Sunkist?  There are several possibilities:

1. The oil extraction from the peels could be different in the two techniques.

2. The juice that comes out of the lime first might taste better than what comes out last –so the increased yield of the Sunkist would compromise flavor.

3.  The spinning reamer of the Sunkist might be scraping some bitter stuff out of the pithy albedo.

Left: hand-juiced lime front and back; Right: machine juiced lime.

Yet more tests (sigh).

As a juicer (not a machine, but a person who juices)—I like using both techniques. They both have a Zen thing to them. I am a little depressed that the hand juicer won so overwhelmingly, because now I will never use the Sunkist unless yield or time is of utmost importance. Speaking of the time it takes to juice limes, most people are very slow using a hand juicer –two or three times slower than they are on a Sunkist.  A good hand-juice ninja can easily beat a novice Sunkist user. A master of the Sunkist, however, can produce a rain of spent lime halves reminiscent of the Matrix, and a torrent of juice like a waterfall.

Of course, I like to juice things.  I secretly believe that a person’s worth is roughly proportional to how fast they can juice 3 cases of citrus. Maybe I’ll write a post about it.

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Star Chiefs –The Cocktail Demo with Recipes

September 29th, 2010 · centrifuge, Chocolate, Clarification, cocktails, liquid nitrogen, Puffed Snack, rotovap, Tech Demo, Uncategorized, vacuum infusion

by Dave Arnold

At this year’s Star Chefs conference I whipped up some beaver-flapper puffs for the crowd to munch on (see here for recipe), and Nils and I liquored everyone up with a passel of cocktails.

A puffed whole beaver flapper.

Our 75 minute demo showcased three different techniques at three different attainability levels: rapid N2O infusion (within anyone’s reach); centrifugation (uncommon, but not beyond reach); and rotary evaporation (out of most people’s reach).

Rapid Infusion:

Rapid infusion makes flavored liquors almost instantly using nothing more than an iSi whipped cream whipper.  This technique works really well, and anyone can do it.  Briefly: put any porous item into a cream whipper, charge it with N2O, swirl it for about a minute, vent, strain, and drink. Read this post for my blow by blow.

Infusing with the ISI.

Many readers have commented that the liquors they’ve made with this technique improve after standing for several minutes.  I have also noticed this effect, but I don’t understand it (comments anyone?)

We made three cocktails with rapid  infusion:

Spicy Ballsy Bullshot:

The standard bullshot is beef bouillon, vodka salt and pepper. Beef bouillon isn’t so great, and you wish you could use reduced beef or veal stock – but high gelatin content makes the stocks solid jellies at cocktail temperatures. What to do?  Get rid of the gelatin. Freeze-thaw clarifying removes the gelatin from stock so you can reduce it a lot without turning it to glue (see the technique here). We made a very, very beefy 1 liter of reduction from 2 gallons of stock. We wanted to add some spice to the vodka so we used rapid N2O infusion to add some jalapeno flavor.  Most hot pepper infusions tend to get very spicy without tasting a lot like peppers. N2O infusions capture both heat and taste. We garnished with a pickled cherry tomato, which made the drink supremely satisfying.  It’s best enjoyed at the beginning of your evening or brunch, as a bracing short-poured drink –which is how we served it.

Ingredients:

8 liters veal stock
Water (the amount depends on how jellied your stock is)
1 liter vodka
60 grams of seeded sliced jalapeno pepper
4-8 gram N2O Chargers
Lime juice
Splash of water
Salt
Pickled cherry tomatoes

Freeze-thaw stock technique:

Add enough water (or vegetable stock) to the veal stock so that, when set, the stock won’t be too gelatinous.  Heavily set stock won’t work –your yields will be low and the stock will take forever to clarify.  Ideally, the stock shouldn’t fully set at all (you want the equivalent of 5-7 grams of sheet gelatin per liter of liquid, if that is helpful). Heat the stock to make sure it is homogeneous, pour it into 2 hotel pans, and let the pans sit in the fridge a couple of hours (this gives the gelatin time to cool down and do its thing). Freeze the stock overnight, or until completely frozen. Line 2 perforated hotel pans with 4 layers of cheesecloth and add the frozen stock (don’t use a torch to get the frozen stock out of the hotel pans! Use brute force). Place the perforated pans over deep hotel pans and let the stock thaw for a day or two in the fridge; make sure your fridge isn’t too cold. The liquid that drips from the thawing block will be clarified veal stock without gelatin (for more on clarification see here).  After the clarification step, reduce the stock down to 1 liter.

An alternate, faster technique: clarify the consommé in the traditional manner with an egg raft, allow it to cool down to 40 Celsius, and add 1 gram or so of Corolase 7089 enzyme per liter. Corolase (from AB Enzymes) will eat the gelatin. Wait half an hour and reduce your stock to 1 liter.

Jalapeno vodka technique:

Divide your jalapeno and vodka into 2 batches. Add one of the batches to a half-liter ISI cream whipper, charge with 2 N2O chargers, agitate for 1 minute, then vent and open the whipper. Allow to rest for 1 minute, then strain the pepper from the vodka. Repeat with the second batch and allow the liquor to rest for 10 minutes before using.

The drink:

Mix vodka and consommé in equal parts. Add lime juice and salt to taste. You may add water if it’s too strong for you, or an ice cube or two, and chill it in the fridge or freezer ‘til it suits your fancy.  Serve in shots garnished with a peeled pickled cherry tomato.

The crew: Grace, Nastassia, Jerry (our webmaster), AJ, Victor (who actually fried the puffs), and Clifford.

Chocolate N’Lemons, the Germanfrancisco Treat:

My wife is the inspiration for this drink; while living in Frankfurt for four years she picked up a taste for eating chocolate ice cream with lemon sorbet. For the drink base we made a chocolate vodka with cocoa-nibs; good tasting nibs, like Valrohna’s, are essential for this recipe.  We have tried three other types of nibs, including some expensive ones, and we don’t like any them. Look for nibs that don’t taste burned or overly acidic.

Ingredients:

500 ml vodka
75 grams Valrhona cocoa nibs
2-8 gram N2O chargers
Lemon juice
Simple syrup 1:1
Candied Ginger
Pinch salt

Chocolate vodka technique:

Add the nibs and the vodka to a half-liter cream whipper (changing the size might change the recipe). Charge with 8 grams N2O and swirl/shake for several seconds, then charge with an additional 8 grams of N2O.  Continue to agitate for a full minute and let rest an additional 20 seconds, then vent and open the whipper (here’s a tip: hold a quart container over the whipper as you vent;  once the whipper starts to sputter tilt the container to catch the liquid.  You don’t lose liquid and don’t make a mess). Allow the liquor to stay in the whipper for another minute or so, until the bubbling starts to subside).  Strain out the nibs and pass the vodka through a coffee filter.  Allow to rest several minutes before using. The leftover nibs aren’t very good –all that remains is the bitterness.

The drink:

Combine 2 parts chocolate vodka, ¼ part lemon juice, 1/3 to 1/2 part simple syrup, and a dash of salt. Stir briefly with ice, strain into an old fashioned glass, and garnish with candied ginger.  This recipe requires very little sugar, even though the cocoa nibs are unsweetened, because the infusion technique leaves the bitterness behind.

Bangkok Daiquiri

A fairly straight-ahead daiquiri recipe, using rum that we infused with Thai basil, cilantro, and orange peel.  Though daiquiris are normally made with white rum we tried this recipe with the aged rum by our sponsor, Zacapa — different, but still great.

