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Sous-Vide and Low Temp Primer Part II: Cooking Without a Vacuum.

April 7th, 2010 · 44 Comments · low temperature cooking, sous vide, Uncategorized

posted by Dave Arnold

For part one of the primer, an introduction to low-temperature cooking and sous vide –including some funky charts– see here.

I got a bit long winded again.  I  intended to have Part II of this primer cover all forms of packing and preparing for low temperature cooking.  It was getting way too long – so here’s today’s installment.

II. Low Temperature Cooking Without a Vacuum.

… in which we’ll discuss preparing foods for low-temperature cooking without using a vacuum machine; we’ll look at zip-loc bags, plastic wrap, and cooking in oil/stock/humid air.

Before We Start: A Note from New York City:

New York City + No HACCP plan = no vacuum machines.

In New York City, a restaurant cannot use a vacuum machine without developing a HACCP plan.  HACCP (Hazard Analysis Critical Control Points) is a system designed to ensure food safety.  It was developed by large corporations who were making food for space missions –giving an astronaut food poisoning can be catastrophic. Creating your own HACCP plan (explained in the upcoming safety section of the primer), even if you don’t implement it fully, is a great way to help yourself ensure food safety. HACCP plans administered by the Board of Health, on the other hand, are a pain in the rear. They entail extra inspections, log books, lots of time, and possibly spending money on consultants. Look here for the Board of Health guidelines.  Low temperature techniques that do not require a vacuum machine have a major advantage for New Yorkers: no HACCP plan required. 

Even If You Don’t Cook in New York City:

While I love a commercial vacuum machine, about 90% of what a cook wants to accomplish with low temperature cooking can be achieved without a vacuum machine.  When Nils was at restaurant Aquavit he did a lot of low-temperature work with a circulator, but didn’t have a vacuum machine.  Back then restaurants weren’t required to have a HACCP plan;  he didn’t have a commerical vacuum because they cost too much.

Today many home cooks use the Food Saver vacuum for low temp.  I don’t use my Food Saver any more. I use Ziploc bags, without a vacuum.  I find Ziplocs easier than the Food Saver – I don’t have to hunt down the special bags, I can easily bag sauces (a pain with the Food Saver), I can bag hot foods (foods to be vacuumed need to be cold – more on that in the next primer installment).  My Food Saver has been relegated to potato-chip-bag-resealer.

To Review:  

Low temperature cooking is defined as any cooking procedure where the cooking temperature is at, or close, to the desired final internal temperature. There are two requirements for low-temperature cooking:

  • precise and accurate temperature control
  • a cooking medium which conducts heat more efficiently and accurately than dry air. Water and water vapor are typical; oil, stock, or any other liquid will work.

 
The Basics: To Pack or Not To Pack

There are two basic approaches to low temperature cooking:

  • Expose the food to the cooking environment – includes cooking in temperature controlled poaching liquids, oil, 100% humid air. I call this “unprotected” low temp.
  • Protect the food from the cooking environment – includes vacuum bagging (covered in the next installment of the primer), Ziploc bagging, plastic wrapping.

Unprotected Cooking Techniques:

100% Humid Air

You can’t cook low-temperature in dry air; for example, don’t try it in your oven. Dry air is a poor heat conductor and causes evaporative cooling at the surface of your food – making accurate temperature control impossible. 100% humid environments, like you can achieve in a combi oven, don’t conduct heat as well as straight water, but they can be very accurate. This kind of cooking is simple. Food goes into the cooker and gets pulled when it’s done; no wrapping required. The workflow is very intuitive for most cooks. But there are some disadvantages to 100% humid cooking; if you’re doing a cook-chill procedure the food isn’t protected from recontamination (it would be if it was wrapped); and during long cooking times (like several hours) the food’s surface tends to degrade.

Combi ovens and CVap ovens provide a 100% humid environment:

Combi Ovens

Combi oven.

