nathanm

For the avoidance of doubt, Nathan, are you suggesting 'naked' or 'bagged' boiling? And doesn't this crop up again with comminuted meat products, where the 'outside' ends up inside? ← For the pre-sous vide blanching you should do it naked. You could do in the bag, but some SV bags get soft at that temp. Comminuted (i.e. tenderized, ground, jaccarded) has already had inside and outside mixed, as you say. So there is not that much point in pre-sear or pre-blanch...

Not really.... 131F/55C is at the edge of officially endorsed FDA / USDA temperature-time relationships, but it IS within. Of course everybody has their own decision about what to eat and what they prefer, so if you want to go higher please do, but don't think that it is going to be any safer. The choice of 130F as the bottom of their range was quite arbitrary on their part - it occurred because a meat processor wanted to make pre-packaged roast beef that wasn't grey, and this is the temp they asked for. The people resposible for the decision told me that a lower temperature could easily have been justified, and that they have approved lower temperatures on a case-by-case basis. The target organism for USDA/FDA tables is Salmonella, and it can be killed down to 120F (but it takes a long time). This is documented I would guess that the origin of the sour smell is very likely enzymatic reactions that occur while the meat is coming up to temperature, and then the flavors produced then sit for a long time in the bag. In fact, I bet that you had meat that a bit old and starting to go off prior to cooking. So I would bet that your problem is NOT the temperature, but rather the time it takes to come up to temperature. How thick were the pieces? How loaded was the bath? Once you get off flavors in the bag, cooking for 48 hours is likely to concentrate them and soak the meat in them. Acids produced by aging (i.e. rotting) include lactic acid, and if there was some in the bag at the start you will just soak the meat in them over a long period of time. Acid reactions with the meat can occur regardless of temperature. I bet if you took the same meat and cooked to a higher temp for the same time you would get the same smell issue. Searing the outside first is always a good move safety wise. Or if you don't want to sear, plunge meat into boiling water for 10 sec. I have done beef cheeks, and flat iron steak for 48 hours without any problem.

Alas, we kept getting ambitous, so no the book is not close to publication yet. We are working away - there is a team of 6 people working full time on the book. I don't have a firm schedule yet, but will certainly post to the thread when we do.

Beef cheeks are very tough beacuse cows chew their cud virtually all day every day. They need a lot of cooking to get tender. In traditional cooking they would be braised for 4 to 8 hours. In sous vide you have a wide range of choices for beef cheeks - from 130F/54C up to 180F/82C. I have not had success at 54C, but conciveably somebody would like it at that temperature. I would start at 140F/60C for 24 hours. Pork belly is pretty much the same story. It can be tough, and in addition there is a lot of fat that for most people's tastes needs to soften. Pure meat fat melts at quite low temperatures, but fatty tissue is held in a matrix of collagen and other tissue which needs a lot of cooking to soften and release the fat. Although you can cook pork belly at 130F/54C, most people would not like it like that. 140F/60C for 24 hours is a good start, but depending on the source of the pork and personal taste you might prefer 36 hours. 180F/82C for 8 hours is more like a traditional braise. You can do any combination of time and temperature that you want. Lots of people like to brine, or dry cure pork belly. In the limit you wind up with something that is essentially unsmoked bacon. If I want those flavors I generally just want bacon, so personally I prefer not to brine or cure the belly to that extreme.

