Sous Vide: Recipes, Techniques & Equipment (Part 2)

[BryanZ]

There are extensive posts about this back in the thread by Nathan. To sum it up in layman's terms, it's something like the longer you keep something about 125ish or so the less harmful bacteria that survive. So far, we haven't heard any eG horror stories, so it''s seeming pretty safe.

Look back and browse through this thread for a lot of good info.

[docsconz]

At my Medical School Class Reunion last night I had the chance to chat with Tom Frieden (himself an avid food aficionado), the NYC Commissioner of Health and a classmate of mine in Medical School about the status of sous vide cooking in NYC. He assured me that there is no such thing as a ban on sous vide cookery in the City, however, they feel that the technique is potentially dangerous and that any restaurant that aims to use the technique needs to have a plan registered with and accepted by the Department of Health. Of note, he said that the whole issue came about because there apparently have been five cases of botulism related to the technique. he did not specify whether they were in the City or throughout the world or over what period of time they occurred. I would have loved to talk more with him about the topic, but therer was a lot of re-uning going on and I didn't have the opportunity to follow-up on it any further.

[nathanm]

Until this is docomunted I am very skeptical that the five botulism cases from sous vide mentioned in docsconz' post actually happened. They might have - but I searched extensively and have found nothing on the internet about it.

The Center for Disease Control publishes reports on every outbreak worldwide - for example a botulism outbreak in Thailand in March 2006 from eating home-canned bamboo shoots, or one from Alaska in 2002 where people actually ate a beached whale carcass they found.

The latter CDC report reaches this conclusion "Persons should avoid eating beached marine mammal carcasses". Gee, you think you can comply with that? I'm going to.

Alaska is, per capita, the botulism capital of the US. From 1950 to 1996 there were 72 cases in Alaska, versus 12 in New York state, despite NY having a vastly larger population. Only California had more cases than Alaska at 85, but it is the most populous state, so on a per capita basis it falls way below Alaska. The reason Alaska is so high is that many traditional Native Alaskan foods are prone to botulism.

This an other facts about botulism come from the CDC Botulism Handbook

The CDC lists NO cases of botulism due to sous vide. Since they pretty much cover the world, I would be surprised if there are 5 recent cases that they don't know about, although of course that is possible.

The CDC does not list any other illnesses caused by sous vide either, although they probably do not track mild cases of food poisining which are apt to go unreported.

So, while botulism remains a serious theoretical concern for stored sous vide, I am not aware of any actual cases in practice.

Nathan

[docsconz]

I am not aware of the specific cases either. Dr. Frieden wasn't in a position to to document the specific cases at that social event. it could even be that it was a number he pulled in off the top of his head. The evidence may not even be more than anecdotal. I am not even sure that the cases are documented if in fact they really did happen. I am simply reporting what I was told. Nevertheless, the possibility certainly exists. The bottom line is that I was told that the NYC DOH in no way wishes to outlaw, ban or get rid of the technique of sous vide cooking. They just want it used by people who have an understanding of the potential complications.

[bigred93]

I'm nowhere near as expert as Doc or NathanM but I too am skeptical of an "outbreak" of five supposed events in New York with absolutely no news coverage at all.

I also can't help to add... I'm not one to judge, but gosh: mmm mmm, beached marine mammal carcass.

[docsconz]

The word "outbreak" had not been used until you used it. I also didn't say that he said the cases were necessarily from NYC. As I said I can't be sure that the five cases really even existed as I was not in a position to gather documentation in a social situation. The point I was trying to make was that sous vide is very much in play in NYC and that the DOH does not have anything inherently against it. I thought the mention of "five cases of botulism" interesting and so mentioned it here. Frieden is a smart and trustworthy guy who IMO has done a very good job as COH for NYC.

[Digijam]

- If a sous vide bag puffs up, throw it out!  Many pathogenic bacteria generate gas.  Also, if the bag smells "off", throw it out. 

←

Just to clarify, I assume you mean puffing occuring in storage, rather than any ballooning that might occur during cooking? Presumably the latter is almost inevitable without the aid of a pro-level (chamber-based) vac system?

[UnConundrum]

Only time I've seen puffing with a foodsaver is when I added alcohol to the bag before cooking.

[nathanm]

The word "outbreak" had not been used until you used it. I also didn't say that he said the cases were necessarily from NYC. As I said I can't be sure that the five cases really even existed as I was not in a position to gather documentation in a social situation. The point I was trying to make was that sous vide is very much in play in NYC and that the DOH does not have anything inherently against it. I thought the mention of "five cases of botulism" interesting and so mentioned it here. Frieden is a smart and trustworthy guy who IMO has done a very good job as COH for NYC.