Combi ovens are combination steam/convection ovens; modern ones can operate at low temperatures. The main advantage of combi ovens: they can  handle large amounts of food without getting bogged down by overloading, or by repeated opening and closing. Unfortunately, the ovens expend an enormous amount of energy to maintain this stability. Combis are also expensive and difficult to retrofit into many kitchens. And perhaps their biggest problem: they aren’t very accurate. Studies by Chris Young and Nathan Myhrvold show that while a combi oven’s average temperature can be accurate to within a couple of degrees centigrade, at any one moment it can be tens of degrees off. Combis should only be used to cook large items , like roasts, that won’t overcook in the ten minutes or so that it takes  the combi to swing back and forth around its target temperature.

CVap Ovens

CVap technology was originally developed for Kentucky Fried Chicken. Colonel Sanders needed something that would hold his chicken in perfect condition; he asked his friend and fryer guru, Winston L. Shelton, for help. In response, Shelton invented  CVap (Controlled Vapor) technology. CVap ovens are basically food holding cabinets with a bain marie in the bottom. Both the oven cavity and the bain marie are heated and temperature controlled. The cook can control the humidity inside the oven by adjusting the difference in temperature between the bain marie and the oven air. The core temperature of the food will not rise above the temperature of the bain marie. The surface texture of the food is controlled by the humidity of the oven air. You set the temperature of the oven air much higher than the water for crispy foods, like fried chicken, and you set it the same temperature for low temp cooking. For a detailed discussion of why the CVap works, see here.

CVaps come in many shapes and sizes, from very large down to single drawers like this one.

The inside of a CVap.

The Cvap comes in a range of sizes, is much cheaper than a combi, doesn’t require a lot of power, doesn’t require a water supply or a drain, and is extremely easy to retrofit. Many restaurants in New York City bought CVaps immediately after the Health Department  instituted HAACP control for sous-vide cooking. It is difficult to get a HAACP plan approved for sous-vide fish, and it is impossible to get one approved for fish below pasteurization temperatures (which is where we usually want to cook it). Since the possibilities of low temperature fish attracted many chefs to low temperature cooking in the first place, many took up the CVap.  It was basically unheard of in chef circles prior to the health department crack down. The disadvantage of the CVap:  it can start sucking wind if overloaded, or if the door is frequently opened and closed.

Cooking Directly in Water/Fat/Stock/Poaching Liquid

The immersion circulator is many cooks’ instrument of choice for low temperature cooking;  most cooks only use their immersion circulator with water. Take note: you can circulate any liquid you want –stock, beer, oil, duck fat, lard, apple cider, whatever. I am often asked if the circulator will be damaged by liquids other than water.  Happily, the answer is No.   If you ask Philip Preston from Polyscience (whose circulators we use) he will tell you the machines  aren’t NSF rated for direct food contact. It isn’t because the circulators aren’t safe for direct food contact, it’s just that getting the NSF rating would cost a lot more money than it is worth.  Here are the rules for unprotected cooking in the circulator:

  • Make sure the circulator is clean.  Circulate detergent to clean it.  Scrub the heating coils with a toothbrush.  We use the oven cleaning tablets from our combi oven manufacturer to clean ours.  Those tablets eat everything.  Other people use CLR (calcium, lime, rust) remover.  Do what you like, but keep those circulators clean.
  • Make sure you aren’t going to suck small items into your circulator pump. Any time you add herbs, burnt wood chips, crushed lobster shells, or any other flavoring to your bath, wrap it in cheesecloth first.
  • Be careful, especially with oil and fat, to get good circulation.  Bad circulation = bad temperature control and could = safety problem. The cooking liquid should be moving around all sides of the food at all times.
  • Never cook unprotected in a liquid that isn’t hot enough to kill bacteria.  We always keep our liquids above 54.4˚C (130˚F).

Tips for using a circulator to cook unprotected food. All of the parts that touch the cooking liquid are food-grade; but the machine isn't NSF rated for direct food contact because the rating would be too costly to obtain.

Unprotected Cooking in Liquid

Eggs are one of the few foods that we circulate directly in water. The whisk is just to keep them from rattling around in the circulated bath.