Well, I didn't see the part in Under Pressure where it says meat has to be cooked to 60C. It is very hard to believe that the book does say that because French Laundry and Per Se surely don't follow that rule. So I am skeptical that this is the case. But, if it does say that then it is just flat wrong. You don't need to take my word, or Douglas' word for it - it's in the FDA and USDA documents. Last month I met in person with FDA and USDA scientists in Washington DC to discuss these matters at length. Plus I have read all of the technical information about it in the scientific literautre, and at least a dozen books on the topic. The unfortunate fact is that most of the food safety information that chefs and the public are taught are wrong. This situation persists primarily because in traditional cooking people don't worry about it very much - when you grill a steak everbody assumes it will be OK. When you cook the same steak sous vide, it is such a weird situation (like cooking for 24 hours at 55C) that it begs the question. Another factor is that various authorities propose lots of safety factors - so instead of telling home chefs the the truth, they exaggerate what is required "just to be safe" - assuming that the home chef is incompetent, doesn't have a thermometer etc. Many people have such a strong belief that the food safety things they were told are wrong that they have a hard time accepting what the actual scientific truth is. This leads to the strange situation where they can't accept the truth. A lot of posts on this thread document that - people will make their first post and say "but this can't be safe!", or express a similar fear. Saying that flat iron is a "steak cut" like fillet mignon is a bit weird for my personal taste. Try cooking flat iron side by side with fillet mignon and see what it's like! Flat iron steak is a relatively tough piece of meat if cooked for a short period, and is relatively cheap as a result (often less than half or even a third the cost of fillet mignon). If served as steak after quick cooking it is usually served sliced thin across the grain to make it possible to eat, and even then it is chewy. I have never seen a restaurant serve a quick-cooked flat iron steak whole (i.e. so the diner has to do all the cutting), the way steaks are typically served. Instead it is usually served cut up into slices and fanned on the plate. People would send it back otherwise. But hey, everybody has their own taste, so by all means cook it they way you prefer it! To my taste when cooked sous vide for 24 hours at 131F/55C it is a fantastic piece of meat. You can go longer if you like (I have done up to 48 hours), or if the beef source you have is particularly tough. You can go less - I have tried wagyu flat iron at 12 hours. Flat iron steak has a relatively high collagen content which is why it is tough, but that collagen then gives a unctious mouth feel when converted to gelatin by the long slow cooking.

One ostrich egg is about 18-24 chicken eggs, so yes, it is more than one person can eat....

Very cool that they sell them.... I don't think you need very many to experiment with. One good test will tell you most of what you need to know. I have not tried to cook one, but if they were available locally to me (Seattle) I would definitely try to cook one with a temperature probe in it. A rough calculation suggests that it would take about 5 hours to reach temperature on the inside, assuming you are going to cook it to 65C starting at 5C. The time will depend on temperature, but only within a small range (i.e. plus or minus 30 min in a roughly 5 hour cooking time). I suspect that the protein coagulation (i.e. cooking) will occur at tempertaures similar to chicken eggs. Quail, duck and goose eggs have very similar tempertures, so I bet ostrich would too, but of course that could be wrong. I have not tried one. The problem with ostrich eggs sous vide is that they are so big. 5 hours total cooking time translates into about 4 hours within the so-called "danger zone" temperature range. This is right at the edge of what is officially acceptable. I think that would likely be fine.

I need to find a supply of wood sawdust (or very fine chips) for smoking meats. I am particularly interested in oak, apple and hickory. I want to buy some large quantites - i.e. 50 lb sack - not the tiny little bags that are sold for use with home barbeques. Does anybody have recommended suppliers?

The latent heat of fusion for ice is 334 kJ/kg So, melting 475 grams of ice takes 158,000 joules of energy. Taking 475 grams from -20C to 54C is 146,000 joules. So melting the ice and bringing it up to temperature would require 305,000 joules. It takes 4.18 joules to change the temperature of 1 gram (1 cc) of water by 1 degree C. So if you just dropped the ice in without the heating element on, the temperature of a tank with 9 literes of water should drop 8 degrees C, by the time the ice was all melted. But you did have a heating element on, and 1 watt = 1 joule/sec. So, a 1500 watt heating element would take about 3.6 minutes to put 305,000 joules into the tank at 100% efficiency. The efficiency is probably no more than 50%, and the heating element probably was not on high heat the whole time because the PID controller was gradually regulating the heat to avoid overshoot. Remember that the PID only "saw" a 2C to 3C temperature drop, so it would not turn the element on to full power. The P parameter determines how the power goes proportionate to temperature difference. So, your result on the dropping the ice into the tank is reasonbaly consistent with all of this. If you could record the PID % power output it could all be calculated very closely. If you had dropped crushed ice in, you would have gotten a lower temperature spike on dropping it in. The ice brick took a while to melt, that is why the temperature was on a plateau for 15 minutes.

