Cooking Issues

The International Culinary Center's Tech 'N Stuff Blog

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Skåls of the Week, 7.27.2009

July 27th, 2009 · skoal

(Hey, what is this Skål Project anyway?)

Good things come in threes…  For your skål viewing pleasure, here are some sets of three skåls:

Three photos of two brothers:

Matt and Ted Lee. Southern food experts, cookbook authors, magazine and newspaper writers.  Lovers of boiled peanuts.  Rarely seen apart.  Which is Matt and which is Ted?

Matt and Ted Lee. Southern food experts, cookbook authors, magazine and newspaper writers. Lovers of boiled peanuts. Rarely seen apart. Which is Matt and which is Ted?

Matt Lee.  This one is Matt.

Matt Lee. This one is Matt.

Ted Lee. This one's Ted.

Ted Lee. This one's Ted.

Three old-school 4 star French chefs:

Andre Soltner. 4 star chef. The Amazin Alsatian. Formerly of Lutece --the greatest restaurant in the US for decades. FCI Dean of Classic Studies. Took a vacation never.

Andre Soltner. 4 star chef. The Amazin Alsatian. Formerly of Lutece --the greatest restaurant in the US for decades. FCI Dean of Classic Studies. Took a vacation never.

Alain Sailhac. 4 star chef. Formerly of Le Cynge and Le Cirque. Dean Emeritus at the FCI. As real as it gets.

Alain Sailhac. 4 star chef. Formerly of Le Cynge and Le Cirque. Dean Emeritus at the FCI. As real as it gets.

Christian Delouvrier. 4 star chef, formerly of Lespinasse. Real French dude.

Christian Delouvrier. 4 star chef, formerly of Lespinasse. Real French dude.

Two Bloggers and a Rock and Roll Manager makes three:

Shoshana Sakolsky. Foodie Femme blogger.  Loves cocktails and science.  What's not to like?

Shoshana Sakolsky. Foodie Femme blogger. Loves cocktails and science. What's not to like?

Tam Ngo. Writes for Serious Eats (is also a lawyer). Lover of architecture, design and food. A mean photographer.

Tam Ngo. Writes for Serious Eats (is also a lawyer). Lover of architecture, design and food. A mean photographer.

Angus Vail. Manager for Kiss. Formerly Managed INXS. Kiwi. Food Lover.

Angus Vail. Manager for Kiss. Formerly Managed INXS. Kiwi. Food Lover.

Shoshana Sakolsky, Angus Vail, Tam Ngo

Shoshana Sakolsky, Angus Vail, Tam Ngo

And three ballet dancers!

Allegra Kent. Badass ballet dancer, muse of Balanchine, author of "Once a Dancer."

Allegra Kent. Badass ballet dancer, muse of Balanchine, author of "Once a Dancer."

Jacques D'Amboise, American ballet dancer and choreographer. Balanchine thought he was pretty cool and so do we.

Jacques D'Amboise, American ballet dancer and choreographer. Balanchine thought he was pretty cool and so do we.

Nina Brickman, ballet dancer, writer, mother of Sophie.

Nina Brickman, ballet dancer, writer, mother of Sophie.

 

Finally, we’d like to introduce you to three more members of our Cooking Issues family:

Raina Bien, FCI Marketing, one of the founders of Cooking Issues, tortured by Dave on an almost daily basis

Raina Bien, FCI Marketing, one of the founders of Cooking Issues, tortured by Dave on an almost daily basis

Travis Huggett, original Skål Project Photography Consultant & Skål Party Photographer, both Cooking Issues family and actual family - he's Dave's brother-in-law

Travis Huggett, original Skål Project Photography Consultant & Skål Party Photographer, both Cooking Issues family and actual family - he's Dave's brother-in-law

James Carpenter. The man behind the Cooking Issues cartoons. Dave's cousin. Lover of learning and vegetables.

James Carpenter. The man behind the Cooking Issues cartoons. Dave's cousin. Lover of learning and vegetables.

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Tales of The Cocktail: Science of Shaking II

July 24th, 2009 · cocktails

posted by Dave Arnold

As I mentioned in my last post: Last week I participated in a seminar at Tales of the Cocktail entitled The Science of Shaking. The panel was put together by moderator Eben Klemm (head of bar programs for the B. R. Guest restaurant empire, well-known innovative cocktail guy, and former biologist) with Alex Day (famed bartender from Death & Company and Franklin Bar) and myself as panelists.   Yesterday, we went over some basic cocktail science. Today we are talking simple results.

Dave, Eben, and a lot of Montezuma.  Alex Day photographing

Dave, Eben, and a lot of Montezuma. Alex Day photographing.

Question
When it comes to determining the final temperature and dilution of a shaken drink, does the type of ice in the shaker or the shaking style really matter?

Short Answer
No (within limits).

Important Note
We did not address drink texture in any way.  We first wanted to understand temperature and dilution.  Texture is vitally important. We hope to address that in the future.