Eggs in their shells are cooked low temperature in plain water without any further protection –after all, they come pre-wrapped.  Most foods will have their flavors leached out if cooked in water (that’s how broth is made) but some foods benefit from cooking in stock or other flavorful liquid. These foods are prime candidates for unprotected low temperature cooking in liquid.  Fish can be cooked in a temperature -controlled court-bouillon.  Ham can be cooked in temperature-controlled apple cider. Bratwurst can be poached in temperature-controlled beer.  Most of the time, you are better off putting a small amount of your flavorful liquid in a bag with your food and doing protected low temperature cooking  – cooking directly in the liquid requires a lot of it.  Here are some cases where cooking directly in liquid makes sense:

  • If you have an item too big to bag easily, like a whole ham, that could also benefit from some added moisture and some mellowing (many hams are salty)
  • If you are cooking many of the same item over a period of time –like sausages:

 Let’s say you cook a couple hundred sausages a day. Start with a stock that complements your sausage. Use an immersion circulator to keep that stock at 60˚C (140˚F). Throw raw sausages into the stock to cook as you need them and pull out the cooked ones to finish on the grill. After a couple of hours your stock will take on a taste almost identical to your sausage.  The stock will taste like liquid sausage. I verified this phenomenon by paying five bucks to drink a cup of cooking water from a New York City hot dog vendor. After your stock has reached the liquid-sausage stage it is no longer changing the flavor of your sausages. The stock and the sausages are in equilibrium.  At the end of the day, throw some ice into your stock to cool it down and put it in the fridge.  The next day, bring your stock back to the boil to kill bacteria and start again.  If you added the right amount of ice the day before (determined by trial and error), you should be able to maintain a constant amount of stock indefinitely. In China, stocks have been continuously maintained this way for hundreds of years.

Getting liquid hot dog: cooking liquid in equilibrium with meat. Our intern Clifford scoped out the hot dog guy across the street, negotiated for a cup of precious hot-dog water, and got some.

Clifford with liquid hod dogs. This liquid smells and tastes exactly like a hot dog. It doesn't add or detract from the taste of the sausage. After hundreds of hot dogs were cooked in it, it is in equilibrium with the meat.

Unprotected Cooking in Fat

Circulating lamb directly in fat.

You can also cook directly in temperature controlled fat.  Fat doesn’t leach the flavors out of food and often provides a beneficial unctuousness. It is expensive to fill a whole circulating bath with fat, so use this technique in  circumstances like these:

  • Some chefs and customers attach a stigma to cooking in plastic bags; fat poaching, however,  has an aura of tradition and wholesomeness
  • If you are cooking a lot of the same item, it can be convenient to cook directly in fat.  No time is required for bagging. It’s  much faster to pull items directly out of a fat bath than to un-bag them.  The cost of the fat is less significant over a large number of items
  • Very large items –like a 36 inch striped bass –can be difficult to bag, and you might not want their flavor altered by a stock.  Cook them directly in oil or fat.

36 inch striper circulating in fat. All of the containers and other stuff in the bath is to minimize the amount of oil needed.

Protected Low Temperature Cooking

Most low temperature cooking work involves protecting the food from the cooking medium with some sort of impervious cover, which is almost invariably made of plastic.  The advantages of protected cooking are:

  • There is no loss of flavor to the cooking medium.
  • There is a reduced risk of contamination. 
  • Different types of foods can be cooked in the same vessel at the same time.
  • Protected foods are very easy to chill quickly after they are cooked.

The main disadvantages to protected cooking are the time it takes to wrap or bag the food, and some people’s trepidation about cooking in plastic.

Cooking in Plastic:

Many people are concerned about the possibility of chemicals from plastics leaching into foods during cooking.  I haven’t been able to get any firm data on the migration of plastic materials from bags and plastic wraps into food, but I’m fairly certain that at least a small amount of migration is likely to occur. Whether or not that degree of migration is harmful is up for debate.  

Many people are currently worried about the plasticizer Bisphenol A (BPA).  Here is what the US government has to say about it.  BPA is used primarily in polycarbonate.  While we don’t wrap foods in polycarbonate, low temperature cooking is often done in polycarbonate containers (eg Lexans or Cambros).