I am not sure why the difference between tests. Ambient temperature is ceratinly part of it. In both tests you are getting a very strong overshoot, which lasts for a long time. This is not right and is something that proper tuning parameters should eliminate. You should not get this level of overshoot. If you put an aquarium air pump and bubbler in to stir the water it will help. The air will be ambient temperature so that cools the bath down and will help reduce the overshoot. It will also stir the water around. This is only a partial solution because it looks like your PID parameters do need improving.

This is an important point - the amount of time it takes to autotune can be very long because it must go through a couple cycles of heating and cooling to measure overshoot and time response. If you change the set up (different heating element, different volume) you must retune. That is another reason to prefer continuously tuning PID controllers....

The reason to cook a sauce that long is to leach gelatine from the meat into the sauce, which adds richness and mouthfeel. You don't really need to tenderize ground beef, because it is ground. It might make some difference, but it could also fall apart. Traditional bolognese sauce used cubed meat which did need to get tender.

That is an interesting question, I'm not sure why most studies do not consider anything less than 135F/57C in eggs or poultry; . For an educated guess, we can use the D-values for Salmonella enteritidis of 4.5 min at 58C and 6.0 min at 57C in [J Appl Microbio 83 (1997) 438--444]. These D-values give a z-value of 8C (1/log_10(6.0/4.5)). Therefore, at 131F/55C it would take 6.5*6.0*10^((57-55)/8) + 35 = 105 min and at 133F/56C it would take 6.5*6.0*10^((57-56)/8) + 35 = 87 min (where the study found that the egg took 24--35 min to come up to temp). From Table 4 of the survey article [J Food Sci 71 (2006) R23--R30] (which includes many studies at 55C, 57.5C, 58C, ..., 70C for Salmonella spp in poultry), I compute a D-value of 4.8 min at 60C with a z-value of 6.46C. Thus, a 6.5D destruction of Salmonella spp is: 6.5*10^(9.97- 0.1548*55) + 35 = 220 min at 131F/55C and 6.5*10^(9.97- 0.1548*56) + 35 = 165 min at 133F/56C. However, since Salmonella enteritidis (which is the strain found in eggs) is a less thermally resistant strain than the Salmonella senftenberg containing `cocktail' used in most the studies, the times in the previous paragraph should be sufficient. Edit: Added extra detail. ← Amazingly enough there is no US government standard time and temperature for whole-egg pasteruization. I have asked pointedly and they can't find any, in part because of a bureacratic issue as to whether it should be set by FDA or USDA. The typical recommendation from both USDA and academic papers for whole egg pasteurization is 5D, rather than 6.5D. You might ask why, and I have done so without getting a good answer. In general the answer to these things is usually an arbitrary decision somebody made. In fact, there are so many arbitary decisions, and outright errors, in the FDA code that it is almost amusing. My book will have a big discussion of this. Typically the adacemic egg science literature is interested in shortening processing time, so they recommend the highest temperature they can use without denaturing the proteins in the egg (which would mean it wouldn't whip well etc.). As Douglas says, it takes about 25 min for an egg to reach core temperature (and this does not depend very much on temperature within this range). After that if you hold for the same times as the normal 6.5D table you will be more than fine. The standard 6.5D table is 112 minutes at 130F/54.4C. So, if you want 6.5D you should do 112 + 25 = 137 minutes (2 hours and 17 minutes) total cooking time at 55C/131F Or you want to do 5D, you could reduce the times to 25+ 86 = 111 min (1 hour 51 minutes) at 55C/131F