Assumptions

  • Bar ice is 0° Celsius  (it isn’t stored in a freezer).  This is important.  If your ice is in the freezer, it can chill your drink before it starts to melt.  The ice will lower the temperature of your drink while getting warmer till it hits 0° C.  After the ice gets to 0° C, it doesn’t get any warmer.  ALL FURTHER CHILLING IS DONE BY MELTING ALONE.  In a bar situation, all chilling is done by melting.  There is no chilling without dilution.
  • You use “enough” ice.  We did initial experiments that showed that using too little ice results in poor chilling and greater dilution.  The benefit of adding more ice plateaus at a certain point so that it neither helps nor hurts the temperature or dilution.  I don’t have exact numbers for the plateau point (I lost my old data cause I’m a jerk), but using Kold-Draft ice, Eben and Alex shook a 100 ml gimlet with one cube, two cubes, three cubes, and up. They were able to keep getting better results up to at least 5 cubes.
  • You don’t use ice so broken down that it carries a huge amount of water with it.  The volume of an ice cube goes up as the third power of its size, but the surface area goes up as the square of the size.  Small ice cubes, therefore, have a larger surface area per gram than large ice cubes.  Since water resides at the surface of wet ice, immense amounts of surface area will unfairly add to dilution. 
  • You shake “enough.” Putting ice in the drink and walking away doesn’t constitute shaking.  You need enough agitation to get fresh drink in contact with the ice.  It doesn’t take a whole hell of a lot, as we shall see.

What We Did

  • I made some temperature recording shakers by soldering together some type K thermocouple wire, lightly coating the end with heat conductive epoxy (to prevent wicking into the thermocouple insulation), drilling holes into some cocktail shakers, and sealing the thermocouples inside with some steel-reinforced epoxy.  These were wired into a Measurement Computing 8 channel thermocouple receiver attached to my computer.
  • Type K thermocouple in the can

    Type K thermocouple in the can

  • We took a whole bunch of Montezuma Tequila and Calypso white rum and verified their alcohol content with a refractometer calibrated for ABV (alcohol by volume).  All the bottles measured 38% ABV instead of the advertised 40%.  We then cracked open some liquor that cost more than five bucks a bottle and it also registered 38, so we learned that Montezuma wasn’t ripping us off. Our refractometer was a bit off. 
  • We put all the liquor in a controlled water bath set at 75° F.  This was our “room temperature.”
  • We put a bunch of Kold-Draft ice and a bunch of small ice (made by our machine) into a Randell FX adjustable refrigerated drawer set to 0° C and let it equilibrate for 2 hours.  The side of a cube of Kold-Draft measures 1.25 inches across.  Many bartenders prefer it because the say it dilutes drinks less.  Some people also think it is somehow “colder.” Our small cubes measured .75 inches across a side but had a large simple which increases its surface to volume ratio significantly.

 

Kold-Draft ice vs standard ice

Kold-Draft ice vs standard ice

  • For every shake we weighed out similar quantities of ice, recorded the weights, and shook with 100 ml of room temp liquor (deviations of weight in ice are presented at the bottom of the post).
  • After every shake we strained the drinks into a fresh room temperature Dixie cup and measured its temperature with a calibrated thermocouple probe (the straining involved some snaps of the wrist to ensure we got all the drink out).
  • After the temperature was taken, the drink was poured into a labeled plastic bag sealed and thrown into a 75° F water bath.  The residual ice was also bagged and thrown into the water bath.
  • Bags O Cocktail

    Bags O Cocktail

  • After the samples reached room temperature, they were weighed and alcohol level was checked with the refractometer.
  •  

    The full test rig

    The full test rig

     

Notes: Yes, we corrected for the differences between weight and volume, and alcohol by volume and alcohol by weight in our calculations. No, there was no sugar or anything else in the liquor to throw off the refractomer readings.

First Experiment
Does type of ice or shaking style affect how cold a drink is or how fast it gets cold?  No.

Shakegraph2

The shaky lines are the actual bits of data from the thermocouple.  They go up and down as the drink was shaken.  The smooth lines are Excel’s 6th order polynomial curve-fit to the thermocouple data (whoa). 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 type of ice.  Also notice that the smaller ice is marginally faster than the Kold-Draft, but not by much (that makes sense because it has more surface area).  In fact, with the exception of Alex’s first shake (which was the first shake of the day so it might be an anomaly), all the shakes had almost leveled out by 12 seconds.  After that we only gained a degree or two of cooling.  A degree ain’t no big deal.  So much for big ice being “colder.” If anything, the reverse is true.  So much for needing to shake really hard.  You just need to shake “hard enough.”  We don’t know what the minimum “hard enough” is, but we know that a normal bartender’s shake is hard enough.  Speaking of shaking hard…

Second Experiment
Does shaking significantly raise the temperature of the drink due to friction? No.

We made “ice cubes” that were exactly the size of Kold-Draft cubes out of a 3% low acyl gellan/water gel.  3% gellan is pretty hard, but the cubes should act like ice cubes in terms of friction.  We brought the warm-draft cubes up to room temperature in our water bath and shook as usual.

"Warm_Draft" cubes, blocks of 3% low acyl gellan gel, next to Kold-Draft cubes

"Warm-Draft" cubes, blocks of 3% low acyl gellan gel, next to Kold-Draft cubes

WarmDraft

Eben did a normal shake—for 60 full seconds! I went one better and did the crazy monkey shake again (tiring). Note that even with all that shaking, the temperature of our 100 ml drink never rose even a full 2 degrees.  That kind of temperature rise would be counteracted by less than 2 grams of ice melting.  We found the friction effect insignificant.

Third experiment
Does chilling the shaker and the type of shaker matter? Yes, a little bit.

Alex Day shook some drinks with Kold-Draft cubes using different shaker configurations.

ShakerType

Glass fared worse than metal unless it was chilled with liquid nitrogen (which is cheating). Metal reached a lower final temp than glass did.  In fact, room temp metal chilled slower than a chilled glass but got to a lower temperature.  Presumably this is because the glass absorbs more heat. I don’t know why the room temperature glass curve is so steep at the outset. Fluke?

Finally, the most important experiment
Does the type of ice affect the final temperature, the final ABV, or the final dilution of the drink? No!!!