Polyvinyl Chloride, another commonly used kitchen plastic , contains a whole mess of plasticizers –usually a group of chemicals called phthalates.  As far as the PVC industry is concerned, phthalates cause tumors in rodents but not in primates –even in larger than normal doses. Other people are not so sure. Who knows? Many commercial plastic wraps are made of PVC.  Often, these wraps smell bad –indicative of residual solvents and whatever is was used to make them.  Aside from any purported health issues, bad smelling plastic wrap can most definitely make your food taste bad. Fatty foods like cheese are more likely to pick up bad odors from plastic wrap. Don’t use plastic wrap that smells bad.  On the positive side, PVC is a pretty good vapor and moisture barrier and can have pretty good heat resistance.

 Polyethylene, in its many guises, is another major plastic used to wrap foods. Most supermarket plastic wrap is made from polyethylene (PE).  Polyethylene is usually plasticizer free –which is good news.  Polyethylene wraps usually have some chemicals added to increase cling –often ethyl vinyl acetate (EVA) and polybutene (PIB).  I haven’t found any health concerns on these two ingredients.  The bad news about polyethylene is that it doesn’t tolerate very high temperatures and it is not a very good gas barrier. Plastic wrap is an especially bad gas barrier because it is made from low density polyethylene (LDPE).  Food wrapped in LDPE will still oxidize.  Odors might also be able to penetrate LDPE. Use several layers.  Ziploc bags, as far as I can determine, are usually made of polyethylene.  The freezer Ziplocs are better gas barriers than standard Ziplocs, both of which seem better than plastic wrap.  Perhaps Ziplocs are just thicker than plastic wrap, maybe they contain some other type of polyethylene.  I don’t know.

Packing Without the Vacuum:

Ziploc Bagging:

Ziploc bags are excellent cook-chill tools.  At the school we always call out Ziploc, rather than re-sealable bags, because many off-brands don’t work.  The seals fail, the bags come apart when cooking, etc.  Do not purchase the Ziploc with the sliding do-dad.  Get the regular double-seal type.  We buy the freezer storage bags because they are supposed to act as a better vapor barrier than the regular type, and they are rated for re-heating in the microwave.  We stock quart and gallon size bags.  If you learn the proper technique for bagging, Ziploc bags can get almost as tight as a vacuumed bag.

The Technique:

  1. Fill a container with water deep enough to easily submerge your food and bag.
  2. Always add some sort of liquid to the bag –fat, stock, sauce, etc.  The liquid is necessary to fill the gaps around your food and expel the air from the bag. 
  3. Add your food item.  A significant advantage of Ziplocs over vacuum bags is that the food can be added to the bag hot.  All vacuum bagging procedures require your food to be cold (more on that in the upcoming vacuum section of the primer).  If you are searing meat and adding it directly to the Ziploc bag make sure the surface of the meat is below 100˚C (212˚F) or the bag will melt.  Be especially careful to not touch the bag with a hot set of tongs or spatula.
  4. Close the seal of the bag almost to the edge, leaving the last portion of the seal open –make sure you have correctly sealed the bag.  Put your finger in the corner to make sure that part of the seal is open.
  5. Carefully immerse the bag in the water starting with the  closed corner, not the open one. Make sure you do this step carefully,  allowing  air to escape up and out of the open corner.
  6. Just as the open part of the seal is about to go under the water, close it up.

1. Fill a container with enough water to submerge your product. 2. Make sure there is liquid or oil in the bag. Add your product and seal the bag except for one corner. Put your finger in the open corner and start submerging your bag like it shows in the picture. Submerging as shown will minimize the amount of trapped air.

1 and 2. Submerge the bag and work out all the air. 3. Just before the last corner goes underwater, remove your finger and seal the bag completely.

Finished Ziploc. No air bubbles. Almost as good as a vacuum.

