Robert Jueneman

It's been about 10 years since we remodeled the kitchen in our house in Provo, UT and I still miss it here in California. The star of the show was a big Viking gas cooktop in the center island, with the 24" griddle and four burners, with a huge range hood overhead -- rounded edges, not Viking -- maybe Thermador?? It had a huge 12" air duct, and a 24" fan mounted on the outside of the house. The grease traps were removable, and could be put in the dishwasher. I absolutely loved the range and griddle -- no problems at all. The grills could be dropped in the dishwasher, and the slide-out drawer caught all of the spills before they got baked on. 110% pleased, no, make that 120%. Two stacked Gaggenau electric wall ovens with pizza stone and rotisserie -- also 110%. After my mother singed her eyebrows with an explosion back in the '50's, I don't think I ever want a gas oven! The original cooktop (on the opposite side of the island from the sink???) I ripped out and replaced with a glass one -- I still HATE glass, after three of them -- but it gave me four more burners. There was a built-in microwave (good) with an integrated range hood (completely useless) over that cooktop. The dishwasher was a Bosch, and it broke a couple of times -- not so good. The side-by-side refrigerator/freezer wasn't big enough to hold all of the "refrigerate after opening" bottles and jars that seem to accumulate. Ideally, refrigerators should be about 9 inches deep, and about a mile wide. I certainly will never buy another LG refrigerator -- the one I have now has shelves that bow too much, and the water filter sprang a leak and ruined the carpet in the next room. I'm presently designing a house I hope to build in a year or so, and I plan to incorporate those lessons, plus some new ones: 1. There has to be room for at least two and perhaps three commercial 10 liter rice cookers and PID controllers for cooking sous vide. I'm not convinced the Poly-Science circulators are worth the extra money and space, but if I win the lottery, I suppose I could be persuaded. Because I don't relish hauling 10 liters of water around, I need a sink nearby so I can drain and refill them periodically, using a hose. An overhead shelf would hold the PID controllers, and separate 20-amp circuits for each cooker is essential. In fact, a separate electrical sub-panel just for the kitchen would be a nice idea. 2. In addition to the griddle and four burners, one or two of which must support a nice simmer, I also want a very high-heat commercial-grade wok ring and burner -- maybe 24,000 BTU? A built-in deep fat fryer would also be nice. 3. This house is going to be in the Sangre de Christo mountains of Colorado, at 8000 feet, and an outdoor barbeque isn't going to be practical for three months of the year -- maybe more. An indoor grill would be very nice. Maybe it could be combined with a wood-fired pizza oven, as long as I'm day-dreaming. 4. A salamander, and a warming tray for dishes, would also be very nice to have. 5. A commercial-grade rubber floor matt is worth thinking about, with a built-in floor drain. A hot-water or steam hose would also be nice, for clean-up. No wood or marble, this time around! 6. A spare bedroom, in case Alice Waters, Thomas Keller, or Alain Ducasse decide to stop by to go elk hunting. Douglas Baldwin, you are closer, and the door will always be open! Bob

Good point. P=180 (F) or 100 ©, with I=0 and D=0. The 50 and 75 values were for the 1500B, which I only use in Celsius.

Human Bean, mechanical oven thermostats are normally pretty easy to calibrate. You just pop the dial off, look behind it, and twist the gizmo until it reads right. Otherwise, your utility company is normally willing to do it for you. Nonlinearity may or may not be fixed with this procedure. Digital thermostats are a different issue. Bob

joesan, I hope I didn't insult you by defining my terms. I sometimes forget that on this blog, at least, there are probably more science geeks than cooks! And Martin, I agree that stability is more important than accuracy, assuming you do adjust for systematic error. However, if you are using your equipment over a broad range of temperatures, linearity may be even more important.

Having bought and tested about 14 different digital thermometers, I wouldn't trust ANY of them before I calibrated them. An ice bath is good for 0C/32F, and a basal thermometer for 38C/100F, but most people don't have an ingot of tin lying around (melting point 232C/450F)! And the boiling point of water is too dependent upon altitude and barometric pressure to be much of a help. Some infrared thermometers claim 1% accuracy, but that's 5 degrees at 500F. I've seen and returned units that were off by as much as 14F at 100F. Calibration services will calibrate your thermometer for around $100. Or you can buy a reference thermometer accurate to 0.1F and certified to NIST standards for around $300. For a really good one, you'll pay more than you did for your oven!