Alex Day did all the shaking on this one.  He took Kold-Draft ice and shook it with 100 ml of Montezuma for 3, 5, 8, 9.5, 12, 13.5, 20, and 40 seconds, then took crappy ice and shook it with 100 ml of Montezuma for 3, 5, 8, 9.5, 12, 13.5, 20, and 40 seconds.  Those numbers were chosen because they were benchmarks for temperatures and times we had achieved in our prior shaking tests.   When we analyzed the results, we noticed that the final weights of products we ended up with was lower than the starting weight in every shake.  Our first reaction was WTF? Our explanation is that there is a certain “angel’s share” to cocktail making. You lose some while straining, you lose some while shaking, and so on. Here is how much was lost from each sample:

WTF! angel's share for cocktails?

WTF! angel's share for cocktails?

Because of the loss, when determining dilution we used both ABV and the amount of ice we had melted into the drinks as a guide. Here are the results of the tests:

dilutiontemp

Wow.  The curves for standard and Kold-Draft cubes are almost the same! What’s really amazing is that after about 10-12 seconds you get less than 2 degrees extra cooling and between 20 and 40 seconds of constant shaking you only lose 1-1.5% ABV.  We thought those results were pretty amazing. Between 20 and 40 seconds, we had only melted 20 grams more of ice.  These numbers are in line with strict calculations: 100 ml 40 ABV booze + 70 ml water = 170 ml at 23.5 ABV, about (we got 21), 100 ml 40 ABV booze + 90 ml water = 190 ml at 21 ABV (we got 19.5-20). Remember, however, that our refractometer was reading a bit low.

What does this all mean? In terms of temperature and dilution, your style of shaking and the ice you use probably doesn’t matter.  The length of time you shake probably doesn’t matter.  All of these are probably vitally important to the texture and look of the drink. Eben put it best when he said that these results should set you free to develop your own style of shaking because you no longer need to worry about time and temperature. 

One last thought:  We all know that small ice dilutes more than big ice in the glass (or in the shaker if you let it sit there long enough.  How do we reconcile that knowledge with the above data? Simple. As the drink sits, it absorbs heat from the surroundings, melting the ice.  In a non-agitated situation (like sitting on the bar), big pieces of ice, with its large volume and low surface, will melt slower and dilute your drink less. 

deviations in ice weight for different shakes/different ice graph

deviations in ice weight for different shakes/different ice graph

deviations in ice weight for dilution/temp/ice graph

deviations in ice weight for dilution/temp/ice graph

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Cocktails: The Science of Shaking

July 22nd, 2009 · cocktails

Posted by Dave Arnold

Last week I participated in a seminar at Tales of the Cocktail entitled, “The Science of Shaking.” The panel was put together by moderator Eben Klemm (head of bar programs for the B. R. Guest restaurant empire, well-known innovative cocktail guy, and former biologist) with Alex Day (famed bartender from Death & Company and Franklin Bar) and myself as panelists.

Before I post the results of the seminar, I wanted to do a short post on some basic cocktail science.  I am not a scientist, so please feel free to correct me.

Question: If ice melts at 0° Celsius, and I start with 0° ice, how is it possible that shaken drinks can get down to minus 7° Celsius?

Plain ice at 0C.  Shake it with booze. Now it's -8.8C! (It's lower than -7C cause I used high-proof booze, but that's another post)

Plain ice at 0C. Shake it with booze. Now it's -8.8C! (It's lower than -7C cause I used high-proof booze, but that's another post)

Answer: First of all, yes, shaken drinks can get down to minus 7° just by shaking with ice.  

Well, we all know that alcohol freezes at a much lower temperature than water, but that still doesn’t answer the question: how can ice make something colder than 0°?

This question can be approached  several ways (colligative properties, vapor pressure, etc.), but I think the most fundamental way is to see the problem as a balance of changes in enthalpy and entropy. In other words, molecules are lazy but they also like to be free.

In any reaction, a change in enthalpy is a measure of the heat absorbed or released during that reaction (assuming a constant pressure, yadda yadda).  In general, all things being equal, things want to give off heat.  By giving off heat they have a lower internal energy. Things want to go to a lower energy state.  Things are lazy.  It takes energy to break ice molecules free of the crystal lattice, so there is less energy stored in an ice cube than in water at the same temperature and pressure (cause I had to dump in heat to make it into liquid water).  This heat that has to be added to ice to make water is called the enthalpy of fusion (or the heat of fusion).  The heat of fusion of water is about 80 calories per gram, meaning that the heat required to melt one gram of ice is sufficient to heat one gram of water all the way from 0° to 80° C!  Remember: melting ice requires heat (the heat comes from your drink so your drink gets colder). Making ice gives off heat, so enthalpy favors water turning to ice.

Entropyis a different story. Entropy is often described as a measure of disorder.  Greater entropy equals greater disorder.  A better way to think about it is as a measure of how many different states something can be in (scientists call these microstates).  Things want to increase in entropy. Things want to maximize the number of available microstates and then commence to occupy those microstates in a random way. Things want to be free. At any given temperature, there are more positions, speeds, etc.—microstates—in a liquid than in a solid. Water molecules, for instance, are free to spin around and find new neighbors, etc.  Ice molecules are locked in a crystal. Being a solid is more constrained than being a liquid, so entropy favors ice melting into water.