I don't think physics class would help that much. Changing the PID parameters is known as "PID tuning". It is a huge topic - I just found 289,000 hits in a Google search, including YouTube videos etc. There are dozens of books on PID on Amazon (and I have them all). It is not brain surgery, but it is an involved topic. Autotuning controllers do this for you automatically, which is very convienent. There are two kinds. The cheap kind has an autotune button or mode. As discussed in other posts it works best when the temperature is already stable. To use it, you read the manual, then put it in the mode and it will tune itself. Autotuning requires that the system perform some tests and determine how long it takes to heat up and so forth. It can sometimes be fooled as the post above suggests. The newer, and a bit more expensive self-tuning PID controllers will do automatic tuning at all times - instead of an autotune button, it just always watches what is going on and adjusts itself. In general these are much better, and when I use a PID controller I try to get one of these. However, I don't think that is the kind they use on SVM. Different PID manufacturers have their own terminology for the automatic tuning - some claim they use "fuzzy logic", others use a different term. In the case of immersion circulators or water baths, the manufacturer sets the PID parameters and you should never need to change them.

Isn't any sort of sv 'burger' (or other ground/minced meat product) a rather bad idea from the food hygiene standpoint? ← I would say not really, provided to achieve proper 5/6d reduction times maintaining an intact surface isn't really a concern. in fact given adequate temp and time, a sv burger would be considerably safer then a regular grilled burger. ← How does that work for Clostridium botulinum? Isn't that the major worry (in terms of seriousness of outcome) with any 'comminuted meat' product in a low oxygen, non-acid, environment at these 'warm' temperatures? And where the centre is not going to benefit from post-sv searing? ← My understanding is that botulism needs time to germinate and produce nasty toxins. I don't think you should cook and hold burgers or any ground meat, but if you grind some beef, make a burger, cook the burger and then eat the burger in the time it takes you to do this, I can't see it being a problem but I am not a micro-biologist. Also its not like you have to cook burgers low and slow, you just want to bring them to temp, they are already plenty tender. ← My understanding of botulism was similar - that you need a long time in a zero oxygen enviroment for it to grow and produce toxins... the FDA shows in the food code how long you can keep pasteurized ROP products at different temperatures.... From what I understand, if you do cook-chill, you can keep stuff at refrigerator temps (34F) or lower for a max. of 30 days (according to 3-502-12D(2)(e)(i)) So, theoretically, you can cook your burger to 55C for a time long enough to pasteurize depending on thickness, and then chill them down and refrigerate for a month - then just take out and sear on the grill to bring back to temp whenever you're ready... If you want to cook at lower temp. (for a really rare burger), I don't see why you couldn't do it, just so long as your burger wasn't 4" thick so that it would sit in the danger zone for too long.... then eat right away - can't store in the refrig. since it's not pasteurized.... Am I reading this correctly? Someone please correct me if I'm misunderstanding this.... ← Various pathogens die at different temperatures. The standards set by USDA FSIS (food saftey inspection service) and FDA (food and drug administration) are based on their overall judgement as to what people ought to do as a general rule. Their general rule starts at 130F/54.4C, and is based on research on Salmonella. However, Salmonella can be killed at much lower temperatures - there are scientific papers documenting Salmonella down to 120F/48C. The times for 120F/48C are much longer, and yes you can extrapolate them from the existing curves. You could also extrapolate to 122F or 125F. I have asked USDA / FDA officials why they start at 130F/54.4C instead of lower. The answer is basically that the standard was set for pre-cooked ready-to-eat roast beef (i.e. sold packaged in grocery stores). The industrial food companies that make it asked for 130F, because for that product they didn't need it lower. Nobody asked for lower temperatures. Once the standard had been set for that, then the FDA adopted it as a recommendation for other cases. There is no strong scientific logic at work here. So if you care about Salmonella, then there is strong scientific evidence that you can cook below 130F/54.4C if you cook for a long enough time. Other pathogens can survive at higher temperatures. Listeria is one, Clostridium perfringens is another. However, the general judgement is that the rule for Salmonella ought to be enough. It would be nice if general rules came with a gurantee, but they don't. If you have a horribly contaminated piece of meat, cooking it to the general rule - at any temperature - might not be enough. Conversely if you have uncontaminated meat, you can eat it raw. Carpaccio and steak tartare are delicious and with quality ingredients are MUCH safer than many things we do every day - like ride in an automobile. Ground meat is OK if you cook it so that the core temperature reaches the appropriate tempertaures for the appropriate amount of time as given by the rules/tables. Botulism is much feared, but it only comes from storing the food in a vacuum long enough to germinate. If you eat the food immediately after cooking, you do NOT need to worry about botulism. So it only applies to cook-chill sous vide. The lower the storage temperature the longer you can store it. at 34F/1C you can store a month. At 41F/5C a week. Again these are general guidelines, which match FDA 2005 Food Code.