Ingredients: makes 2

150 ml rum
10 grams Thai basil
5 grams cilantro
10 grams orange peel (pith removed)
ISI cream whipper
N2O charger
1 oz simple syrup 1:1 (can be increased to 1 1/2 oz for a sweeter drink)
1 1/2 oz strained fresh lime juice
Pinch salt

Technique:

Add the rum, Thai basil, cilantro, and orange peel to the whipper and charge with N2O.  Swirl the whipper for 30 seconds, allow to rest for 30 seconds more, give it a final swirl and vent the N2O to atmosphere.  While venting, hold the whipper upright so the liquid stays inside. If possible, let rest another 30 seconds.  Open the whipper and strain the infused rum into a metal shaker. Add simple syrup, lime juice and salt and shake vigorously with plenty of ice for 12-15 seconds.  Strain into 2 coupes.  Drink.

Centrifugation:

Centrifuges separate mixtures based on density – like oil from water, or solids from liquids — by spinning very quickly. The spinning generates centrifugal force that causes products to separate that would never separate due to the force of gravity alone.

Pouring clarified fig juice from a centrifuge bucket.

There are several reasons centrifuges aren’t widespread in kitchens.  They are expensive. They can be dangerous. And, perhaps most importantly, chefs just don’t know which ones to buy. Centrifuges that don’t spin fast enough or have inadequate capacity are useless, and centrifuges that have more capabilities than a chef needs are huge, mega-expensive, and therefore worse than useless. After a couple years of testing I recommend one type of inexpensive and versatile centrifuge: the 3-liter benchtop.  As the name implies, these guys can handle 3 liters per batch in their swinging bucket rotors, and the good ones can generate force in excess of 4000 times the force of gravity.  They are about 2 ft x2 ft x1ft.

I have two Jouan 3-liter centrifuges, which I mainly use to clarify juice. I paid a grand total of 350 dollars including shipping for both because I’m an eBay ninja.  If your kung-fu isn’t as strong, expect to pay $1000-$1200 a pop. Even at that price they pay themselves back pretty quickly if you make a lot of juice. With both of them running I can clarify about 18 liters per hour. Yields are incredible –much higher than with any other clarification technique. Expect 75-95% yield depending on the water content of your product. The basic technique: blend fruit in a Vita-Prep either alone or with a liquid (usually liquor), add 2 grams of Pectinex SP-L enzyme per liter or product (the enzyme breaks down the fruit’s pectin and hemicelluloses that prevent complete clarification. You can get some from us), let the puree rest for 20 minutes (so the enzyme can do its thing), and spin it at 4000 times the force of gravity for 15 minutes. Strain the juice and put it through a coffee filter.  The solids will be left behind in the form of a sometimes delicious puck of sludge.

Here are the drinks we made with the fuge:

Bananas Justino (pronounced who-steeno)

We made this drink for the Star Chef Congress Cocktail party.

Pouring Bananas Justino at the Congress Cocktail Party

We blend bananas, vanilla bean and Zacapa 23 rum, then clarify; pour over coconut water ice cubes (start with Taste Nirvana coconut water, the best we’ve found) squeeze in a lime and toss in a star anise for aroma. Done.

Ingredients:

Zacapa 23 Solera Rum
Bananas
Vanilla beans
Pectinex SP-L
Limes
Water
Coconut Water
Star Anise pods

Technique:

Per 750 ml bottle of rum add 3 ripe bananas, half a vanilla bean, and 2 grams Pectinex SP-L. Blend in a Vita Prep and let rest 20 minutes. Spin at 4000 g’s for 15 minutes and strain through a chinois and then through a coffee filter. Freeze coconut milk into 1 ounce ice cubes. Put ice cubes in an old fashioned glass, pour banana rum over the ice, stir briefly, then squeeze a quarter lime into the glass and garnish with star anise.  If you want you can keep the rum cold and water it slightly before pouring. If your limes aren’t juicy enough you can add some extra lime juice. Damn delicious.

September Issue

This is the drink I made for Jeffrey Steingarten and Dave Chang’s Vogue party during Fashion Week. It’s based on concord grapes and rye whiskey. We used McKenzie Rye from the Finger Lakes Distillery because it has a strong rye nose (smells just like the grain) that stays with the drink even after it’s mixed. We used Root, a delicious root beer liquor from Pennsylvania, like you would bitters –just a couple of dashes per drink.  It doesn’t make the drink taste like root beer –it just rounds it out. For acidity we used lemon, and for sweetness we used maple syrup.  Everything but the lemon is local to us New Yorkers. We garnished the whole shebang with maple-candied lemon peel.

September Issue.

We made our own concord grape juice.  It’s a pain in the behind, but worth it.  No store-bought concord is as good as the stuff you make yourself, since you can control just how long the pulp stays with skins.  Unfortunately you can’t just blend concord grapes to make juice.  If you blend them, the seeds will make a tannic, bitter juice. So you have to crush the grapes instead. We first passed the grapes through an old-school ice crusher, then added enzyme and processed them in a modified chocolate grinder.  After that, we clarified them in the centrifuge.

Nastassia and the modified chocolate grinder crushing concord grapes.

We served this drink with a side-shot of Nils’ favorite –Scotch and dry roasted peanuts blended and re-distilled in our rotary evaporator – to make our version of a peanut butter and jelly drink. Not an original combination, but a delicious one worth revisiting.

Ingredients:

2 Parts McKenzie Rye
1.3 parts concord grape juice
1 part water
0.5 parts strained lemon juice
0.25 parts maple syrup (grade B)
Pinch salt
3 dashes Root Liquor per 2 oz rye
Maple-Candied Lemon Peel (recipe below)

Technique:

Mix everything but the lemon peel together and chill it with liquid nitrogen (or mix it before hand, freeze it and shake it in a quart container; see my post on Cocktail Science).

Maple-Candied Lemon Peel

People seem to like these –I know I do.  Just peel long slices of lemon rind off the lemon (we get 8 per lemon), making sure to get only the flavedo (the yellow part) and not the albedo (the white part). Blanch the peels 3 times quickly in boiling water and shock them in ice water.  Vacuum bag them with cold maple syrup and simmer the bag in water for 20 minutes. Cut open the bag and put the peels and syrup in a pan to reduce the maple syrup a bit so the peels will gel when cooled.  I don’t know the temperature; we do it by eye.  Lay the peels on a silpat to dry.

Carbonated Figroni

Hendricks gin, Aperol, clarified mission figs, a squeeze of lime, and bubbles. What could be better? How about that same cocktail garnished with a cucumber that’s vacuum-infused with Hendricks, Dolin white vermouth (not the dry one), simple syrup and salt.

Figronis waiting for vacuum infused cucumbers.

Ingredients:

2 parts Hendricks gin
2 parts Aperol
2.5 parts clarified mission fig juice (blend figs with enzyme and centrifuge as above –just make sure to clean and trim the figs well so they don’t have a dirty aroma)
Pinch of salt
CO2

Technique:

Mix everything together, chill and carbonate 3 times at 40 psi (you carbonate three times to get rid of entrained air and bubble nucleation sites). Garnish with a squeeze of lime and a vacuum infused cucumber.