The advantages of the Ziploc are:

  • you don’t need to buy a vacuum
  • food can be bagged hot
  • food can be removed from the bag and re-bagged easily
  • the process is very gentle on foods and doesn’t change food textures the way vacuum bagging can
  • it’s just as effective for cooking as vacuum bagging for most items

The disadvantages of the Ziploc are:

  • not as convenient for bagging a lot of items as the vacuum machine
  • Ziplocs cost more than vacuum bags
  • doesn’t provide some vacuum benefits –fast marination, extended storage, oxygen removal.

Wrapping in Plastic Wrap:

Rolling foods in plastic wrap is an excellent preparation technique for low temperature cooking. Rolls cook evenly and are easy to portion.  We often combine rolling with some meat glue (see the transglutaminase primer).  Properly rolled roulades in plastic wrap will not allow water to penetrate.  Really good rolls are dense –they will sink.  Here is the technique in pictures, borrowed from our transglutaminase primer.  Remember –making good rolls isn’t as easy as it looks.




Another option for plastic wrapping: the cannon ball.  Place the food to be cooked in a square of plastic wrap and twist to form a ball.  Tie up the loose end.  The part of the cannonball near this loose end isn’t going to be very pretty –serve it face down on the plate.

1. Mis en place for the cannonball. Plastic wrap and either butchers twine or a length of twisted plastic wrap to tie off the ball. 2. Put your product in the center of the plastic. Normally, we would add some meat glue.

1. Gather up the meat. 2. Use your hand to squeeze out most of the air and form the ball. 3. Make sure to get out the air at the point where the plastic wrap comes together.

1. Twist the cannonball to form the shape. 2. What your cannonball should look like.

If there are large air bubbles in the ball you can poke them with a skewer and they will go away. If you poke the wrap with a skewer you'll need a second layer of plastic.

1. Place the cannonball in another piece of plastic wrap. 2. Squeeze the air out and reinforce the ball shape. 3. Twist to lock.

1. Tie the cannonball off. If you use string as pictured, be careful to not rip the plastic. Tying with plastic minimizes this risk. 2. The finished cannonball.

The underside of the cannonball looks a little wonky. Serve this side down.

Whenever you use plastic wrap, use a brand that doesn’t smell bad.  If you are worried about phthalates, use polyethylene  instead of PVC.

Next installment: the vacuum machine. 

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44 Comments so far ↓

  • sygyzy

    Chef, could you please spend some more time talking about how to clean IC’s? I have one that has little calcium deposits (my water is heavily calcified) and I am afraid of using chemical cleaners or detergents to clean it. I don’t know what to do and don’t want to break anything.

    • davearnold

      Howdy Sygyzy,
      CLR, the calcium lime rust remover you get in hardware stores, won’t hurt the circulator. Philip Preston himself told me so.

  • Danny B

    Chef, thanks for another awesome primer. I love the side note on hot dog stock – despite frequently reflecting that it smells precisely like a hot dog, I had never considered it in terms of an equilibrium.

    In any case, I will put this to good use – I’m building a thermal immersion circulator with my housemate this weekend!

    • davearnold

      Nice Danny B,
      What parts are you using? What is the current preferred pump? I haven’t built one from scratch in years. I’m sure the pumps are better now.

      • Danny B

        Not sure about the pump yet, but we’ve got a 250W immersion heating element, thermistor, controller, and some time to mess around with it. The goal is to make a unit we can clip on to an arbitrary container (within the limit of our element’s ability to maintain temperature) for increased versatility.

        I wasn’t actually sure, with a smaller basin and bending the element into a vertical coil, whether we could get even heating through convection alone or would need a pump. If measurements show that we’re getting hot and cold spots, I’d guess aquarium supply might have what I’m looking for (unless they can’t handle the higher operating temps in this application).

        Any suggestions you might have would be appreciated, and I’ll let you know how it goes!

        • davearnold

          Howdy Danny B,
          As per your next comment, your heating element is underpowered. Commercial units are almost all 1000 watts. I once built a circulator using a bunch of immersion coffee warmers. They leaked a lot of current –gave off quite a shock.

      • Danny B

        Actually, some order of magnitude calculations make me think that our heating element might be way underpowered (at least for a larger polycarbonate bin – for a smaller insulated bin it might still be okay). Will play around with it this weekend and see where we get.