Canning jars work very well for sous vide for cooking liquids. There was a post on this long ago on the thread. The jars won't have a vacuum, so the food will not keep as long as food in a bag, but that is OK for most purposes. Just fill the jar as full as you can, seal it, and put it in the bath. You will need to increase the time a bit because it takes time for heat to penetrate the glass jar - it is thicker than a sous vide bag.

Circulation in a water bath can be very important, but it is possible to live without it in some cases if you are careful. The point of circulation is to make sure that you don't get cold spots so there is even heating all over the food. The factors that make circulation more important are: - How big is the bath/pot? - How much food is in the bath/pot? - Is it clumped together, or spread out? If you have a large crock pot / rice steamer / roaster controlled by a PID it will work very well with it if you keep the food in the center, keep it from touching or clustering and have a good ratio of water to the amount of food. To prevent food from clumping you can use use things to separate it (cake cooling racks, mesh baskets made for deep fat frying...), either from other bags of food, or from the bottom or sides of the pot or bath. Or you can use binder clips to clip the bags to a rack you put over the top of the pot. Or magnetic clips for something similar. On the other hand if you jam it full of sous vide bags that are all touching one another you will not get even cooking. In fact, even if you do have a stirred / pumped water bath or immersion circulator you can overload it to the point where the stirring or circulation still does not prevent cold spots and uneven cooking. An aquarium pump with bubbler can do a reasonable job of forcing water circulation - it isn't as good as a circulation pump. It is OK for home use but don't crowd the bath. Make sure the bubbles are coming up on all sides - if you have a bubbler over in one corner of a large pot and there food blocking the flow to the other side of the pot, it won't do you much good. The bubbles are what stir the water so they need to be reasonably distributed. Some of the posts above talk about "water bath" and "immersion circulator" as two separate things. Laboratory water baths come in two forms - those with pumps which are basically indentical to an immersion circulator, but have a built in tank. They are also called "stirred water baths" but in reality it is a pump not a stirer. There are also "utility water baths" which are unstirred and have no pumps. The unstirred ultility baths are very simliar to an improvised outfit with a PID controller and a rice cooker, or roaster. In general water baths with pumps usually have better temperature control, and are more expensive. But generally they are worth it. Restaurants that do a lot of volume production really ought to use a bath with a circulation pump. Home users may also find it convienent if they do large quantities.

Sirloin can be tough. 3 hours is pretty marginal timing, particularly if it was thick. That said, there is no cooking techique that could render it tender in that timeframe unless you cook it to death, which of course you could do with sous vide also. If I had to cook sirloin that might be tough in 3 hours, I would still use sous vide. If possible I would jaccard it. I would make sure that it was not too thick (cutting it if need be) and then cook it at 125F/51C to 130F/54C, then sear. The key however is to plate it thinly sliced and fanned out. Or thin sliced as part of a dish like fajitas, thai beef salad etc. Regardless of whether you cook it sous vide, or cook it any other way, you aren't going to tenderize it in that time frame without overcooking it. So you need to deal with the toughness mechanically. Thin slicing and jaccard are about the only way to "tenderize" it in that time frame.