A fascinating series of posts, from all over the world. Peter, I won't say that the I value is useless, as I haven't exhausted all possibilities -- especially for smaller cookers. But I've tried I=1, I=10, I=100, and I=250, and all of them have resulted in excessive overshoot, and in most cases takes too long to stabilize. My previous tests with the 10 liter cooker showed that P=50 and P=75 produced too much overshoot, while P=100 produces maybe 1C overshoot, and P=200 takes too long to come up to temperature, so P=100 seems pretty close to optimum (with I=0, D=0). If you were cooking a small amount of something, e.g., a small pice of salmon, where he overshoot might matter, you ought to wait for everything to stabilize. But if you throw in a 500 g frozen steak, the overshoot would actually help. So far, I have not been able to eliminate about a 0.2 to 0.3C long-term undershoot with that combination of PID parameters and the 1500B. Of course, with the 1500A or 1500C, you would never see it. Maybe I'll just give up and change the set point. When you said an "ice brick" did you mean real ice, or one of those "Blue Ice" brick-like sealed containers? I'll be very interested to see the D values you come up with -- I'm going to be doing the same thing. Joesan, let me differentiate between four different terms: Resolution refers to the minimum observable difference in readings of settings. The 1500B offers 0.1C resolution. The 1500A and 1500C offers 1 degree resolution -- F or C, take your pick. 1C is too coarse for sous vide, at least to my way of thinking, but 1F is probably OK. Accuracy (in my terminology, at least) refers to the relatively short term repeatability at a single reference temperature. In other words, if the SVM displays XX.Y today, and I calibrate the offset to match my reference thermometer within 0.05C, will it display the same result tomorrow? So far, it does. As to long-term accuracy/stability, ask me in a year from now! Linearity (again, my terminology) means the difference between the SVM and my reference, across a wide range of temperatures. As I recall (I'm at work and don't have my notes in front of me), the 1500B had a linearity of plus or minus 1.5C from 38C to 85C, with the larger differences occurring at the higher temps. By contrast, the 1500C, which has a probe that is better at measuring higher temperatures but only offers 1F resolution, had significantly better linearity -- within 1F over the entire range. Its probe is also less likely to be damaged by very hot (boiling) water. Unfortunately, the 1500A/B probe is not interchangeable with the 1500C. So... To date I use the 1500B when cooking meat at 55.0 to 55.5C, because even 0.5C makes a significant difference in doneness; and I use the 1500C at 83C for vegetables, which (so far as I know) are not all that sensitive to the precise temperature. Would I like a device with a probe that was dishwasher safe, would withstand boiling as well as freezing, and would be accurate to 0.1C or better across the entire range? Yes. Would I pay $2000 each for two PolyScience circulators that would do that, if in fact they will (and I have yet to see any accuracy claims or test results that would substantiate that)? Not until I win the lottery! And now a question. Has anyone tried inserting one of the Taylor one-piece digital dial-type thermometers into meat, and then sealing the entire thing in the sous vide bag? I'm not certain whether the entire thermometer will withstand high heat, but it ought to hold up to 55C OK. Is there any obvious advantage in measuring the internal temperature, or are Douglas Baldwin's tables good enough? And wouldn't it be cool to have a probe with an integral RFID chip in it, for a remote readout?

Back to the overshoot question. My laptop is at work, so I can't run the data logger, but I tried my 1500 watt 10 liter rice cooker with my SVM 1500B (in Celsius mode) using P=100, I=100, D=0. The temperature climbed from 28C (well above ambient, but the water was still warm from last night) to the set point of 55.5C in about 10 minutes. Unfortunately, it kept climbing, and hit 59.4C 10 minutes later. 45 minutes after I started, it was still at 57.0. That's not very user-friendly, so we'll write off that combination. I assume my previous suggestion of I=125 for a similar cooker would produce comparable results. EDITED: After 1:20 minutes, it was back down to 55.3, or 0.2C below the set point, which is the problem I was trying to eliminate in the first place! EDITED #2 -- Now it's back up to 55.7, so it is oscillating, but not too badly -- unless it gets worse. So... what do we know? Assuming the cookers are reasonably comparable, I=100 is too low (it gets too hot too fast), but I=400 doesn't work either -- it may produce oscillations, and takes forever to stabilize. I guess I'll split the difference, and try I=250. If that still is ridiculous, I'll try I=1, and see what happens. And yes, e_monster, I will also try the auto-tune settings (P=13, I=900, D=300 -- as close as I can get by re-entering them), just to see what they do as well, even though they seem outlandish.