←

The CDC uses the term "outbreak" for a cluster of related cases, which can be as little as one. A "case" is an individual person being sick. So, if there were 5 cases it could be outbreak or 5 outbreaks if they occured separately.

We would all be interested in learning of this sort of event, and I think it was helpful of docsconz to mention it in this thread. Until we have more details we don't know much more about it. Also it is interesting that the DOH recognizes that sous vide is not a bad technique, and is merely one they want to regulate.

[nathanm]

- If a sous vide bag puffs up, throw it out!  Many pathogenic bacteria generate gas.  Also, if the bag smells "off", throw it out. 

←

Just to clarify, I assume you mean puffing occuring in storage, rather than any ballooning that might occur during cooking? Presumably the latter is almost inevitable without the aid of a pro-level (chamber-based) vac system?

←

Correct - I mean puffing up during storage, not during cooking.

During cooking the residual air in the bag (there always is some) heats up and expands so you will get some puffing due to this. If you seal with an edge-sealing vacuum machine this often happens because the vacuum you get is not all that great.

If you heat the bag up near the boiling point of water you will certainly see it puff up due to steam.

If the bag contains something with a low boiling point, like alchohol (boiling point 78C/ 172F) then you'll get puffing as you approach its boiling point.

All of this is harmless. The problematic puffing occurs during storage of the bag. If the bag is reasonably tight after cooling, and later becomes puffy it means that something in the bag is generating gas, likely bacteria. In that case throw the bag out!

[harryotto]

The lowdown on the NYC "Ban"...

When the New York City Department of Health came down on some of the restaurants for vacuum packing foods, as well as sous vide cooking, they did so because some of the kitchens could not properly articulate a well designed HACCP Plan. The day after the Health Department began giving out violations, kitchens like WD-50, Daniel and Per Se got in touch with food scientists and developed written HACCP plans.

The health department inspectors saw food being packed in unsanitary conditions and held outside of the temperatures that would prevent the formation of the Botulism toxin from Clostridium Botulinum spores.

If you MAP vacuum pack food for holding or sous vide, it must be kept at 37F or below. No exceptions. Even if your pH is under 4.6 (what would be considered highly acidic), without a solid grasp and understanding of pH and spore growth, the health department doesn't want to hear about it.

As far as ribs being sealed and cooked 36 hours at 131F, you could not create a botulism toxin if you tried. The USDA, after inoculating their samples with 1,000,000 times the amount of spores normally found in food, were able to develop a toxic strain in 8 days, under the perfect pH and temperature values (around 79F). In other words, in takes weeks and weeks, if not months, for a sous vide pack to create a botulism toxin.

So what's the problem? Problem is that when health inspectors asked these cooks what their safety plan was, they looked at the inspectors with no answers. In my restaurant, and the restaurants that I have taught to properly vacuum pack and store foods, they must follow a solid safety plan as follows:

1. The vacuum sealer, either MAP chamber or foodsaver style, must be located in a separate and sterile environment

2. You must have your specs & permeability ratings from your bag supplier. They must be food grade.

3. You must have a sticker on each bag, in English and Spanish, stating "WARNING - MUST BE KEPT AT 37F or FREEZING - DANGER".

4. You must date each package. USDA recommends no more than 2 weeks holding time.

5. Someone must be able to reference the 2005 Food Code and USDA recommendations on MAP preserving.

If anyone has any specific questions on foods, food borne illness and how they relate to MAP sealing and sous vide, please ask.

[Dave Weinstein]

After digging through this thread, I decided to give it a try. For simple work, I already had the necessary tools, a FoodSaver machine I had picked up a few years ago (for general purpose freezing), and an electronic thermometer with probe (purchased originally for high temperature roasting).

The plan:

Truffled chicken breasts cooked sous vide, served with salad and a saffron risotto (an easy microwave dish, thanks to Barbara Kafka).

Ingredients:

Two chicken breasts, pounded flat

FInely sliced fresh leek

Oyster mushrooms

One tablespoon butter

One tablespoon White Truffle Oil

One teaspoon Hawaiian Salt

Notes:

Managing the temperature was more work than expected, but I was able to keep it (roughly) at 142 F (although it kept trying to go lower, and occasionally higher). The momentum involved in shifting the temperature was tricky.