So who wins, enthalpy or entropy? It depends on temperature.  As the temperature goes up, entropy tends to dominate and ice melts. As the temperature goes down, the heat of fusion tends to dominate and water freezes. At high temperatures, entropy wins because there are more microstates available to the molecules in the liquid water than at lower temperatures (cause they are moving around more). Thus, there is more of an entropy win by turning to a liquid than at lower temperatures.  The freezing point of water (0° C) is the point at which the entropy gain from ice  melting to water is exactly balanced by the amount of heat given off by water freezing into ice.  Water molecules are constantly freezing into ice and melting into water at the same rate—they are in equilibrium. If you lower the temperature, the entropy gain becomes puny and water wants to freeze.  If you raise the temperature, the entropy win outstrips the enthalpy part and the ice wants to melt. Got it?

What happens when you add alcohol? For the purposes of this discussion, let’s assume that the ice crystals remain pure water (that’s pretty true). Ok. We are at 0° C, we have ice and water at equilibrium, and we add alcohol into the liquid water.  The heat given off by water molecules freezing into ice is the same as it was before, because the ice hasn’t changed; but the entropy win of ice melting into the water/alcohol mix has gone up.  Ice melting into the water/alcohol mix has more microstates available, more ways of being arranged than were available in the pure water, because there are more different ways of arranging x water molecules and y alcohol molecules than there are of arranging x+y water molecules. So what happens? The entropy gain of melting wins and the ice starts to melt.  Melting ice absorbs heat.  The only place the heat can come from is from the ice and water/alcohol mixture (oh yeah, I forgot to mention I am assuming a closed system), so the whole shebang cools down below 0°.

What’s really cool is that as the ice melts, the solution gets more diluted, which reduces the magnitude of the entropy win at the same time as the temperature goes down.  This happens until a new equilibrium is reached, when the entropy and enthalpy become balanced again—that is the new freezing point of your drink.  The theory is pretty straightforward but figuring out the final temperature and dilution of a drink from first principles is well, well beyond my ability.  I encourage you to try and tell us how.  One note before you try, though: I’d say it’s probably a lot harder than you think. Even assuming a closed system (false), and no energy input from shaking (false), and no problems with surface area and speed of agitation and quantity of ice vs mixture (somewhat false), it’s a hard problem to solve exactly.

Next installation: Tales of the Cocktail Seminar: The Science of Shaking, does type of ice matter?

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Oh Lord, won't you buy me a new centrifuge

July 21st, 2009 · centrifuge

Posted by Mindy Lvoff

While I was in LA a few weeks ago, I checked in with Dave by phone and he asked how close I was to San Jose…  It turns out that he had purchased yet another centrifuge and wondered whether or not I wanted to pick it up and fly it home.  No, I didn’t, and when it finally did arrive, I realized that he had *most likely* been joking.  His new, Jouan centrifuge is “bench top,” meaning it can sit on a table (or bench), but it still weighs over 150 lbs.

Where did he buy the new, used centrifuge (‘fuge) from?  Ebay, of course, and he purchased it for less than it cost to ship: $199 for the ‘fuge, $250 to ship it to NYC.  The next, cheapest ‘fuge listed is a little over $700.  Dave attributes the discounted price to bad spelling – apparently it was listed as a centrOfuge, not a centrifuge.  Being the savvy Ebay buyer that he is, Dave had been betting on just such an error on the seller’s part and was searching for all variations of the word “centrifuge.”  You see, kids?  Spelling IS important.  Or at least knowing how to use spellcheck is…

Our *new* Jouan Centrifuge arrives (not pictured: Ecstatic Dave)

Our *new* Jouan Centrifuge arrives (not pictured: Ecstatic Dave)

Why yet another centrifuge?  Dave wanted a centrifuge that could handle larger volumes of juice clarification – the Jouan does about 4,000 g’s and can handle up to 3 litres of liquid while the dangerfuge only handles 400 ml at most and the Unilever-fuge can only do about 1.5 litres.  Of course, that was  before Dave broke the agar clarification technique.  Now that we use the agar clarification method, using the Jouan for juice clarification isn’t really efficient.  However, we are able to do larger quantities of our nut oils, not to mention the other applications that we will surely find the new ‘fuge useful for.

The Jouan ‘fuge also speeds up and slows down a lot faster than our old ‘fuges.  For example, the dangerfuge never slowed down and Dave would sometimes manually stop it by holding a piece of rubber against it until the friction finally stopped its rotation.  The Unilever-fuge took at least 5 minutes, sometimes more, to come to a full and complete stop.  The Jouan usually stops spinning in under a minute-twenty.

There’s also the added safety benefit: the Jouan is the safest of all our ‘fuges. The dangerfuge was aptly name because it’s potentially deadly and the Unilever ‘fuge allows you to open the chamber while the rotor is still spinning, if you’re dumb enough to try.  The Jouan adds that extra layer of idiot-proofing by locking the chamber anytime the rotor is in motion.  Unfortunately, the chamber isn’t refrigerated, though, so Dave needs to figure out an alternative way to chill it at some point.  The chamber isn’t air-tight and allows for ventilation, meaning that we may be able turn to Liquid Nitrogen in the future as a potential chilling method.  Stay tuned.

Some people collect stamps... from left to right: dangerfuge, Unilever's centrifuge, our latest Jouan centrifuge

Some people collect stamps... from left to right: dangerfuge, Unilever's centrifuge, our latest Jouan centrifuge

Before we even used our centrifuge, however, we needed to sterilize it since it was most-likely used to spin blood in its past life. The best way to sanitize the Jouan’s buckets would have been to use an autoclave, which sterilizes medical equipment by using high-pressure steam. Since we didn’t have ready access to an autoclave, Dave (as usual) MacGyvered an alternative: he pressure-cooked the Jouan’s buckets at 15 psi for about 2 hours after soaking them in a concentrated bleach solution overnight. We (read: interns) also cleaned the interior and exterior of the machine with a concentrated bleach solution and let it air-dry, repeating this process several times.