blackp, you now understand why I broke down and ordered the data logger accessory for my thermometer! Using a 10 liter, 1500 watt commercial rice cooker that is similar to yours, for Celsius measurements with the SVM 1500B I'm using P=100, I=0, D=0. With those settings, beginning at ambient, I find that things stabilize very nicely within 20 minutes, with no more than about 1.5C overshoot. With the SVM 1500A or 1500C, which offers 1 degree resolution, I use Fahrenheit for the improved precision. However, the SVM 1500B offers 0.1 degree resolution (Celsius only), so I've been using that for better control when cooking meat. With the above settings, the 1500B stabilizes at 0.2C lower than the set point, and never budges from there. Both the SVM and the reference thermometer agree at that point. Of course the easiest thing to do would be to simply change the set point, bu I thought I would try adding a little I value to see if I could tweak it a bit. I tried I=250, but after waiting for an hour noticed that the cooker was in the Warm position, rather than Cook. Stupid human! As I understand it, the fact that you are showing oscillations is a strong indication that the I value is too high. I read somewhere that if that occurs, you should set the I value to one half of the cycle time in seconds. If I can read your time line correctly, the period is about 4.2 minutes, so I=125 might be a reasonable starting point to try. But first, I would try I=0. This assumes you are not likely to add more than 1 or 2 kg of meat to the pot, or not more than 20% of the mass of water, in which case the water itself is going to do a pretty good job of integrating over time. Now, if you were adding that much to a small 1.2 liter rice cooker, that would be a completely different story, and then you would probably need a D value, but I haven't played with that yet. I've heard people say that the sensor should be touching the bottom of the unit, but I'm not sure I would agree. It would seem to make more sense to measure the water, rather than the bottom of the pot, which is almost surely going to be fluctuating every time it turns on or off and now you've got some crazy feedback going on. As far as cooking short ribs and other meat such as brisket or chuck for 48 hours, I think you should wait until things stabilize, or add some cold water if necessary. The long time is to dissolve the collagen, but an hour or even a half-hour (depending on the thickness) will be enough to cook it to medium, rather than medium rare or rare.

Cooking Vegetables I think I have a reasonably good understanding of the science of meat cooking, the opposing forces at work, and why sous vide gets such great results. But I really don't understand what happens when you cook a vegetable, and what the time/temperature relationship is. Why do some vegetables require 185 or even 195F, while others are best at 165F (at least according to Thomas Keller). How long would it take to "bake" a sous vide potato in a 131F bath? Would it work at all? I assume the same issues regarding pathogens would still apply, as they do in meat?

Nathan, thank you for your always informative posts. When I initially ran the autotune function on my SVM 1500A overnight with a 1500 watt, 10 liter commercial rice cooker, the resulting parameters were P=15, I=998, and D=499. Now, that means that it is going to put out full power until it is within 1.5F of the target temperature, and then integrate and differentiate the results to the max. Because the results were so far to the extreme, I simply discounted them as not realistic, and didn't actually try them. I was about to re-enter those values and try them, but I can't! The maximum setting I can enter manually for the I value is 900, and the maximum setting for D is 300. Strange. I'm about to go buy a USB to RS-232 adapter for my data logging thermometer -- the Belkin unit I have won't work with my Vista laptop because of driver issues(??), and running XP under VMWare on my Mac Pro is too much bother. But I should be able to automate some of this testing this weekend. BTW, to the best of my knowledge, the Sous Vide Magic and the Auber units are identical except for the name, although there may be internal differences. e_monster, when you calibrated your Auber unit, what type of rice cooker were you using, and how large was it?