Rotary Evaporation:

Rotary evaporators are laboratory vacuum stills.  They operate at low temperatures in a low-oxygen environment. They can preserve flavors that might be damaged during ordinary distillation.  Rotovaps are also very efficient at recovering all the flavors in a distillation rather than letting them boil into the ether.  Walk into a room with a properly running rotovap and you smell nothing –all the aroma is in the booze. For a full explanation, see the Rotovap primer.

Even though it is illegal to distill alcohol (even for personal consumption, even if you don’t sell it) I always distill alcohol-based mixtures because I have found water based distillations weak and disappointing –until now. I have recently developed a technique for legal distillation using water –see my post on legal distillation. I’m not yet 100 percent satisfied with the technique, but Starchefs was the first time I have demo’d legal distillation in public, and people seemed to enjoyed it.  I made a legal Thai basil and orange peel liquor so folks could compare it to the Bangkok Daiquiri (instructive, even though the spirit base was different.)

Nils pouring shots of rotovapped liquor.

Lastly, we presented a rotovap concept piece –definitely not feasible for a bar:

Beaumes de Venise Mutant Sidecar

Beaumes de Venise (BdV) is a sweet Muscat wine from the Rhône Valley. We like it a lot.  We also like the brandy that we make from it in our rotary evaporator.  Since one of the main flavor notes of the traditional side-car is orange, we thought the Muscat-redolent BdV-brandy would be great in a sidecar.  We had two problems –the sidecar needs the oak flavor of an aged brandy to be balanced properly (which our BdV brandy didn’t have), and distilling the alcohol off the BdV left us with a lot of left over de-alcoholed wine that we didn’t want to waste.  Normally, we would reduce the leftover wine at around 45 C in the rotary evaporator to syrup.  BdV syrup is nectar of the gods, but it takes a long time to make. I didn’t have five hours of constant attention to devote, so instead we made the leftover wine into a fantastic sorbet using liquid nitrogen.  We served the sorbet as a sidecar to the sidecar.

Nils making Beaumes de Venise sorbet.

For the missing oak, I distilled some VSOP cognac in the rotovap and was left with a clear cognac distillate that retained a lot of the cognac’s character, but didn’t have any of the non-volatile oak notes that characterize an aged spirit. What was left over was a reduced solution of aged oak essence.  We served the clear cognac as-is and added the oak to our BdV brandy to make “aged” BdV brandy with which we made a traditional sidecar:

Ingredients:

2 parts mutant BdV brandy
1 part Cointreau
1/2 part strained lemon juice
Pinch salt

Shake and drink.

We finished only 5 minutes over our allotted time, after which we caught a breath –and a drink.

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Cooking Issues Radio Live, Tuesday

September 28th, 2010 · Uncategorized

Howdy,

Cooking Issues Radio will be broadcasting live on the Heritage Radio Network, today, Tuesday from 12pm – 1pm EST.   Call in your cooking issues questions live at 718-497-2128, or email Nastassia at lopez.nastassia@gmail.com and we’ll try to answer as many questions as possible.

Thanks so much for listening,

The Cooking Issues Team

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Turning Water into Wine: Legal Distillation

September 27th, 2010 · Uncategorized

by Dave Arnold

For years I have been distilling illegally in my rotary evaporator because the products are delicious. I don’t feel bad about being a scofflaw — our distillation laws are preposterous.

Nastassia flying the rotovap at Star Chefs

Distillation is defined in the United States as any process that separates ethanol from an ethanol-containing mixture. Unless you are licensed, distillation is illegal. There are no exceptions for personal consumption; adding botanicals to high-proof alcohol and re-distilling it for flavor (like gin) is verboten, even if you don’t raise the proof of the liquor. So most home distillers remain underground and won’t talk about their craft for fear of the government knocking on their door, and bartenders are unable to serve house-made distillates for fear of losing their liquor license.

The rotary evaporator, described in my primer here, is an amazing piece of equipment that makes some of the cleanest, purest, brightest tasting liquors I have ever tasted. Unfortunately, the handful of U.S. chefs that have them in their restaurants in the U.S. only distill water based products for fear of the aforementioned laws –a horrible pity. Once you have used the rotovap for liquor, water-based distillates are a disappointment. They smell nice, but they taste like lightly flavored water –nothing like the kick-in-the-teeth flavor punch you get from ethanol distillates. I have always been disappointed by water based distillations–until now.

It’s the Condenser Stupid!

To distill you must first boil something, and then re-condense it back into a liquid. The job of chilling a vapor and turning it back into a liquid is done by a device aptly named the condenser. In a rotary evaporator you have two basic condenser choices –standard cooling tube and cold-finger. Standard condensers have a long length of tightly coiled tube on the inside through which you pump coolant. The large surface area of the coiled tube coupled with the constant flow of fresh coolant makes for efficient condensing. For maximum flavor retention, you want this coolant to be as cold as possible without freezing your distillate to the coils. In practice, it is hard for me to get condenser temperatures below -20 C. You don’t want your distillate to freeze because then you don’t know how much distillate you have produced (it is difficult to judge from the rotating flask) and if, like me, you have installed a pump that lets you taste your product as you make it, you can’t taste. The standard condenser is what most everyone uses. It works great with liquor.

Rotovap setup with a standard tube condenser running propylene glycol.

The cold-finger condenser doesn’t have circulating coolant or coiled tubes. It has an internal sleeve that you fill with something cold –dry ice and acetone, for example, or liquid nitrogen. Because they are filled with super-cold fluid, cold finger condensers run much, much colder than standard condensers do. You should be able to run them at the same temperature as regular condensers by filling them with ice, salt, and water; this technique sucks so don’t bother trying it.

Cold finger condenser setup.

I’ve had a cold-finger condenser for years but it didn’t fit my old rotovap. I never bothered adapting it to that machine because I didn’t like the idea of freezing my distillate. But my cold-finger is compatible with my new rotovap. Experiment time.

I started by using one of my standard liquor recipes but distilling with the cold finger filled with liquid nitrogen (about -200 C) instead of my tube condenser at -20 C. The results were good, but I didn’t think they were better than normal (to be fair I didn’t taste side-by-side; more on that later). I chocked that up to a victory for tube condensers. During distillation, I noticed that a thin layer of frost formed on the cold finger almost immediately, even before the distillation proper started. Then I thought –hey, what if I ran water based flavors through this thing? Maybe the super-cold condenser would capture flavors that are lost in water based distillations in a standard condenser? The immediate formation of frost, and its implied condensation and capture of flavorful vapor, was encouraging.

Frost builds immediately in the condenser.

If I could get water based distillation to work it would be LEGAL!

Chocolate Vodka Side By Side:

I made some 120 proof Smirnoff vodka (by illegally re-distilling 80 proof Smirnoff) in a regular condenser. I then added equal amounts of cocoa powder to 1 liter of 80 proof Smirnoff and 600 ml of water (the amount of water in the bottle of Smirnoff). I then distilled the vodka/cocoa mixture in the regular condenser and the water/cocoa mixture in the cold finger. I tried to judge the amount I had distilled by looking at the remaining liquid level in my distillation flask –a difficult task. My aim was to distill 600 mls from the liter of vodka and add enough water to make a liter of 80 proof, and distill a little under 400 mls from the water based cocoa, then melt the distillate off the condenser using the high-proof Smirnoff to make a liter of 80 proof.