Step 1: Sterilizing the Jouan centrifuge's buckets in a concentrated bleach solution overnight

Step 1: Sterilizing the Jouan centrifuge's buckets in a concentrated bleach solution overnight

Step 2: Pressure-cooking Jouan buckets, simulating autoclave steam-sterilization

Step 2: Pressure-cooking Jouan buckets, simulating autoclave steam-sterilization

Intern sterilizing Jouan centrifuge with concentrated bleach solution

Intern sterilizing Jouan centrifuge with concentrated bleach solution

The Jouan contains 4 swinging buckets that load in upright and then spin out so that they are horizontal while spinning.  While the Jouan both speeds up and slows down much faster than either of our previous ‘fuges, nobody (read: interns) was happy about the idea of a bucket potentially dumping liquid back into the chamber.  Dave came up with yet another solution: vacuum bags.  Using a plastic sealer that we use to double seal our vacuum bags (as the factory seal isn’t really a seal at all so much as it’s a line of somewhat melted together plastic), he clamped the bottom corners of the vac bag so that the bottom of the bag is now flat with the original edge running down the flat bottom’s center.  The bag is then placed in the bucket, filled with nut or olive purée, etc. (Robo-couped and then Vita Prepped), and then the top of the bag is sealed (not vacuumed), meaning that the product is completely contained within the bag, never touching the sanitized buckets, and having no ability to shoot out of the bag and all over the inside of the centrifuge chamber.  No mess spinning.

Inside the Jouan Centrifuge - sterilized swinging bucket

Inside the Jouan Centrifuge - sterilized swinging bucket

As usual, we weigh whatever we are spinning to make sure that all buckets are within 2/10ths of a gram of each other.  Dave also purchased a Harvard Trip Balance that helps us do just this ($15 eBay), and it happens to be accurate to within 2/10ths of a gram.  Convenient.

Balancing nut purée

Balancing nut purées in house-made centrifuge bucket liners

Another added benefit of the Jouan’s swinging buckets is that it creates better stratification of the solids and liquids after spinning.  Before, the fixed, slanted cup-holders in our other ‘fuges meant that we would get angled layers.  The better stratification is particular fun when doing cured olive oils – we’re able to separate both a flavorful oil and a delicious olive brine from the cured olive purée.  The brine makes for a damn good dirty martini.

left to right: nut purée pre-spin and then nut oil sitting in a perfect layer on top of nut solids.

left to right: nut purée pre-spin and then nut oil sitting in a perfect layer on top of nut solids.

Dave has also found a curious phenomenon when spinning nut purées dosed with simple syrup: you’re able to pull a clearer, but less flavorful oil.  He’s not really sure why this happens yet – please let us know if you have any thoughts on why this occurs.  The nut solids that are separated from the oil also become denser, allowing us to mold them into little bricks which can be cut and even grated.

centrifuge-extracted nut oils: on the left, nut oil from sugar-dosed nut purée; on the right, our normal nut oil

centrifuge-extracted nut oils: on the left, nut oil from simple syrup-dosed nut purée; on the right, our normal nut oil

simple syrup-dosed nut solids can be shaped, cut, and even grated

simple syrup-dosed nut solids can be shaped, cut, and even grated

In Dave’s eyes, what really separates the Jouan from our other centrifuges is its lab-to-kitchen crossover potential.  Its size and relative-affordability mean that should we find more applications for food and centrifugation that warrant its purchase, chefs could easily add it to their kitchen equipment.  So far, we have spun: avocados (both puréed & whole for a laugh), tomato paste (which yields a minute quantity of the most intense-flavored tomato liquid in the world), pecans (with and without simple syrup), walnuts, pistachios, macadamia nuts, almonds, Marcona almonds, peanuts, and cured olives.

Here is our offer and request: since we already have the centrifuge, please share with us any spinning ideas and requests that you would like us to try.  Who knows, maybe the centrifuge will follow the path of the immersion circulator someday and find a new home in the restaurant kitchen.

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Skål Exchange Program

July 20th, 2009 · skoal

Posted by Mindy Lvoff

Our loyal reader and regular commenter, Patricio Wise, wanted to import our Skål Project to Mexico.  In order to truly uphold the spirit of the Skål Project, Patricio knew that your average, everyday bottle of Aquavit just would not do – he needed a bottle of Cooking Issues Aquavit.  Yet how would he persuade us to send him one?

The solution: an exchange program.  Patricio sent us a bottle of Tequila and requested that we send back a bottle of Aquavit.  Nils and Dave took it upon themselves to test the tequila to see if it was skål-worthy.  The results…

Skål, Patricio!  Muchas Gracias!

Skål, Patricio! Muchas Gracias!

Indeed, the tequila, and therefore Patricio, proved worthy:

Patricio Wise, Chef, Blogger, Mexican Skål Project Ambassador

Patricio Wise, Chef, Blogger, Mexican Skål Project Ambassador

For more about how he received and honored his bottle of Cooking Issues Aquavit, click here for the English translation (or here if you hablas español).

Skål to the world.

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Simple Agar Clarification vs Gelatin Clarification: Another Difference

July 17th, 2009 · Agar, Clarification

posted by Dave Arnold

One difference between simple agar clarification and gelatin clarification is that gelatin clarification has the ability to clarify and concentrate at the same time while simple agar clarification does not.

Separating the juice over the course of the clarification to measure changes in taste.

Separating the juice over the course of the clarification to measure changes in taste.