  • suji

    Chef Dave,
    How are you? Thanks again for the excellent primer. You are genius!! Thank god we don’t have that legal problem of using the vacuum machine in Asia.

    Are you around in school on the 19th of April? Can I see you around 2pm? Yes, I will be back to NYC..

    Cheers,
    Suji

  • John Bailey

    Chefs,

    Thank you so much for adding this additional information. I use a Minipack-torre MVS31 vacuum machine at home for low production sous vide. Provided I am going from raw food to a vacuum to sous vide to the table without storing, I am not sure why the process would be ‘iffy’? I am fully conversant with Baldwin’s thoughts on danger zones and pasteurization and try to follow the times recommended, but then again I fear harming myself or a guest. I assume the biggest danger is preparing quantities ahead of time for bringing back to serving temperature for later service. Then again, I find using my vacuum for regular leftovers, freezing fresh items and extending refrigerator life to be another machine benefit. Perhaps in your next installment you can help those of us with vacuum machines to be walking on the safe side.

    Also, I have at home a Rational 61 self cooking center in my kitchen, but have not tried to use it for sous vide. Are you suggesting that it is possible to cook sous vide without putting items in a plastic bag? I also question how steady the temps are over time and that they may vary more than one would wish. I have not experimented with it because I understand that Rational makes a specific sous vide version of their self cooking centers, but that existing machines cannot be retrofitted. Also, thanks for the idea of using the cleaning tablets for circulators. More information and comments about further techniques for cooking with Rational ovens, I am certain, will be appreciated by many of us using them.

  • Matt

    Wonderful post. Many thanks. I’m so glad to have this resource available (although I must admit that some of the fun of sous-vide cooking is that there’s so *little* information available–we have to figure it out for ourselves)!

    My question: I’ve had my immersion circulator for a month or so. While I like it, I’ve been frustrated that so many recipes and techniques require a vacuum sealer (mostly b/c of liquids in the bag but also for compression and other technique). So, I’ve resolved to buy a chamber sealer and settled on the MVS31. However, this post has me thinking that perhaps I don’t need it.

    The question: if you were an adventurous home cook with an IC and were willing to blow $2K on a piece of kitchen equipment, is a chamber vac the right purchase–and if not, what would you get?

    • davearnold

      Hi Matt,
      The MVS31 is a great little vacuum machine. Nils and I both like it. We both wish we had one at home. If I were told to spend 2 grand on a piece of kitchen equipment I think I’d get the vac. Paco Jets are nice too, but they are over 3 grand and I’d get the vac first. It depends on how much of a hardship the money is for you. Before I’d get the vac I’d make sure you have a vita-prep, champion juicer,etc.

  • derek

    Regarding the leaching of plastic: I’ve considered using corn husks, banana leaves, or other wrappers as liners between the food and plastic to limit migration of plastic into the food. Do you think this would be effective?

    These items would obviously impart some flavor to the food they contact. Do you think that the effect of the vacuum would make the flavor stronger than, say, steaming it in the same wrapper would?

    • davearnold

      Interesting question Derek,
      If the leaves are aromatic they will probably taste more intense in the bag. Try it out and let us know.

      • KennethT

        I’ve done some pulled pork wrapped in banana leaf – about 8 hours at 80C… the banana leaf flavor was very present. Not sure what would happen at lower temps though…

  • AJ

    Hello again Chef! I’ve been tasked with creating and implementing a HACCP plan for sous-vide in our kitchen. Since I’ve found your guides to always be clear, concise and efficient, would you mind sending me the HACCP portion of your primer? Even in draft form, I’m sure it would save me a good deal of time. If that’s not possible, a few quick links/pointers to outside resources would be appreciated. I just don’t want to go down a rabbit hole and unintentionally build a NASA style HACCP plan when something tighter and easier fulfills our needs.

    Thanks so much!