In a side-by-side, the illegal chocolate beat the legal one hands down — but there was still hope for the legal method. It was good. It was oodles better than any other legal distillate I’d ever made. I decided the Smirnoff was no good for these tests; I needed something higher proof. I didn’t want to use the 195 proof stuff you can get in the liquor store — it is horrendous – you’d rather suck on an isopropyl alcohol prep swab. Instead I looked online at Spectrum, the chemical supply house. It just so happened that they were running a special on 200 percent pure, anhydrous (no water), USP (food grade), ethanol (booze). They were selling it for only 16 dollars a liter –the equivalent of $6.40 a liter for 80 proof. I ordered some and tasted it. It was primo! I immediately ordered 16 gallons (a day later the price went back to normal –triple what I paid).

Lab-grade super-hooch.

I re-ran the experiment with the super-hooch. This time, my alcohol-based distillation consisted of cocoa powder plus 200 proof and water in the standard condenser, versus straight water and cocoa in the cold finger. Again I melted the water-based distillate off the condenser with booze, this time 200 proof. When I corrected both distillates for proof, the illegal chocolate still won –but not by as wide a margin. Legal was getting better, but still not up to par.

The Unscientific Re-Test

For several months I was too busy to pursue further legal distillation tests. Then I remembered I had promised to bring my rotovap to the 2010 Star Chefs demonstration, and the following occurred to me:

1. Crap, I don’t want to lug my chiller with all the tubes and propylene glycol to Star Chefs.

2. Crap, they never have enough power in the demo rooms and I’ll probably blow a circuit running the chiller and the rotovap.

3. They will have a boatload of liquid nitrogen at the event, which I could use to run the cold finger (they ran out last year so they over-ordered this year).

4. People might like to see a legal distillation demonstration.

Legal it would be.

Legal Distillation at the Star Chefs Demo (for the rest of the demo, see my upcoming post):

I decided my earlier tests were fundamentally flawed. I had been comparing the results of cold finger distillation to standard condenser distillation by trying to match the yield and proof of the cold finger product to the standard product. What if that method was biased against the cold finger?

For the Star Chefs demo I decided to focus only on making a delicious product with the cold finger. I vacuum bagged Thai basil and orange peel in ice water to thoroughly saturate the leaves and peels with water.

Mint in a bag

Experiments I had run with Tony Conigliaro at his bar 69 Colebrook Row in London (where he is allowed to re-distill with alcohol –the lucky cuss), showed that leaves not fully saturated wouldn’t give up their flavor as readily. You can’t blend the leaves to mingle their flavor with the water, either –blended herbs distilled with water in the rotovap taste brown and swampy. The swamp thing doesn’t happen when you blend herbs and liquor. In a side-by-side test, distilled blended mint + ethanol beat distilled vacuum saturated mint + ethanol; distilled blended mint in water was wretched, while distilled vacuum saturated mint in water just lacked power.

Tasting mint distillates

I loaded the saturated peels and Thai basil in the rotovap, sucked a vacuum, filled the condenser with liquid nitrogen, lowered the distillation flask into the water bath, and commenced to distill. I left Nastassia to finish the process while we went on with the rest of the demo. When she felt she’d pulled off all the water she could, we melted the ice off the condenser with the 200 proof and tasted. It was fantastic. Really fantastic. Nastassia claims it was good because the rotovap required a woman’s touch. I’m not so sure because she says that about everything.

The outcome of the demo left me very, very optimistic about the future of legal rotovapping.

Tips and Comments on Running the Cold Finger:

1. Running a cold finger isn’t the same as running a standard condenser. Do not add coolant to the cold finger until you have established a partial vacuum in the system. If you ignore this warning you risk clogging the vacuum intake of the condenser with ice crystals –a pain in the rear.

Watch out for condensation here.

2. It’s normal for the ice at the bottom of the cold finger to melt under heavy distillation, even with something as cold as liquid nitrogen as your coolant –condensing water requires a lot of power.

Even though liquid nitrogen is super-cold, you will see liquid water at the bottom of the condenser and in the receiver flask. This is normal.

3. A mixture of dry ice and 200 proof ethanol is food grade and will probably work as well as liquid nitrogen. Dry ice isn’t as cold as, but has much more cooling power than, an equal amount of liquid nitrogen. Dry ice is also easier for most people to source. Unlike me – I have liquid nitrogen dribbling out my ears.

4. As a corollary to 3, you will need a lot more liquid nitrogen than you think. It will take many, many liters to condense 1 liter of product. Keep adding LN throughout the distillation (it runs out quickly). Don’t be alarmed, but you will get a huge vapor plume once the distillation starts in earnest.

The plume.

5. Make sure to melt the distillate off the condenser immediately with 200 proof ethanol. I have no scientific proof, but every distillate I have made with water loses its aroma very quickly. I feel melting it with liquor helps fix the flavor, but I’m willing to be proven wrong.

6. It is extremely difficult to determine how much product you have distilled off your mixture in a cold finger condenser. Some protocol has to be devised to figure this out or recipes won’t be repeatable (suggestions anyone).

Up for Comment:

My old theory as to why liquor-based distillation is inherently better than water-based was threefold:

1. Flavor is captured better in distillations that go through a range of boiling points with large amounts of distillate produced all the time –the way an ethanol water system works. The range of boiling points in a water based distillation is much lower, plus many of the more volatile compounds that boil at significantly lower temperatures than water will be boiled off unnoticed in a water based distillation.

2. Ethanol and ethanol water mixtures are inherently better at carrying volatile aromas and flavors than water alone.

3. Once distilled, ethanol mixtures hold volatile flavors better.

How do these theories jibe with the new water-based distillations?

First, I am willing to be challenged on all of these theoretical points, as they were not arrived at through experience, not scientifically.

If my theories are correct, point 1 is partially addressed in the legal method, because the trace amounts of flavor that get lost in a water based distillation in a standard condenser freeze on the side of the cold finger and would then be dissolved in straight alcohol at the end of the distillation run, which solves the problem from theory 3.

As to the first part of theory 1: that a range of boiling points in a distillation leads to better flavor and theory 2: that ethanol is a better flavor carrier than water, I guess it’s open for discussion. In fact, I haven’t been able to devise a good side-by-side test where legal distillation was as good as illegal –so maybe these theories are correct, and illegal distillation is inherently superior. The success I had at Star Chefs, however, leads me to think my theories should be revised.

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Cooking Issues Radio, Pre-Recorded Sunday

September 11th, 2010 · Uncategorized

This Tuesday, Dave will be preoccupied with the French Culinary Institute’s Sous Vide Intensive Course, so this week’s Cooking Issues Radio Show will be pre-recorded tomorrow (Sunday). 

Email questions to Nastassia at lopez.nastassia@gmail.com and we’ll answer as many as possible.  Or call in to the show from 2pm-3pm EST at 718-497-2128 (you can hear yourself when we play tomorrow’s show during our regular Tuesday at noon time slot) 

Thanks for listening!

The Cooking Issues Team

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Cocktail Science in General:Part 2 of 2

September 8th, 2010 · Uncategorized

by Dave Arnold

This, then, is the second part of the mega cocktail science post. For the science of ice, temperature and dilution, see Part 1.

Eben Klemm, graduate cylinder, paper cup, and head of Nastassia --Dave Arnold 2010

Here I’ll deal with proper temperature, proper dilution, and the different qualities of shaken and stirred drinks. I will also talk about good batching techniques, and then you’ll get, at no extra charge, the Thomas Waugh section promised last week.