For those who don’t know agar clarification see here. For those who don’t know how to clarify liquids with gelatin, here it is: hydrate approximately5 grams of gelatin into 1 kilo of liquid, freeze the liquid solid, and slowly thaw it over cheesecloth in a refrigerator. 

One of the interesting properties of gelatin clarification is that the first liquid that drips out of the frozen block is extremely rich in sugar, acid, color, etc.  It is concentrated.  As the block continues to thaw, the liquid becomes more and more watery.  This process allows for an easy way to concentrate flavor without using heat, and to adjust the strength of the clarified product (at the expense of yield) by terminating the clarification process whenever desired. 

Simple agar clarification doesn’t work this way.  The new clarification technique is simple forced syneresis (the leaking of fluid from a gel), and doesn’t preferentially drip sugar, acid, and flavor the way an ice cube does.  The agar does hold on to some water (that’s what a hydrocolloid does), so the clarified product is more concentrated than the original; but the product’s concentration doesn’t change over the course of clarification the way it does with gelatin. 

To prove it we hydrated 2 grams of agar in a kilo of orange juice, set it, broke it up with a whisk, and drained the clarified juice in 45 gram increments in mise en place cups and measured the Brix of each sample with a refractometer.  We also tasted the samples to see if there were any appreciable difference.

Results: The original Brix of the juice was 12.2.  Brix of the samples fluctuated between 12.9 and 13.1 (not much of a difference).  We noted the moments we twisted extra hard or re-stirred the agar, but that didn’t make a difference either.  The samples all tasted about the same.  Juice from the end of the run has a slight haze (from pressing really hard on the agar and extruding some through the cheesecloth). Finally, they all tasted about the same.  Here is a graph:

brixchart

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Boozehound Alert: Agar Alcohol Clarification Plus Some Thoughts.

July 14th, 2009 · Agar, Clarification, cocktails

posted by Dave Arnold

High alcohol fluids can’t normally be clarified with gelatin because they can’t normally be adequately frozen. A couple of years ago, the guys over at Tailor at the time (Sam Mason and Fran Derby) had the idea to freeze the gelatin laced liquor with LN; when it thawed, it clarified. Brilliant. They never demoed and took credit for the idea, so I felt uncomfortable using it, but now there is a new technique.

When I was working with spinning unfrozen agar gels in the centrifuge to clarify them, I made that technique work with liquor.  I was going to post on that technique but that technique has also been superseded—in less than a month!

Simple agar clarification gets the job done.

The look is much brighter than vacuum infused strawberry gin, and I like the taste a lot more; which I didn’t think was possible.

Clarified Strawberry Gin

Clarified Strawberry Gin

The recipe and procedure (this recipe size is too small, you will want to triple it to increase yield):

100 grams of strawberry purée (blend strawberries, pass through a chinois)

300 grams Tanqueray Gin (47.3% abv) room temperature.

1 gram Telephone brand agar (o.25% of total weight of gin and strawberry)

Whisk the agar into cold purée the disperse the agar. Heat the purée while stirring till it comes to a rolling boil.  Continue a soft boil for a couple of minutes (you can add some water to make up for evaporation) to hydrate the agar.  Turn off heat and while vigorously whisking, slowly add the gin to the strawberry agar mixture. If the temperature of the mix falls below 35° C while you are mixing, you might get some pre-gelling and ruin the gel. Put the mix in a half hotel pan over an ice bath to set.

 

Breaking the Strawberry Gin Gel

Breaking the Strawberry Gin Gel

After the gel is set, break it up with a whisk.

Gin Squeezins

Gin Squeezins

Dump the broken gel into a cheesecloth and squeeze. Occasionally open up the cheesecloth and stir the mixture to increase flow.  My yield was only 200 ml, but I lost a lot to the cheesecloth, etc.  Larger batches would yield much more.

Notes:

  • I used a little more agar here than I normally do cause the alcohol messes with the gel a bit. 
  • The finished mix of strawberry and gin is about 35% abv.  This is the sticking point of agar and liquor. I doubt the proof could be pushed much further north, but I’d be super-pleased to be proved wrong.
  • Don’t attempt to boil the gin.  The temperature will be too low to hydrate the agar plus it will certainly catch fire.

This technique can be used to clarify any low- to medium-proof spirit mix, bitters, etc.

I couldn’t really measure the proof of the finished drink because the strawberry messes with both the density and the refractive index of the product, so I can’t easily use my hydrometer or my refractometer.  For the record the drink tasted fairly full strength, like the average vacuum infused gin, a little under 40 abv.

More thoughts:

The cheesecloth should be replaced with something tougher, more even, and less absorbent—like a superbag.  My feeling is that a superbag is really an overpriced paint straining bag (try www.thecarycompany.com/containers/ez-strainers.html with many different mesh sizes, or www.mcmaster.com/#95495t42/=2r0b3p which is 530 microns).  Since I have never used a real superbag,  someone please tell me if I am wrong

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Agar Clarification Made Stupid-Simple: Best Technique Yet

July 14th, 2009 · Agar, Clarification

posted by Dave Arnold

Upshot:

Anyone with a packet of agar and a whisk can clarify fragile fresh juices, or anything else for that matter, in under an hour with zero pieces of special equipment. The yield on the technique is high—as good as gelatin clarification. Read more for details.

Clarified Orange Juice

Clarified Orange Juice

Long Story:

Yesterday I wrote a post about a new clarification technique posted by Ideas in Food where agar gels are put in vacuum bags to get clarified liquids out of them. They call the technique “compression clarification.” I stayed up till 1am or so getting the post out, vegged for a bit, and tried to go to bed. I could not sleep. Something was gnawing at me. I kept thinking about how much harder the Ideas in Food block of agar looked in the bag as opposed to mine. Mine was so soft it broke just by moving it and was quite soupy in the bag. I used the same 2 grams of Telephone brand Agar per kilo of product that I always use, which is just barely gelled. I wondered why theirs looked so much harder.