    • davearnold

      Hi AJ,
      The actual HACCP plan at our school was written by Christina Tosi, the chef at Milk Bar here in NY (Besides running the pastry department at the Momofuku empire, Tosi also writes HACCP plans), so I am not at liberty to send it (unless she tells me I can) and I haven’t yet written the section of the primer that deals with HACCP plans in detail. HACCP plans are different for every kitchen depending on your equipment, menu items, etc. Luckily, HACCP plans for restaurant sous-vide are much simpler than plans for larger commercial packing plants. The main problem with writing a HACCP plan is knowing what the Board of Health will let you get away with. Using someone like Tosi who deals with the health department on a daily basis saves a lot of time and headache.

  • Dennis

    Hi Chef, thanks for another great primer!

    Under the disadvantages for Ziploc bags you mentioned insufficient oxygen removal.

    Via Baldwin’s SV primer, I saw this article:

    http://www3.interscience.wiley.com/journal/109581520/abstract?CRETRY=1&SRETRY=0

    Two small-scale industrial trials found high levels of residual oxygen in the majority of bags of lasagna packed at 70% vacuum. After a few weeks the oxygen had reacted.

    I don’t know anything about this article or journal, but it makes me wonder. Do you have any information on the study or on this problem in general?

  • Linh-Dang

    Chefs might not want this in their kitchen, but I’ve done well with a DIY vacuum pump made by reversing the check valves on a bicycle pump (instructions on instructables.com) Works great for marinating food in the foodsaver bags. What you need to minimize mess is just a trap flask (available from any science surplus store), appropriate tubing and a small flat surface to elevate the foodsaver bag’s vacuum port above the marinade level. Pump away (literally for me) and stop after sucking a bit of the marinade out of the bag and into the trap flask.

  • Perros

    Have you had a look at this:

    http://www.seriouseats.com/2010/04/cook-your-meat-in-a-beer-cooler-the-worlds-best-sous-vide-hack.html

    It seems like an interesting budget approach to sous-vide. I just wondered if you’d tried something similar?

    -Perros-

    • davearnold

      Howdy Perros,
      Yes, I’ve done that. My feeling is it is a pain in the rear. Here are my general thoughts: If you are an all grain brewer, you are used to calculating the strike temperature of your mash — a similar technique should be used when “cooler cooking.” First figure your cook time and temperature drop. Add the amount of water (plus extra to simulate the weight of food) you intend to use to your cooler. Make sure the water is in the temperature range you intend to use. If most of your cooking will be between 55-60 C, try 57C. Now test the temperature drop every half hour (or more). It is better if you use a thermometer that doesn’t require you open the lid. You only have to do this one time. Now you know the heat loss out of your cooler in degrees per hour. This figure won’t change much unless the temperature of your kitchen changes. Now… Calculate the weight of water you will use and the weight of your food. Use this formula: (The temperature of water you should use)=((weight of food +water)*(temperature you want to cook at)-(weight of food)*(initial temperature of food))/(weight of water). Sorry for the hard to read formula. After you get the beginning water temp, add the number of degrees you need for the heat loss over the cook time. If you lose 1 degree per hour and have to cook for 1 hour, and your theoretical initial water temp is 58 degrees –use 59 degrees. Be careful with this last step. It is often better to let the center be under a degree or so and not overcook the outside.

      In the article he is only cooking one item in a very large amount of water. This allows him to forgo the former calculation, but underscores the limitations of the process.

      • Kenji Alt

        Good points Dave. It’s obviously not a functional solution for recipes that require extreme precision. But I find that for simple quick-cooking things like steak, chicken, fish, etc, it’s close enough. Personally, I can’t tell the difference between 130 degree steak and 131 degree steak, and with my cooler at least, it only lost about 1 degree per hour in my kitchen, so even if I cook a fat steak for three hours, I get the temperature to within a couple of degrees of my target.

        I did a party for 25 people with this method a couple weeks ago and it worked fine – though I did have to use a much larger cooler. I cooked both beef and a fish course in it, then held them until serving with no problems.

        You are absolutely right that it has some pretty severe limitations if you are really serious about what you do, but I think for most home cooks, the results, cost, and flexibility make it a worthwhile trick to have. It’s particularly great for bbq’s!