Dilution:

Many folks think all drinks should be diluted some standard amount; 25% is often bandied about. Not true — there is no single ideal dilution. In Part 1 I showed that the average stirred cocktail is both warmer than, and less diluted than, the average shaken cocktail –so at a minimum there are two different ranges of good dilutions: one for shaken and one for stirred drinks.  But it’s more complicated still. In a series of blind taste tests with bartenders Kenta Goto, Scott Teague, Eben Klemm, Don Lee, Chad Solomon and Christy Pope, we made Pegu Club cocktails and sidecars with different known dilutions, hoping to find the ideal. No luck.  Preferences depended on a number of factors including palate fatigue (is this your first drink, or your third?), and what had been consumed prior and after. A drink tasted balanced at a low ABV (alcohol by volume), went out of balance as the ABV went up, but then come back into balance again at an even higher ABV. The more components there are in a drink –spirits, acid, sugar, bitters, etc. the more complicated dilution becomes, because each component may respond to dilution differently. For more details see Ideal Dilution Through %ABV.

The dilution crew from left to right: Kenta Goto, Don Lee, Scott Teague, Eben Klemm, Christy Pope, Nils, Chad Solomon, Dave, Nastassia (and no, we didn't use Photoshop)

Temperature:

Many people believe drinks should be as cold as possible. Not true. No drink should be served colder than -20°C or it’ll be painful. Straight shots of certain spirits, like 80 proof vodka and aquavit, start to crystallize at about -23°C, so if they are clear they probably won’t hurt. Those same straight shots are really enjoyable between -16 and -18°C, where the temperatures accentuate  sweetness, minimize the perception of alcohol, and produce a viscous body that is supremely enjoyable. Lucky for us, this is the temperature range of most home freezers. Vodka in the freezer is a good idea – as you already knew. On the other hand, minus 18°C is waaaay too cold for most booze and for most mixed drinks. Most over-chilled drinks are dull and lack flavor and aroma. Shaken drinks usually taste best between -5°C and -10°C. That’s lucky, because properly shaken drinks are right in that range. Most stirred drinks taste best between -0.5°C and -7°C. Lucky again;  most stirred drinks are in that range.  These observations are my general rules of thumb derived from side by side taste tests over the years. Many people enjoy over-chilled drinks because they like the sensation of biting cold.  That’s fine, of course –but if they analyze the overall drink, they’ll notice that flavor is compromised.

Temperature can also radically affect the balance of a drink. I’ll give you an example:

Bottle Strength GnT’s:

A while back I was in the habit of making bottle strength gin and tonics.  I’d re-distill gin to bring it above bottle proof without changing the flavor profile, then add quinine sulfate, sugar, clarified lime juice, a pinch of salt, and enough water to bring me back to bottle proof.  I’d chill the whole batch down to -20°C and carbonate it.  I kept the bottle in a -20°C chiller and poured shots as needed.  By the time the customer drank the shot, it’d be up to about -18°C.  Remember when I said most drinks aren’t good this cold? Well, I balanced this drink specifically to taste good at that temp.  They were delicious –carbonated, stinging cold, just the right acidity and sugar, not overly alcoholic tasting, with a syrupy body.  Problem was, those shots only tasted balanced between -18°C and -15°C.  Any warmer and they started to go out of balance –way out of balance.  The taste just flew apart.  The problem was so bad that I would get visibly angered if people didn’t drink the shot right away. Since I can’t guarantee people will not sit about idling chatting instead of drinking, I no longer serve the drink. Bottle strength GnT’s are an extreme example, but the balance of any drink is affected by temperature.

Postulate of Classic Cocktails

I have distilled many spirits and made many drinks that, like the bottle strength GnT, need precise temperatures and dilutions to be delicious.   I have realized that these spirits and drinks will never become popular, and they don’t have what it takes to become classics.  My postulate of classic cocktails:   classic drinks are those that maintain deliciousness over a wide range of temperatures and dilutions – they can withstand bartender abuse and interpretation, and they don’t wither in front of a lazy drinker chatting up their date.

Texture

Temperature and dilution are fairly easy to measure.  Texture is much more difficult.  After our first Science of Shaking seminar at least year’s Tales of the Cocktail, everyone wanted to know how we would measure texture, and whether a bartender’s shaking style had a significant influence on drink texture.  We set out to find the answers.

In our first test we had Alex Day, Kenta Goto, Don Lee, and Chad Solomon all shake daiquiris. Eben Klemm, Audrey Saunders, Nils and I  tasted the drinks blind.  Apart from varying  ice crystal quantities floating on the surface, which we ascribe to straining technique, the drinks tasted fairly similar.  See the post here.

That different bartenders using different shakes produced similar drinks, in conjunction with our findings that shaking style and ice types didn’t affect temperature and dilution, led me to believe that unless a drink contained a foaming agent like egg white, the texturizing effects of shaking were fleeting.  I figured the air bubbles and ice crystals in a shaken drink just floated to the top and were gone after the first sip. Wrong.

Shaking versus Stirring –the blind-fold taste test:

Cooking Issues crew dons blindfolds.

We gathered another group of bartenders: Eben, Thomas, Joaquin Simo of Death and Co, Dana Cory of Lady Jay’s, Karen Jarman of Painkiller, and Nils, Nastassia, and me.  We chose two classic stirred cocktails: the Manhattan and the Negroni.  We made each drink four ways: stirred fast, stirred slow, shaken and poured through a single strainer, and shaken and poured through a double strainer.  The drinks looked so visibly different that we tasted them wearing blindfolds –a real blind taste test. To my surprise, every one of us was able to distinguish between the shaken and stirred drinks.  Almost always we liked the stirred ones and dis-liked the shaken ones.  The only exception was the double-strained Negroni, which some people thought was good –but not as good as the stirred. Although these tests didn’t control for dilution, It was clear that dilution wasn’t the only thing making the cocktails different. Our ability to tell the difference between the drinks was maintained for at least 5 minutes, but disappeared by 8 minutes. Contrary to what I had believed, a textural element  introduced by shaking was maintained for at least several minutes. Also –turns out we like our stirred drinks stirred, not shaken.

Fake Shake 1:

If shaking really does introduce some lasting texture to the drink, how do you emulate thattaxture in large demos where it is impossible to shake to order?  We blind tasted 4 daiquiris: fresh shaken, diluted and chilled in a freezer, diluted and chilled in a freezer then spun in a blender for service, and chilled with Liquid Nitrogen.  Everyone liked the fresh shaken best.  The Liquid Nitrogen was a close second.  The blender was bad –the bubbles were too big and frothy (this is no indictment of blender drinks –this drink had no ice, just liquid).  The merely chilled cocktail was what it was –rather flat.

To visualize what was going on up-close, I employed my kids’ toy microscope –the Eyeclops (by the way they make some crazy night vision goggles.  I bought them “for my kids”).

Eyeclops, a really cheap video microscope. I stole it from my kids.

We made drinks, poured them on the white table, and took pictures of them with the Eyeclops.

Using the Eyeclops.

Under 200x magnification, stirred drinks appear blank, but both strained and unstrained shaken drinks had lots of tiny bubbles — straining a shaken drink removes ice crystals, but not air bubbles.  Drinks chilled with liquid nitrogen, which aerates as it chills, also had bubbles, but not quite as many as the shaken drink –lending credence my theory that LN is the best chilling mechanism for shaken drinks in  super-high-volume scenarios.