Quis custodiet custodiens? Who shall watch the watchers? How do you know your Thermapen is accurate, short of sending it in to a professional calibration facility? One relatively simple way is to check it at the triple-point of water (ice bath) (32F/0C) using distilled water for the water and the ice. Then, to check linearity, use a $17 basal thermometer at 100 degrees. It should be accurate to 0.1F. But what it does at 131F, or 185F, much less at 400F, may be a completely different issue. IMHO, the Thermapen is good enough for home sous vide use, but I'd like to see something better for professional use.

Next time try mushroom risotto, with mushroom stock and chopped or sliced mushrooms. The mushroom stock is made with porcini or other dried mushrooms plus fresh mushrooms, to give it more oomph. Fabulous, unctuous, delicious, lots of other "ous" adjectives, and a meal in itself, and it doesn't even need the parmesan. But my ongoing education in rice continues. What is carnarolli rice? I use arborio for risotto. Also, would soy sauce be an acceptable substitute for Worchester for the non-pagans? Or does it contain fish as well?

blackp, I am working with Frank Hsu at Fresh Meals Solutions (source of the Sous Vide Magic) to put together a guide to tuning the SVM. I was all set to fire up my data logging thermometer tonight, as a matter of fact, but I realized I first have to find a USB to serial port adapter -- I no longer have a computer with an old-fashioned serial port. Here are my initial suggestions, but they are primarily based on my experience with the large 10 liter rice cooker, instead of my 1.8 or 1.2 liter Tiger and Ikeda units. First, forget the Autotune function -- it seems to come up with some rather bizarre settings, at least for the large pot, even after running all night. Instead, first determine an approximately optimum P (proportional) setting, with I=0 and D=0. I would try the settings in the instruction book first, and then experiment from there. At least initially, start at ambient temperature, and record and plot the temperature of the bath (preferably using an external thermometer with 0.1 degree resolution) every 30 seconds for say 20 minutes. If the overshoot is too great, the P value is probably too low. As a result, the SVM is putting out full power until the unit is close to the set point temperature, and at that point the trapped heat makes the device go into overshoot, even after the power is essentially off. Then, because rice cookers are well insulated, it takes a long time to drop back down. On the other hand, if there is relatively little overshoot, but it takes forever to come up to temperature, the P value is probably too high. I don't know that I would cut it in half -- that might be too much -- but cut it substantially. It should then go into overshoot mode, and by increasing or decreasing by 1/2 of the difference each time, you should be able to optimize the P value fairly quickly. (Of course, one good way to simplify this entire process is to add preheated water of approximately the right temperature to the pot to start with!) If the final result, once everything has stabilized, is an undershoot, then you may need to adjust the I value. So far, with the large pot, I haven't found the need to do this yet, but if you check out "PID controller tuning" on Wikipedia, you will find some suggestions. I THINK that the best way to do this is to apply a massive increase to the I value, in which case the system probably ought to start oscillating -- swinging back and forth slowly from a minimum to a maximum and back. Once that happens, record the period, i.e., the amount of time in seconds between two successive minima or maxima, then divide by two, set the I value to that., and experiment from there. I'm not even close to determining an optimal way to set the D value, mainly because the amount of food I add to the water bath is small compared to the 10 liter mass of water, and things stabilize fairly quickly. But my plan is to take a set of "Blue Ice" bricks from the freezer one at a time, drop them in the water, plot the response, and tweak accordingly. If Douglas Baldwin or other mathematician or process control engineer can suggest improvements to this procedure, I would certainly welcome their insights. Once we get some better data for a number of different cookers, Frank has promised to post the results on his web site. BTW, I assume, with no personal experience to back me up, that using a circulator, an electric turkey fryer, or similar device that has the heating element directly in the water along with a circulator would simplify this process, except perhaps for optimizing the response if you drop in some colder food all at once. Note added: I've just been informed that the topic re sous vide thermometer accuracy has been relegated to the Kitchen Equipment section, at http://forums.egullet.org/index.php?showtopic=123336. (Why, I don't know.) In addition to tuning your PID controller, you really need to confirm the accuracy of the controller, so please reference that thread. Bob