Something else bothered me: I don’t like the term compression the way it is used by chefs. I don’t like it for the same reason I don’t like the Under Pressure title of Thomas Keller’s sous-vide book. The terms are misleading (unless Under Pressure is a pun on under-pressure, meaning less pressure than normal, in which case the title is hilarious). With the exception of items that contain air, foods in vacuum bags aren’t being compressed (except at the edge where the bag tries to press together). Instead, vacuum bags press against your food with exactly the same force that air was pressing against it before. Only if your food has a lot of air holes that get evacuated during the vacuum cycle will it feel a lot of pressure. Air holes will feel a force of about 15 psi because you have removed that much pressure from them, sealed them inside the bag and then brought the force of the atmosphere back to bear on them. Even flash infusion isn’t compression, it is injection. Many things with air in them, a block of aluminum foam for example, won’t compress in a vacuum bag either (although it will be under compression), because they are too strong.

Agar gels, if well made, don’t have air. They are essentially liquids with some solids mixed in, and are uncompressible.

Also, I had been using physical techniques to clarify with agar for quite some time: see my experiments with spin gel clarification. Something I had forgotten was that I could get clarified juice out of those gels even after they were broken. I had dumped out one of the gels and spun it again, and even though the gel had been broken, I got more clarified juice. The reason I didn’t develop that technique further was it required a centrifuge.

All of a sudden it hit me like a ton of bricks: not only do you not need the centrifuge, you don’t need the bag and you don’t need the vacuum. All the bag was doing was slapping the agar silly. I could do that with a whisk! It was 3am. I jumped out of bed trying not to wake my wife, got dressed, jumped on my bike and dashed off to The FCI to get agar, OJ, and cheesecloth. I wanted lime juice, but at 0 dark 30 in the morning I didn’t want to squeeze any limes. OJ was fine.

Well, it worked like a champ. I made it home bout 3:45, clarified the juice, shot the pictures, and was in bed by 5. I slept like a baby—till 7 when I had to get up with the kids.

The advantages of this technique are:

  • It is fast so fragile juices like lime can be clarified
  • You need no special equipment
  • It is vegetarian
  • It is foolproof
  • The results are clearer than gelatin for some products
  • You don’t tie up fridge space with hotel pans
  • You don’t tie up freezer space with hotel pans
  • Yield is high
  • Because there’s no freezing involved, you can clarify alcohol without liquid nitrogen (I’m letting the cat out of the bag—that was supposed to be my next post)

Caveats:

  • Agar needs to boil to hydrate. Don’t boil heat-sensitive juices like lime. Instead use 4 parts room temp (25°C) juice and hydrate in 1 part water. After the juice is added to the boiling agar-water mix (off the heat) the temperature will be perfect. If you are using refrigerated juice that can tolerate some heat, boil 1 part liquid with the agar and add in 2 parts refrigerated juice.
  • Use real cheesecloth. Don’t use the stuff from the supermarket with the picture of the turkey on the package. That stuff is ludicrous. I don’t know why they make it. If you can’t get real cheesecloth use muslin, a large cloth napkin, or a smooth-finished dish towel.

Instructions

Instructions1
1.) Measure out 500 grams cold OJ, 250 grams cold OJ, and 1.5 grams of Telephone brand Agar (0.2% of total juice weight). 2.) Whisk the agar into the 250 grams of cold juice to disperse the agar then heat to a boil while stirring and allow to simmer a couple of minutes to hydrate the agar. 3.) While briskly whisking the boiling-hot agar solution add the 500 grams of cold juice in a thin stream. Don’t allow the mix to drop below 35°C or pre-gelling could ruin your result. 4.) Put on an ice bath to set.

Instructions2
5.) Using a whisk, gently break up and stir the gel into agar “curds.” 6.) Dump the curds into a cheesecloth lined chinois. 7.) Lift and gently squeeze to drain. 8.) After a while you can dump the curds back into the bowl to break them up some more.

The Broken Agar "Curd"

The Broken Agar "Curd"

Instructions3
9.) Alternatively, you can just stir the curds in the cheesecloth to release more juice. 10.) Twisting the cloth presses juice out gently and quickly. Don’t twist too hard or you will extrude the agar through the cheesecloth. 11.) The clarified juice. 516.8 grams! And I started with unstrained juice! If there are any agar particles in the juice, filter it through a coffee filter. 12.) The leftovers. 87.7 grams. Yeah I know the numbers don’t add up to 750 grams.

That’s it.

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Major Clarification Breakthrough from Ideas in Food

July 14th, 2009 · Agar, Clarification

posted by Dave Arnold

Aki and Alex from Ideas in Food have hit on a major breakthrough on clarification: the use of a vacuum machine to get clarified liquid from agar gels. Occasionally, I see ideas so good I’m pissed I didn’t think of them myself. This is one of those. Everyone who reads our blog probably reads theirs but I figured this idea was important enough to post on anyway.

Regular gel clarification, whether by gelatin or agar, involves freezing a gel and slowly thawing it.  The freezing breaks the gel so that as it thaws, it weeps out clear liquid while holding back the cloudy parts.  This process takes time (a day or two).  In our post on spin gel clarification we described a technique for quickly clarifying liquids (lime juice) without freezing using agar and a centrifuge.  The problem with that technique is that it requires a centrifuge.  Alex and Aki simply put the gel in a vacuum bag to get the same result making the process much more widely available. 