Drinks chilled different ways under 200x magnification

Fake Shake 2:

Not everyone has liquid nitrogen, so we tested some easier ways to fake the shake. I made a batch of whiskey sours, some of which I pre-diluted and put in the freezer.  At tasting time I shook one drink to order, poured one straight out of the freezer, shook one of the pre-chilled guys in a quart container, and shook the last one in a quart container filled with the springs from hawthorn strainers, for extra aeration. The drinks were noticeably different.  One taster liked the drink straight from the freezer –a texture-hater apparently, because he liked the drink shaken with the springs the least. Most people liked the freshly shaken drink best, with the drink shaken in the quart container a close second.  The one shaken with springs was similar to the other two shaken drinks, just a little more airy.

Stir Texture = No Texture,  and the best stirred drink:

I have been saying for a while that stirring is a technique that chills without providing texture –it adds nothing extra.  To test this theory we blind-tasted drinks stirred live versus drinks that were pre-diluted and chilled.  They were indistinguishable.  The best stirred drinks, therefore, can be made by pre-batching the drink with water and chilling it in a freezer.  Just make sure to use a freezer that isn’t too cold.  You don’t want to serve the drink much below minus 7C.  Drinks made this way are effortless and consistently perfect.

The last question to tackle: how to figure out the amount of water to add to your batch recipes.

Scientific Batch Recipes:

If you want to pre-batch a cocktail and chill it in the freezer, it is helpful to know how much water to add. Diluting to taste isn’t a good idea. It’s likely you won’t be diluting at the proper serving temperature, and temperature has an effect on your perception of dilution.  Here’s the best way to come up with a batch recipe:

Gather enough ingredients to make a cocktail and mix them together without ice. Better yet,  mix enough for two cocktails and your measurement inaccuracies will be proportionally less;  if you make more than two drinks at once the mix might not shake or stir properly.  Make sure you measure by volume (most cocktail recipes are by volume, and the density of cocktail ingredients differs widely). Make sure you measure accurately – no “half a lemon” nonsense.  Bitters are tough. I tend to ignore them in my calculations unless a lot is included. Weigh the undiluted cocktail as accurately as possible. Now chill the drink exactly as you normally would.  If you normally stir for 20 seconds, do that.  If you normally shake for 15 seconds, do that.  When you are done, strain the cocktail off the ice. It is important to leave as little of the drink in the shaker or mixing glass as possible.  Now weigh your drink.   Taste the drink.  Do you like it? Then, bang – you know how much dilution that drink should have.  If you don’t like it, go back and repeat ‘til you do.

While the above technique is a good start, it introduces major inaccuracies because some of the cocktail remains trapped in the ice after you strain it — we call this trapped liquid ‘holdback’, and you need to correct for it.  Here’s how: after you strain your cocktail, dump the ice into a tray, recover the last bit of liquid from the ice, weigh it, determine what percentage drink you think it is (this is a non-scientific, best guess kind of thing –like hey that tastes like 75 percent water). Do the math (see below) and re-calculate the cocktail based on the estimated holdback.

The liquid left in the ice after you make a drink leads to calculation errors. You have to figure out how much of your initial mix you lost --we call it holdback.

Two Example Batch Calculations (With and Without Holdback Correction):

Whiskey Sour Basic Recipe

2 parts whiskey 45% abv
1 part strained lemon juice
0.5 parts 1:1simple syrup
Tiny pinch salt

Total Batch: 3.5 parts

We jiggered up one cocktail and it weighed 101 grams. Eben Klemm shook it using his normal technique.  When we strained the drink  it weighed 157 grams (it was -4°C).  We then dumped the ice into a tray and recovered 18 grams of liquid.  We tasted it and it seemed to be about 25% initial mix. This is unscientific, but the best we could do without good equipment.

Givens:

Water calculation without holdback (inaccurate):

 

Water calculation with holdback (more accurate):

Notice there is a large difference between the two calculations. We re-ran the test, this time with Thomas Waugh doing the shaking. His drink had 2.4 parts of added water. We settled on 2.3 parts of added water for our master recipe. Here it is:Whiskey sour with proper dilution:2 parts whiskey 45% abv1 part strained lemon juice0.5 parts 1:1simple syrup2.3 parts waterSome saltTotal batch: 5.8 parts. Total dilution (percent of initial mix volume in water added to drink): 63% ! Approximate Final ABV: 15.5%Example two: Manhattan Basic Recipe:2 parts rye whiskey 45%abv1 part sweet vermouth2 dashes bittersTotal Batch: 3 parts (bitters not counted here)The mix for 1 cocktail weighed 77 grams. Thomas stirred and strained the drink. The final drink weighed 113 grams (it was -1.2°C). We dumped the extra ice into a tray and recovered 11 grams of liquid. We estimated the liquid was 20% mix.Givens:

 

Water calculation with holdback:

 

 

Manhattan Basic Recipe with proper dilution:

2 parts rye whiskey 45%abv
1 part sweet vermouth
some bitters (sorry, I said bitters were tough)
1.5 parts water

Total batch: 4.5 parts. Total dilution (percent of initial mix volume in water added to drink): 50% !  Approximate Final ABV: 20%

Secret Bonus for Reading this Far –Salt:

The secret ingredient in our cocktails isn’t love, it’s salt. A pinch of salt added to most cocktails brightens them up and rounds out the flavor tremendously. You don’t need a lot.  Add so little you don’t even perceive saltiness –I call it “sub-threshold salting”.  Sugar and vanilla also do interesting things in sub-threshold quantities.  When I distill liquor, I usually add a small amount of salt and sugar  – not enough sugar to add sweetness.

Bonus –Thomas Waugh from Death and Co tells us how all this business has affected the way he tends bar.

 

Thomas Waugh, famed bartender at Death and Co.

 

by Thomas Waugh

Upon completing our investigation on the variables of stirring, here are some humble suggestions for the everyday bartender:

1.   Chill your mixing (stirring) glass — ice works, as does a fridge or freezer.

2.   If making multiple drinks, build the shaken drinks first, but without ice, and set aside.

3.   Continue to build the stirred drinks  in the cold mixing glass.

4.   Stir without breaks until the stirred drink is cold (we found that 45 seconds is an ideal stirring period).

5. Crack some ice to maximize surface area. Note: too much cracked ice will hinder the control of your dilution rate.

6. Pour stirred drinks first.

5.   Finish the order by adding ice to your shaken drinks and shaking, as shaking is a much more efficient technique.

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Live Tuesday, Cooking Issues Radio

September 6th, 2010 · Uncategorized

Cooking Issues will be broadcasting live on the Heritage Radio Network tomorrow (Tuesday) from noon to 12:45 EST.  We’ll answer all of your cooking issues via phone and/or email.

Give us a call at the Heritage studio at 718-497-2128 or email Nastassia at lopez.nastassia@gmail.com and we’ll answer as many questions as we can.

Thanks for listening!

The Cooking Issues Team

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Cocktail Science in General: Part 1 of 2

September 2nd, 2010 · Uncategorized

by Dave Arnold.

At this year’s Tales of the Cocktail, Eben Klemm, beverage director for BR Guests restaurants and the author of The Cocktail Primer: All You Need to Know to Make the Perfect Drink; Thomas Waugh, bartender extraordinaire at Death & Co; and I did a seminar called The Science of Stirring –a follow-up to last year’s presentation, The Science of Shaking. Rather than post a summary of the seminar, I’ve taken on the more ambitious task of summarizing everything I’ve learned about cocktail science over the past year.