Tomdarch, your points are very well taken. I'm neither a chef nor an attorney (although I sometimes play one or the other on the Internet), but I hang around with enough attorneys to vociferously agree with you. In our litigious society, if someone gets sick, they are going to want to sue someone for making them miserable, and if their last or at least most memorable recent meal was cooked sous vide, that will be an obvious target. The plaintiff's attorney will undoubtedly have a field day with sous vide in any case, as this will be seen as new, experimental, and "risky" to a carefully selected jury that prefers well-done beef. They will bring in "expert witnesses" who will recite the USDA guidelines, even though their witnesses probably have no training in either microbiology or food science. Having an approved HAACP plan will go a ways towards diffusing that issue, but you will have to be prepared to PROVE that you actually follow the procedure. At a minimum, I would recommend at least a weekly check of your working thermometers and any circulator baths against a reference thermometer -- not because I think that thermometers will vary all that much in such a short period of time, but just to show due diligence at an exacting level of perfection and precision. All such records should be prepared in ink, recorded in a permanently bound record book, signed by the person taking the measurement, and perhaps witnessed if you want to be ultra careful. A signed printout from an automatic data logger would be even better. Periodically, at least once an year and preferably twice a year, the reference thermometers themselves should be sent back for calibration. The calibration lab will record what the accuracy of the device was as received, and they will then adjust the device (if possible) to make it even more accurate. For the casual home sous vide enthusiast, $300 for an occasional-use reference thermometer may seem like an outlandish extravagance, and perhaps it is. After all, if your spouse or kids gets sick, they aren't likely to sue you. And if you get sick, you certainly aren't going to sue yourself, right? But if you would like to be sure that you know what you are doing, they you aren't endangering your loved ones with a low-cost thermometer that may or may not be accurate, and that this cutting edge stuff is in fact safe, then this may be money that is extremely well spent.

I checked with 99 Ranch and Lions (two large Asian grocery stores here in Milpitas, CA. 99 Ranch said that they were sold out, and didn't know when they would get any more, but suggested I try a Korean grocery store. Lions had never heard of it, but had some pickled garlic. I thought about it, but decided to pass. I did find wandering through both stores a cross-cultural educational experience. In addition to all of the fresh fish, clams, mussels, etc., that would be almost unobtainable elsewhere, I have never, ever seen fresh goal meat for sale! Anybody got a good recipe for goat meat?

I recently had a problem with the All-Clad unit. it seemed reasonably accurate above room temperature, but when I tried to re-calibrate it in an ice-bath, it wouldn't read below 60F! I exchanged it at Williams-Sonoma, and the new unit seems to work reasonably well. My unconfirmed suspicion is that that you shouldn't submerge the entire probe in water, but only the metal-clad tip. The instructions are far from clear -- it says not to put the entire unit in the oven(!), or in the dishwasher, but it does not say whether it is safe to immerse the entire probe. In any case, henceforth I am not going to. In the past, I have tested a number of thermometers at 100F, using a basal thermometer. I still think that is a good check point, but I was moderately encouraged by the accuracy that I got with five different thermometers at 130F or 55C, when compared to my Traceable 4000. All were within 1 degree F, and most were within 0.6F, after having weeded out the ones that were grossly wrong. The most recent All-Clad T201 was off by -0.6F at 131F, whereas the cheaper Sur la Table unit was off by -1.3F at 32F, but only -0.2F at 131F. All in all, if you are serious about sous vide, or if you are running a business where people's health might be at risk, spending the money for a NIST-traceable reference-grade thermometer to periodically calibrate your water baths and other thermometers would be a wise investment.

e-monster, I can understand that might be convenient to throw some eggs into the water bath while you are SV'ing some steaks. But whether you use 135 or 140F wouldn't seem to matter much -- at the end of the evening, while you are cleaning up, etc., or at the beginning of the day before the guests start to arrive at your restaurant, jack up the temperature by a few degrees, cook 5, 10, or 20 dozen eggs -- whatever number you think you will need for a day or two -- for 1:15, then chill them and save them for use throughout the day. I am neither a microbiologist nor an attorney, but if I could offer some strictly layman's advice, if something doesn't make a whole lot of difference to you, you are far better off following "conventional wisdom" in case a law suit ever materializes. Now, if this is just for own personal use, you can consider the odds that an egg is infected (1 in 10,00 to 20,000) vs. the likelihood you will be struck by lightening, or a bus, or by an enraged deer, or a jealous husband, or die of a heart attack or stroke, and decide for yourself whether it is worth worrying about. Obviously if you have AIDS or TB, are on chemotherapy, are pregnant or elderly, or otherwise might be immune compromised and more vulnerable than most, you should adjust your behavior accordingly. Bob