Eating raw wild salmon gives you a risk of anisakid nematodes. A reseach team investigated Seattle area sushi restaunts in the early 1990s and found that 10% of the salmon sushi they tested had live anisakid worms in it. Most, but not all of that certainly had been previous frozen so the worms were dead. Seattle does get a lot of fresh, unfrozen salmon. Other places do too. So not all salmon is frozen. It ought to be if it is going to be served raw, but often isn't. Many sushi bars, even very high quality ones, use frozen fish. Tuna is generally not a problem for anisakids, but for freshness and quality reasons it is often frozen - the Tokyo fish market is full of hard frozen fish. The main reason to use frozen fish is better quality - which sounds odd because most people think that frozen is worse. It depends on how the freezing takes and thawing are done - you have have extremely high quality fish that is frozen. Despite the risk, anisakids only rarely causes illness - as a previous post said 2000 cases a year in Japan is not that many. Even with 10% of Seattle sushi infected, people were not dropping on the street from anisakiasis in the early 1990s. Anisakid nematodes have been recovered from cold smoked salmon, and other smoked fish. Cold smoking does not get hot enough to kill the worms. FDA regulations hold that you are supposed to freeze fish before cold smoking for that reason but it may not always happen. Holding at 32F is not sufficient to kill the worms - you need a hard freeze.

Yes, Douglas puts it very well. The interior of intact muscle of virually all food animals is sterile from pathogens. Bacterial contamination is almost all external, and almost all fecal in origin. So, if you have a hunk of intact beef muscle - i.e. a roast which has not been stuffed or cut open, or larded, or injected, then as Douglas says, there is no problem cooking it pretty much however you want. To get a high load of C. perfringens in beef would be pretty hard to do. However if you did have a high load, AND you then follow FDA rules for what is "acceptable", then there is a limit of 5 to 6 inches. Even that is unlikely to make you sick because C. perfringens dies easily with heat. Its spores do not reproduce well until heat shocked to 70C (well above the temperature where any sane person cooks a beef roast). So even in this very unlikely case the application of the rules is misleading. But, just to be nit picky, with a high enough pathogen load, even that might not be enough. There is no "right" answer here. The fact is that intact beef muscle is virually always sterile, so in practice you can cook big roasts sous vide without difficulty. Yes there is some chance that you have the first case of non-sterile beef in history. Or maybe your butcher poked into the center of the meat with a knife that was dirty from cutting pork skin. On the other hand, maybe you get run over by a bus on the way home from the butcher shop - in fact that is statistically a lot more likely.

There is no other place for fat to be than in the meat or in the bag. So if it is not in the bag, it is still in the meat. Cooking meat at or above the melting temperatures does not necessarily mean that you will drain or render all of the fat out of the meat. Fat is bound up in fat cells. The fat cells are usually surrounded by other meat tissue. Melting the fat changes the taste and mouthfeel, (which is the point Douglas Baldwin was making) but even if melted it it can remain bound in the tissue. The most effective techniques for rendering involve fine chopping the meat and fat in a meat grinder or even a blender or food processor - for example here on recipe gullet. Mechanically breaking up the meat assures that the fat can leak out of fat cells. Of course that is for rendering. This approach defeats the purpose you seem to be after - which is rendering fat from meat that is still intact. That is best accomplished by either trimming fat away (before cooking, or on your plate), or cooking at even higher temperatures for a long period of time. However, this will create dry meat - indeed dry meat is exactly what you get after rendering. Removing a little fat is fine, but ultimately if you want rich beef taste with moist tender meat, there has to be some fat present. Finally, I will point out that brisket is actually not that fatty. There is a thick fat cap on brisket, but if that is trimmed away the remaining meat is actually quite lean. There is connective tissue in brisket - but that is mostly collagen and not very high in fat. In fact, this is one of the challenges in cooking brisket - it is easy to make it too dry.

depends on your meat - if it is very tender, then yes that is too long. Sirloin is probably tough enough that it will be OK, but you are taking a risk on that much meat - trying a sample first would let you know for sure... Jaccard-ing it first probably means you should reduce the time, but it depends on the meat and how tender you like it.

56C for long enough - try 48 hours, but might need 72 depends on the toughness of the cheeks

Waygu cheeks are fantastic - at least the ones I get in Seattle are great....

Yes, this works - I have done cheeks at 56C - needs 48 to 72 hours. Comes out great. tongue should be similar. Brining is to get the cured / corned beef flavor. Try it without first.