This year's cocktail crew: Me, Eben Klemm, and Thomas Waugh

I’m breaking this post into segments. The one below is about shaking, stirring, temperature and dilution; the next one addresses how you perceive temperature and dilution, texture, and notes on batching drinks.  Stick with it, and at the end of the second segment you’ll get a bonus:  Thomas Waugh talking about how all this science stuff affects a real live bartender.

For those of you without patience: the Short Story

Cocktail shaking  is a violent activity.  If you shake for around 12-15 seconds (though shaking longer won’t hurt), and if  you aren’t too lethargic, neither the type of ice you use nor your shaking style will appreciably affect the temperature or dilution of your drink. Shaking completely chills, dilutes and aerates a drink in around 15 seconds, after which the drink stops changing radically and reaches relative equilibrium. Shaking is basically insensitive to bartender-induced variables.  See my post on the Science of Shaking.

Stirring is different. Think of stirring as inefficient shaking. It can take over 2 minutes of constant stirring to do what shaking can accomplish in 15 seconds. No one stirs a drink for 2 minutes, so the drink never reaches an equilibrium point. All the bartender-induced variables –  size of ice,  speed of stirring, duration of stirring, etc. — make a difference in stirred cocktails, so bartender skill is very important in a stirred cocktail.

Because stirring doesn’t reach equilibrium, stirred drinks are warmer and less diluted than shaken cocktails. Stirred drinks, unlike shaken ones, are not aerated. Stirring does not alter the texture of a drink –it merely chills and dilutes. A properly diluted cocktail stored at -5 degrees Celsius in a freezer is indistinguishable from a properly stirred one.

Don’t believe me?  The proof’s in the long story.

Long Story

The Equipment I Used for my Experiments.

I took temperature readings with a thermocouple.  I drilled holes into the bottom of metal shakers, pint glasses, and Japanese crystal stirring vessels and inserted thin stainless steel thermocouples with  ½ second response times.  I sealed the bottom of the containers with Mighty Putty, which made them water-tight and  allowed them to sit flat despite the thermocouples.  God bless Mighty Putty, may Billy Mays rest in peace.  I read the thermocouples using a Measurement Computing 8 channel thermocouple input module (Model USB-TC, a pretty good deal at $329). I recorded weights on a digital scale accurate to 0.1 gram.

The mixing vessels.

A Preliminary Rant on the Temperature of Ice:

Fact 1: Ice at 0°C can chill an alcoholic drink well below 0°C. This fact is counter-intuitive to many, but is an irrefutable consequence of the laws of thermodynamics. The universe likes increased entropy. If you want an actual explanation, see my first post on Cocktail Science. For visual proof, I submit the following experiment:

Zero degree ice chills drinks below zero!

I took ice from my freezer, put it in cold water,  and allowed it to sit for 15 minutes. I then took some of the ice and water and put them into a mixing glass with a thermocouple and vigorously stirred for 120 seconds to ensure that everything was at 0°C.  I drained the water from the ice, put the ice into a mixing glass with room-temperature vodka, and started stirring. Less than 30 seconds later my vodka was colder than 0°C.

Fact 2: Bar ice is almost always at 0°C unless it comes straight from the freezer. People have a hard time accepting this fact. As a test, I froze a large ice cube with a super-thin hypodermic thermocouple probe in the center.  I put that ice cube, along with some run-of-the-mill ice cubes for insulation, into a blast freezer for 4 hours until everything was at -20 C.  I then put the entire batch into a plastic container and waited.  In under 20 minutes, the large ice cube was within 0.5 degrees of zero.

Even big ice doesn't stay colder than zero for long.

Why?: 1. The ice warms up so quickly because it is a very good conductor of heat – four times better than stationary water.   Unless water is moving (convecting), it isn’t a good conductor. 2. Ice has a low specific heat — i.e., it doesn’t take a lot of energy to heat it up.  It takes twice the energy to heat a pound of water 1 degree than it does to heat a pound of ice. For more on specific heat, see the Anomalies of Water Page.

Fact 3: Even if your ice is below 0°C, it won’t chill a drink that much better than ice at 0°C. Ice’s tremendous chilling power doesn’t come from the energy required to heat it up, but from the energy required to melt it. It takes 0.5 calories to heat a gram of ice from -1°C to 0°C (this value is called the specific heat of ice,) but almost 80 calories to melt that same gram (this value is called the heat of fusion of water). To put it another way, melting 1 gram of ice provides the same chilling power as bringing that same gram of ice from -160°C to 0°C.  If you chill a cocktail with 150 grams of ice at -10°C, the amount of extra chilling power from the super-frozen ice is equivalent to melting only 9.5 grams of ice.

An experiment repeatedly conducted by Eben Klemm and Thomas Waugh indicates that super-frozen ice may actually chill drinks slower than ice at 0°C (even though the drinks reach a slightly lower final temperature).  I repeated the experiment once with them and once by myself, and my results matched theirs (see the chart below).  I am not certain why, but my guess is that melting ice chills three ways: through conduction, convection of the drink, and convection of the melt-water; whereas chilling without melting only uses conduction and convection of the drink.

The ice stored in the freezer gets the drink slightly colder than the ice at zero degrees, but takes longer to chill the drink. Initial drink volumes and temperatures were identical and the weights of ice used were equal within 5 grams.

The Fundamental Law of Cocktails:

Assumption: Bar ice is at 0°C.

Law: There is no chilling without dilution. There is no dilution without chilling. The only way ice can melt is by absorbing energy from its surroundings –by chilling.  Chilling and dilution are two sides of the same coin. This observation seems trivial, but the consequences are deep. For instance, many bartenders like to serve drinks with big rocks of ice because the big ice will dilute the drinks less over time. This is true, but it also will not keep the drinks as cold. You can’t have it both ways: you can’t  keep a drink as cold as possible while also diluting it as little as possible. Personally, if I were served an old fashioned I’d rather have the big rock and let the drink get a little warmer (it can get above 0°C pretty quickly when served with big ice) than let it get too watery.

Later in this post you’ll see some striking proofs of the fundamental law.

As a side note, not all chilling makes your drink colder.  Some chilling power is consumed in chilling your shaking or mixing vessel. This energy isn’t negligible –in stirred drinks especially, the type of container you use makes a difference. Metal shakers heat up and cool down quickly using minimal energy –they don’t affect your drink much.  Pint mixing glasses have more thermal mass than a shaker and absorb some energy from your drink.  Heavy Japanese crystal mixing glasses absorb the most of all.  Pre-chilling those glasses before making your drink mitigates these effects and makes them as good as –or better than, an un-chilled metal shaker. Some chilling power is also consumed overcoming the friction of mixing or shaking your drink, but this energy loss is negligible (for proof see the second experiment in The Science of Shaking II).  Lastly, some energy is lost to the surrounding environment. I ignore this energy loss, because the amount of energy lost during the mixing and shaking process is small. On the other hand, it is this energy loss to the environment that turns a drink to dreck  if it sits around waiting to be drunk.

An Apparent Exception to the Fundamental Law: The Surface Water Problem.

Everyone thinks that small ice cubes and crushed ice will inherently dilute a drink more than big ice cubes will. Here’s what’s really going on: crushed ice has a lot more water trapped on its surface than the big ice does. Big ice cubes have less surface area per gram than small cubes do.  Bar ice at 0°C has water on its surface, so big ice cubes have much less surface water per gram than crushed bar ice does.  This initial excess water dilutes your drink right away. After the initial dilution, the big ice and little ice go back to having the same chilling power. If you shake or spin the extra water off your small ice before you make a drink, it actually won’t dilute your drink any more than big ice will. For proof see my post: Does Crushed Ice Dilute More?