The salt had me worried, until I realized that I wasn't seeing pink meat, but rather the coloration from the salts.

Results:

The truffle oil did not leave significant flavor (certainly not enough for the amount used), and next time I'd leave it out (and save it for other dishes). The leaks imparted a lovely flavor, as did the butter and the mushrooms, and the texture of the chicken was fantastic.

Final thoughts:

I want a circulator. However, I'm not comfortable with recycled lab equipment when I don't know what was in it previously, and the costs of new circulators are too high. So I suspect I'll limit myself to chicken and fish, where I can monitor the temperature myself without going mad.

[joesan]

Calling Nathan and all other Low temp guys!

I don't have access to sous vide equipment at the moment so I am cooking at Low Temp for a Long Time (LTLT) in my oven. I want to cook a joint of beef ("Silverside" in the UK) that weighs about 0.82kg. My oven is very stable and works in 5C increments.

I like Heston Blumenthal's recipe that involves cooking the meat at 75C until the core reaches 52C (takes about 2 hours to get there). However this cut of beef is never quite tender enough with this method.

My question is - can I leave the meat longer at a lower temperature to get a better result by breaking down more of the meat fibres? My oven goes as low as 50C, 55C, 60C, 65C etc. and it has an accurate internal temp probe to judge when the correct internal temperature is reached.

What time / temp combination do you think would be optimal?

[jmolinari]

Quick question.

As i understand sous vide, leaving the meat in the bag and bath at the final temp for long times (10-15 hours) is safe. Does this mean that i can bag my chicken breast in the morning before leaving for work, put it in the bath at 140, and come home to a ready dinner?

I've read through the thread regarding sterilization times, and all that, so it seems like this method should be perfectly fine, correct?

thanks

jason

[edsel]

joesan, nathanm's summary of time / temperature combinations starts at this post, with tables in subsequent posts. I'm not sure what the difference is between low-temp oven cooking vs. water bath. (Does the heat transfer difference affect the cooking time?) Lower tempertaure / longer time should benefit any tougher cuts of meat.

Jason, super-long times tend to give poultry a dry texture, but that's just my opinion. Maybe others have had success with it. If I need to do something like chicken breast ahead, I cook it for a shorter time and chill it quickly in an ice bath. I reheat at a higher bath temperature, keeping an eye on the internal temperature. I believe you're OK on the safety factor - others will probably correct me on that.

[jmolinari]

edsel, you've found the chicken gets dry even if it is cooked at 140? I thought it could be kept near indefinitely without runing the texture since it'll never overcook?

thanks!

jason

[nathanm]

Calling Nathan and all other Low temp guys!

I don't have access to sous vide equipment at the moment so I am cooking at Low Temp for a Long Time (LTLT) in my oven.  I want to cook a joint of beef ("Silverside" in the UK) that weighs about 0.82kg. My oven is very stable and works in 5C increments.

I like Heston Blumenthal's recipe that involves cooking the meat at 75C until the core reaches 52C (takes about 2 hours to get there). However this cut of beef is never quite tender enough with this method.

My question is - can I leave the meat longer at a lower temperature to get a better result by breaking down more of the meat fibres? My oven goes as low as 50C, 55C, 60C, 65C etc. and it has an accurate internal temp probe to judge when the correct internal temperature is reached.

What time / temp combination do you think would be optimal?

←

Most Combi ovens have a program that lets you hold meat for 24 hours at low temperature. What you want to do is maintain the oven so the internal temperature is 55C. The oven temp will be higher than this becaues there will be some evaporation from the roast. The exterior will dry out a bit but that should be OK because you'll sear it anyway. I can't say exactly what temperature to set it at to stabilze at 55C internal, it depends on the size of the meat and other factors.

Alternatively if you seal the roast in a plastic roasting bag you will not lose moisture to evaporation. Roasting bags are sold in the supermarket - Reynold's Oven Bags are one brand in the US - I assume there must be a UK equivalent.

Put the meat in the bag, and seal it with the nylon bag tie (included with the bag). In that case you ought to be able to cook it at or just above the desired temp - say 55C to 56C.

Once sealed in the bag it is an approximation to sous vide. There is air in the bag, but in this case it really doesn't matter. The key thing is to seal in the moisture. The inside of the bag will be very moist - the air will be at 100% humidity - but that is what will stop the evaporation.

Note that there is no food safety problem with having the meat at 55C overnight like this - at least according to US FDA standards. Also, 55C is low enough to still have decent meat color, but high enough that you should get some tenderizing effect.