With most products, the length of time it takes to clarify something isn’t much of a concern.  With a couple of products, time is crucial.  Anyone who knows us knows we love clarified lime juice.  Lime juice becomes an awful tasting mess by the time it freezes and thaws. The vacuum technique performed miraculously well on lime juice.  We took 589 grams of lime juice plus 161 grams of water and got a surprising 423 grams of clarified lime juice in under an hour (the water didn’t make the clarified juice taste watered down). Here is the procedure we used:

589 grams fresh room temperature lime juice (don’t worry about the particular amount, its just what we had)

161 grams cold water (again, the numbers aren’t important, just make sure the water weight is about one fourth the weight of the lime juice. We chose 161 grams  so the total weight of water plus lime juice would be 750 grams for ease of calculation)

1.5 grams Telephone brand Agar (0.2% of the total weight of lime juice plus water)

Whisk the agar into the cold water and then heat the water while stirring until it boils, then continue to simmer for several minutes to insure proper hydration of the agar. Turn the heat off and while vigorously whisking, slowly add the lime juice to the water.  This is the important step in the process.  If the lime juice itself is boiled with the agar it will taste bad.  If the temperature of the water-lime juice mixture drops below 35° Celsius while you are mixing, it can pre-gel and ruin your result.  That’s why we chose about 4 parts room temp juice (not cold juice) to one part boiling agar + water.  After the two liquids are mixed together, the temperature will be about 35-40° C.  Let the lime juice gel set in an ice bath.

Lime juice gelled with 0.2 percent agar

Lime juice gelled with 0.2 percent agar

Once the gel is completely set (it will be very soft and will break apart under its own weight), put it in a vacuum bag and seal it with as high a vacuum as you can muster. Without re-opening the bag, Apply the vacuum again till the bag inflates then release the vacuum. Do this a bunch of times (we did 6).

Lime juice gel in a vacuum bag

Lime juice gel in a vacuum bag

Pour the whole sloppy mess into a cheesecloth over a chinois. The clear lime juice will strain out. Don’t squeeze too hard or you will squeeze a whole bunch of agar into your juice. After a while you can throw the cheesecloth back into a vacuum bag and hit it with the vacuum a couple more times.

Squeezing out the juice

Squeezing out the juice

The lime juice you have will be perfectly clear, but will have some tiny bits of floating agar. Filter these bits out with  a coffee filter and you are done.

Clarified Lime Juice

Clarified Lime Juice

I like this technique so much I probably won’t use my centrifuge for gel clarification anymore (I’ll still use if for enzyme clarification, of course, because the yield is so high).

 I had a new spin-gel clarification technique I was going to post, but in light of this new technique, I’ll rework my idea and post tommorow.

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Delicious sinew

July 13th, 2009 · Sinew

Posted by Nils Noren

separating sinew and meatI was fortunate enough to have dinner at Masa, here in New York, the other night. And I was also very fortunate in not having to pick up the check (thank you so much, Christian and Andrea). Chef Masa and his team sure know how to put on a great show. We didn’t have one thing that I didn’t like—everything was spot on.

I know myself oh too well and knew I wasn’t going to be able remember all the dishes. So I actually wrote them down on one of my business cards. One of the skills that I have (I know it’s not that many) is that I can write really small and then actually be able to read it afterward.

First part of the menu, the writing is pretty small. Right? The rest of the menu is on the flip side.Second part of the menu, still pretty small
It came in real handy this time. One of the first dishes we had was toro tartar with caviar.  I know it’s nothing earth shattering, but it’s pretty darn tasty. Chef Masa brought out a big piece of tuna and started to separate the meat from the sinew. He put the sinew on the side and one of his chefs picked it up, and I assumed it was to throw it away. Wrong! When we got into the sushi portion of the meal, out of nowhere appeared the sinew that I thought had ended up in the garbage.  It was grilled and then served as a piece of sushi. I never had sinew on its own before (wait, that’s a lie, I think a had a couple of crappy tuna tartars with the sinew mixed in).  It was delicious.

So sitting in my office on a beautiful Saturday afternoon, I happen to take out that business card of mine with the menu on it. And just waiting for a reason to leave the office and head for the kitchen, I remembered the grilled tuna sinew sushi. Two minutes later I was in the storeroom here at FCI looking for tuna. And I was blessed: right there in the fish drawer was a five pound piece of tuna. It wasn’t as fatty as I wanted it to be, but I had to do it—I cut off the sinewy part of the piece and headed for the kitchen.

I started to separate the sinew from the meat. Then I took one piece of the sinew and put in a vacuum bag with some yuzu and soy sauce.

Tuna sinew in bag with yuzu and soy, and a wierd looking guy behind.

Tuna sinew in bag with yuzu and soy, and a weird looking guy behind.

I put it in the vacuum machine and sucked a 98.5% vacuum on it. I immediately opened the bag and dried off the piece. I didn’t have a grill going or the patience to wait for one to get hot, so I used a saute pan instead. I put some duck fat in the pan, got it smoking hot, and then put in both the piece of sinew that was marinated and another piece that hadn’t been marinated. I cooked them for about 45 seconds. They were both delicious, but the marinated one was by far the better one.

Marinated sinew to the right.

Marinated sinew to the right.

It tasted like beef, even though the tuna wasn’t fatty. It was a really good product—just imagine how much better it would have been with a fatty piece.

So there you have it. All these years I have been throwing away all these tuna sinews (I regret that). But no more of that; it will from now on be regarded with the respect it deserves. And it’s also the only way I will eat well done tuna.

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