slkinsey, You are asking the right kinds of questions! No, there is no way (that I know of) to test the accuracy of the probe itself. I used the probe that came with the individual SVM controllers, and read out the reading form the display. I used the Sous Vide Magic PID controllers to bring a 10 liter rice cooker full of water to the desired temperature, then waited until everything was stabilized. I used a submersible garden fountain pump within the rice cooker to make sure everything was circulating nicely, and there were no dead spots. Since the Traceable 4000 has a read-out resolution of 0.001F, it was easy to tell that everything was quite uniform once everything stabilized -- within 0.01F at least, throughout the cooker. I first brought the temperature up to 131F/55C, and then adjusted the offset of the probe/SVM controller combination in accordance with the instructions. This was to establish a basic accuracy point, so that I could then measure the linearity (deviation from the Traceable 4000's reading) across the temperature range. The reason for selecting 131F was that it is the lowest you should go and still assume meat is being adequately pasteurized. A degree or two error at that temperature could potentially end up making people sick. However, now that I think about it , establishing a basic accuracy point of 100F might be a better practice, because 100F is within the range of the most accurate yet inexpensive thermometer most people are likely to have -- a fever thermometer, or better yet, a basal or ovulation thermometer, which should be accurate to within 0.1F. The only other calibration point that might be reasonable available for people would be the triple-point of water (32F/0C), as measured in a slurry of distilled water and ice made from distilled water. When using this technique, it is important that you keep pressing down on the ice to eliminate any water-only at the bottom of the thermos or other vessel, but at the same time, the mix must not be just ice. Unfortunately, the SVM controllers don't seem to like such cold temperatures, so you will have to calibrate another thermometer, and then calibrate the SVM at say 40F. One of the best, affordable thermometers I have found is the All-Clad T201. It reads to 0.1F, and has a Self-Set calibration button for use with an ice bath. if you calibrate that unit at 32F, and also at 100F and find the 100F setting to be reasonably accurate, you are probably OK within the meat-cooking range. However, even the All-Clad was off by 2.2F at 150F, and 1.5F at 185F. Dougal, although I haven't read any of the HAACP standards, I certainly HOPE that they call for periodic calibration of thermometers and/or circulators using NIST-certified reference thermometers. In my experience testing over 10 digital thermometers, I wouldn't trust ANY of them without calibration, as I have seen as much as 14F errors! BTW, the cost of the Traceable 4000 without the data logging software and cable is only $305. I realize that seems like a lot, but not when you compare it to a PolyScience circulator or a chamber vacuum! Please, everybody, if you are going to cook sous vide, and post recipes as to what you did, at least spend the $17.98 to buy a basal thermometer, and perhaps a couple of bucks for some distilled water for an ice bath.