A similar product for containing the moisture is Reynold's Hot Bags - which are an aluminum foil bag. One could also attempt to tightly seal the meat in conventional aluminum foil, however in that case it is highly likely that you will have some leakage because you can't seal the foil as well as you can the bag.

You can sear the meat either before or after. Put oil in a pan, heat it until it just starts to smoke, then put the meat in just long enough to get the desired sear color.

[nathanm]

Quick question.

As i understand sous vide, leaving the meat in the bag and bath at the final temp for long times (10-15 hours) is safe. Does this mean that i can bag my chicken breast in the morning before leaving for work, put it in the bath at 140, and come home to a ready dinner?

I've read through the thread regarding sterilization times, and all that, so it seems like this method should be perfectly fine, correct?

thanks

jason

←

Your motivation for the long cooking time seems to be to leave it cooking while you are at work and have it ready when you are back. I do this all the time for beef, lamb or other meats which can tolerate the cooking time. However, chicken breasts may, or may not be as suitable.

The typical reason to leave meat in a sous vide for a long time period, like 10-14 hours is primarily to allow the collagen to denature into gelatin. Most toughness in meat is due to collagen, and it will slowly break down (denature) into gelatin. The lower the temperature, the slower it takes. If you cook red meat at 130F - 140F then you need quite a bit of time.

Tender meats don't start with very much collagen, and they need some of it to have reasonable texture and mouthfeel. With very long cooking they can become so tender that it gives a mushy texture which is undesirable. As an example, you can easily ruin a fillet mignon (to my taste anyway) by having it cook for 10 hours.

I have never tried cooking chicken breasts for more than a couple hours, and they are fine up to that point. It is not necessary to cook them longer to tenderize the chicken (unless perhaps it was a very tough old stewing hen).

From a food safety perspective there is no problem with cooking food at 140F for 10-12 hours.

In addition to collagen denaturation, there are other changes in the food over time, and ultimately the quality of the meat will degrade. I have cooked beef for 96 hours without trouble (if it starts out as a tough cut). However I have not explored this with chicken so I don't know what the ultimate limit is.

[nathanm]

edsel, you've found the chicken gets dry even if it is cooked at 140? I thought it could be kept near indefinitely without runing the texture since it'll never overcook?

thanks!

jason

←

Sous vide does not overcook from a temperature perspective if you have it in a bath that is the desired core temperature.

However, the cooking process for food is a combination of time and temperature, and over a long enough period of time you can definitely change the quality of the food. If it is tough, you tenderize it. But there is always the possibility of too much of a good thing...the heat causes too much collagen to break down ruining the texture. In addition other changes can occur.

It is hard to accidentally overcook in sous vide because typically you have to leave it for many many hours to get a bad effect. But you can't leave it indefinitely.

[jmolinari]

Thanks Nathan. I'll ahve to give it a try and find out if the chicken is still edible after being in the bath for 12 hours. Just wanted to double check i would be safe.

jason

[joesan]

Nathan (and Edsel) - thanks for the tips. Going out to look for some Roasting bags. I thought an internal temperature of 55C might be overdone but I will give it a try.

I'm thinking of trying about 7 hours. Will report back.

[nathanm]

I regard 55C / 131F as medium rare for beef. For rare I will go down to 122F / 50C. There seems to be little or no agreement as to what temperature range corresponds to terms like rare, medium rare etc.

Holding at 50C temperature overnight under the conditions I explained is not recommended - there are food safety concerns.

[joesan]

55C is not as rare as I would like but given that my oven will either do 50C or 55C - I think I will have to settle for 55C. Hopefully the tenderizing effect of the LTLT will offset any drying out of the higher internal temperature. I will be serving it cold anyway with an Italian salsa verde so that should also help.

[edsel]

edsel, you've found the chicken gets dry even if it is cooked at 140? I thought it could be kept near indefinitely without runing the texture since it'll never overcook?

←

Maybe "dry" isn't exactly the right word, but the texture changes over time. As Nathan says, you can prevent the food from exceding the target temperature, but it's the combination of time and temperature that determines how done the food is.

Long-cooked chicken breast isn't really bad, just not ideal as far as I'm concerned. You might give it a try to see what you think.

[Reefpimp]

Has anybody tried doing like a duck galantine en sous vide? Would there be any benefits to this? I'd think that with just a bit of the poaching stock frozen and put in the bag, one could achieve better control of the cooking of the force and interior garnish.

Thoughts?