    • Linh-Dang

      I haven’t tried sous-vide cooking yet, but the beer cooler seems like a good idea for a container. I’ve a aquarium pump, thermocouple -> switch/relay and an immersion heater set up, but finding a good insulated container hasn’t been easy – the biggest stock pot I have hasn’t been doing the job.

      • davearnold

        Linh-Dang,
        What wattage of heater are you using? If you have a PID controller you shouldn’t need to use a huge stock pot. If you use an on/off switch and also use insulation, it will be more difficult to get rid of excess heat in an insulated container.

        • Linh-Dang

          Hi Dave,

          Thanks by the way for the great blog. I have learned a lot!

          I got a 1000W immersion heater – I think the intended use was for people living out in the boonies to heat up barrels of water. Overkill? Never thought about getting rid of excess heat before.

          If it’s a problem a potential solution is to have a hot water reservoir w/ the heater, and a pump that’s also controlled by the PID that will push hot water into the cooking vessel. When off, there would only be passive diffusion between the two. The thermocouple would be in the cooking vessel.

  • coyote

    Is there any reason not to use the ziploc “vacum” method for prolonged cooking, ala 48 hour short rib?

  • Levi Stewart

    Ziploc is, in my experience, the only brand you should use for sous-vide. This is especially true for longer term cooking (i.e. 48 hours). Other bags are likely to tear or open up during cooking, which, for me, leads to bouts of cursing and being upset.

  • Akiko Thurnauer

    Hi Chef,
    So, what is Sous vide regulation in 2011? I know many small restaurant use ziplock bag to do sous vide without HACCP plan. I’m planning to open small restaurant this June. I really like to use sous vide.
    but, It’s such a pain to get HACCP plan.is there any license I have to apply for use sous vide??

    • davearnold

      Hello Akiko,
      To use a vacuum machine at a restaurant in NYC you need to write a HACCP plan which gets approved by the board of Health. I wouldn’t write this plan yourself unless you have a lot of experience, because it helps to know what will get approved and what won’t. Christina Tosi (the head of Milk Bar) writes good HAACP plans and knows what the Board will go for. You will need a series of procedures (recipes) that are approved –you are only allowed to use sous vide for these procedures. You will have to log the temperature of food when it arrives, the temperature and time at which it is cooked, and log verification of chilling in the proper amount of time. In addition you will have to have a specified sous-vide fridge that is always kept below 38F (really 34 is better if you want extended shelf life) and whose temperatures are logged daily. Your establishment is then also subject to additional inspections (for the purposes of verifying your HACCP plan only). It is a pain, but it is often worth it.

  • Ryan

    Hello Chef,

    I love your posts. I have a vacuum sealer by ary and I am looking for any tips on vacuum sealing without freezing the liquids first. Also any cool vacuum sealer tricks would be great

    • davearnold

      Howdy Ryan,
      Which Ary? The Vacmaster? It looks like it should do liquids OK.

  • Shaun

    just finished my first HACCP plan for ROP,is sous vide nesessary to add to the plan or would you suggest just ziplock.?

    • davearnold

      If you have HACCP for ROP it should include sous-vide. I use ziplocs for some things even if I’m able to use sous vide instead, but sous vide can’t be beat for certain applications.

  • Shaun

    i ask cause my chefs realy want rop sous vide and i think its a waste of time.

    • davearnold

      Getting the HACCP is a hassle. If you can get away with ziplocs and you aren’t using extended shelf life I might go non-sous-vide low temp for a while. If you need the long shelf life you need the ROP.

  • Robert

    Chef,
    I have used Sousvide /vacuum cooking plenty in Chicago,
    I have returned to NYC to open a Restaurant.
    Is there any consultants and or assistants for implementing and creating the mandatory haccp plan? (I’m sure a fee is involved ,this is not a concern)
    …………….is there a license or obtainable certificate and so on?
    Thank you very much in advance
    Robert

    • davearnold

      Yes Robert. There are several people who do that here. Christina Tosi is my fav, but she is super busy.