Chilling –Shaking vs. Stirring:

I have shown that ice can chill an alcoholic drink well below freezing.  Just how far below freezing is dependent on a number of variables: the initial temperature of the drink, the initial alcohol content of the drink, and how efficient your chilling is.  The amount of ice you use doesn’t really matter (so long as you use enough –see the Assumptions section of the Science of Shaking II post. Most drinks start at room temperature (unless you are making gin and tonics –shame on you if those ingredients are room temp). The initial alcohol content is determined by the recipe you use.  The only variable you really get to control is the efficiency of your chilling.

When chilling, stirring is just inefficient shaking.

Shaking is so violent that it accomplishes everything it needs to in about 15 seconds. After 15 seconds, the drink won’t chill much more, and the drink won’t dilute much more.  It’s reached relative equilibrium. The type of ice you use, how hard you shake (within reason –lazy shaking is no bueno), the style of shake, and how long you shake after 15 seconds doesn’t really matter. The long-winded proof of is in Science of Shaking II, but here is a chart from that post showing chilling curves for different bartenders and different types of ice:

This chart comes from last year's Tales of the Cocktail seminar. The top graph is Alex Day, the noted bartender. The second graph is Eben Klemm. Crazy Monkey is me, so named because I shook as hard as I could. I shook so hard that by the end of the shaking I couldn’t move my arms and had to jump up and down to keep going. Notice that even going crazy monkey, all of our final temperatures are about the same, regardless of shaking style and regardless of ice type.

Stirring is much more mellow than shaking.  To stir a drink to the same temperature plateau that a shaken drink reaches in 15 seconds, you might need to stir 1-2 minutes.  No one stirs this long, which means stirred drinks never reach equilibrium, which means stirring is complicated.  Here, a comparison of stirring versus shaking:

Shaken drink is in blue, quickly stirred drink is in red, and slowly stirred drink is in green. All drinks started with the same volume of liquor at the same temperature. Equal weights of un-cracked Kold-Draft cubes were used for each. Time is in seconds and T=0 represents beginning of shaking/stirring.

You can see large temperature drops in the stirred drinks when the ice is dropped (denoted by “ice” in the chart).  This is because the ice is actually hitting the thermocouple.  The temperature rises sharply when the drink is actually stirred (denoted by “st” in the chart).  The beginning of shaking is denoted by “sh.” The temperature swings are large in the shaken drink because the drink and ice are sloshed on and off the thermocouple.  Equal weights of uncracked Kold Draft ice cubes at 0°C  were used for all three drinks.  The initial volume and temperature of the drinks was identical. Notice how fast the shaking chills. The drink hits 0°C in under 10 seconds and has plateaued at -7°C in less than 17 seconds. Fast stirring gets the drink below 0°C in about 45 seconds and hits -3°C in about 1 minute 45 seconds.  The slow stirring takes almost a minute and 15 seconds to get to 0°C. How you stir makes a difference.

Here is a comparison of stirring using three different sizes of ice all at 0°C:

Stirring with different sizes of ice.

For scale, the “medium” sized cubes are the standard cubes produce by my home fridge’s ice cube maker.  All of the pictures are to scale. The big ice is really bad at chilling quickly. The small ice gets the drink below 0°C in a snappy 20 seconds –the big ice takes well over a minute. Notice that the medium ice is only about 20 seconds behind the small ice in getting to 0°C, but 2 minutes behind the small ice in reaching a -5°C plateau. It is more difficult for larger ice to chill those last couple of degrees. The big ice plateaus in a whopping 220 seconds at about -4°C.  Presumably, the length of time I had to stir and the extra energy from stirring so long is what prevented me from reaching -5°C like the other two drinks. To demonstrate that small ice chills more effectively, Ryan Fitzgerald, from Beretta in San Francisco, volunteered to stir a drink with very finely crushed ice during our seminar at Tales of the Cocktail. We spun the ice in a salad spinner to make sure it was “dry.” The tiny ice was so efficient that it chilled as fast as shaking.  His drink made it to -5°C in under 10 seconds and went all the way to -7°C in under 15.  Unfortunately, we all decided that his drink was too diluted.  All that extra chilling came at the expense of too much dilution. It would have been fine for a shaken drink, but not for a stirred one.

In light of the above chart, the common bar practice of cracking large ice cubes with the back of a spoon for stirred cocktails makes a lot of sense.  Un-cracked big ice is too inefficient at chilling; but smaller, more efficient ice might be carrying a lot of water on its surface. Cracking a big cube increases your surface area without increasing the amount of surface water.

The upshot? In stirring, the type of ice you use makes a big difference.

Two Visual Proofs of the Fundamental Law:

Proof 1: If you stir two drinks with different size ice cubes, but pour them out when they reach the same temperature, they will have the same dilution even though they were stirred for very different lengths of time.  The drinks will be identical!

If the temperature is the same the dilution is the same too!

I pulled the drinks when they reached -0.6°C.  Notice this temperature is a far cry from the -5°C plateau temperature I could have achieved by stirring for a long, long time, but stirred drinks are never stirred long enough to reach the plateau.   –0.6°C is much more realistic in the real world.

Proof 2: Whether you start stirring right away, or dump ice into a drink and let it sit for a minute before stirring,  the drinks will end up about the same. Just throwing ice into a drink doesn’t chill it very much.  Because it doesn’t chill very much, it doesn’t dilute very much.

Letting ice sit in a drink: We added Kold-Draft ice to a a room temperature drink and let it sit for one minute. That is the blue curve. At the end of one minute we added Kold-Draft ice to the drink represented in red (same volume of liquor and ice as in the blue curve) and began stirring both simultaneously. The large instantaneous drop in temperature of the blue curve prior to stirring is ice actually touching the thermocouple. As stirring commences, the temperature rapidly rises to show the true temperature of the drink.

This fact really surprised me. I had assumed that allowing ice to sit in a drink for a minute without stirring would over-dilute the drinks, but both drinks had nearly identical weights when they were finished.  You can’t get around physics.

Part 2 coming soon.

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An Update

September 1st, 2010 · Uncategorized

by Nastassia Lopez

Dave holding up traffic on Grand Street, as he pushes our new vacuum machine home.

A quick update on what’s happening around the lab (and apologies for the dearth of posts) —

Dave is currently putting the finishing touches on his Cocktail Stirring piece.

Interns have been crisping up beaver tails, playing with minerals, and working on new infusion techniques.

The New Yorker’s Michael Schulman talked to Dave last week about the recent egg recalls and salmonella outbreak (read the article here).

And our friend Mark Ladner, chef at Del Posto, graciously donated his enormous Ultravac 500 vacuum machine to the Cooking Issues team. Dave pushed it 2 miles along city streets from the restaurant to the lab today. Thanks Mark!

Many more posts to come. As always, thanks for reading.

-The Cooking Issues Team

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Cooking Issues Radio Live, Tuesday

August 23rd, 2010 · Uncategorized

Cooking Issues will be broadcasting live on the Heritage Radio Network tomorrow (Tuesday) from noon to 12:45 EST.  No special guests; just Dave answering all of your cooking issues via phone and/or email.

Give him a call at the Heritage studio at 718-497-2128 or email Nastassia at lopez.nastassia@gmail.com and we’ll answer as many questions as we can.

Thanks for listening!

The Cooking Issues Team

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