Sous vide problems. Today was not a good day! First, I had problems yesterday with my FoodSaver suddenly not pulling much of a vacuum. It turns out the lower gasket was torn somehow. Solution -- order two replacement gaskets ($3.00 each from FoodSaver, plus a upgraded FoodSaver (what appears to be a very nice unit -- the Professional III, with five different vacuum settings and other goodies, all at a very nice 25% discount), plus five boxes of quart bags (also discounted), plus second day air shipment -- total $345.66. Ouch! Lesson learned #1 -- order spare gaskets and other spare parts ahead of time -- they are rather fragile. Second, two different probes failed on my Sous Vide Magic 1500A and 1500C, and unfortunately they are not interchangeable. Although the probe wires are thin enough to allow my rice cooker to close on them, apparently they have somehow gotten kinked or broken. One doesn't work at all, and the other is erratic, with temperatures vacillating plus or minus 20 degrees F. Damn! I'm going to order two replacement probes tomorrow, and maybe a spare or two, and then I'm going to encase the probe wires in poly tubing to protect them. If the lid won't close completely, that's too bad, but I'll live with it Lesson learned 2 -- protect any external probes from damage, and keep a spare or two on hand if you have gotten used to preparing all of your meals sous vide, or if you are running a restaurant. A couple of days ago, the power went out (just on our block), and so at 8:30PM we gave up and went to the Elephant Bar in Fremont, CA. I ordered lamb shanks, but was very disappointed, as they were too well done, and covered with a too salty sauce that tasted like an old pot roast. "I can do better than that," I said. Wrong! And thank you, darling, for not being so unkind as to remind me of my brave words. Cooking two lamb shanks at 55.5C/132F for 24 hours left the lamb moderately tender, but not quite not melt-in-your-mouth, and probably too rare, even for my taste, with barely enough meat to make it worth the effort. Scratch that idea. Cooking tiny carrots sous vide for 30 minutes with a little orange marmalade and butter revealed the fact that the carrots had probably suffered from freezer-burn, and tasted a little off. Mediocre. Note to self -- need bigger, fresher carrots. The tiny "Tipsy" cocktail onions soaked in vermouth, SV with butter and a pinch of salt and later glazed on the stove were better -- perhaps the hit of the meal. Not quite a disaster -- so far we are still alive -- but certainly not up to par. Sigh.

Douglas, thanks for responding to this thread! I'm happy enough cooking and serving beef at 131F/55C, and I don't particularly want to wait 2 hours before serving it, either. (24 or 48 hours is fine, however.) But I'm not a microbiologist, and so I don't know what C perfringens is, how hazardous it is, or (especially) how common it is and how it spreads. As I understand it, this should only be a problem if you cook-hold for more than four hours, correct? Would this risk be significantly reduced if I were to grind my own burger meat, and freeze it promptly and quickly, so as to reduce the possibility of outside contamination? I suppose I could even pre-sear the outside before grinding it, if that would help significantly. To change the subject slightly, when cooking lean burgers (12% fat, according to Costco) they are coming out rather dry, yet only a little liquid is left in the bag. Would letting the burgs rest for 10 minutes or so help to reabsorb the juice, or do I need to switch to ground chuck or something that is a little less lean?

Mallet, I saw some at 99 Ranch (a large Asian grocery store in Milpitas, CA) over the weekend. I didn't know what it was (like half of the stuff in the store), but now maybe I'll go back and try some.

Howsmatt, I can try to answer your four recent questions. 1. I can't speak to immersion circulators, as I believe they are overkill for most applications, unless you have a large restaurant and are really doing volume cooking with an extremely large one. I'm using a 10 liter rice cooker with the Sous Vide Magic (SVM) PID controller from www.freshmealssolutions.com. The 20 liter rice cooker is way larger than I personally need for the two of us, but there are 24 liter (and perhaps larger) rice warmers that are relatively efficient, and use only only an 85 watt heater. They won't bring the water up to a temperature, at least not quickly, but they will hold it there. So you should fill it from your hot water line, and perhaps top it off with a tea kettle, to bring it up to temperature. For the difference in money, you could buy four rice cookers with SVM controllers for the price of one PolyScience circulator, and have one for medium rare, one for medium, and one for medium well, plus one left over for vegetables or whatever. 2. For brisket, try 48 hours, rather than 24. It will make all of the difference in the world in terms of tenderness. Been there, done that. Note -- that wasn't a corned beef brisket, which seems to be more common in grocery stores. 3. I'm sure that Thomas Keller would roll over in his grave at the thought (so to speak, as I certainly hope that St. Thomas is still alive), but I have been doing hamburger sous vide for a month or so and loving it -- had it tonight, as a matter of fact. (Perhaps I'm not the greatest backyard chef, especially when the wind was blowing 50 mph and the temperature was below 50F, even here is balmy San Jose when the power went out last night -- its tough to cook sous vide with no electricity! But I digress.) My grilled hamburgers were never consistent -- too tough, too rare, not juicy enough, etc. With sous vide, you can control those factors one at a time. Currently, I'm using 55.5 C on my Sous Vide Magic 1500B for about an hour and a half for burgers that are about 20 mm thick, and according to Douglas Baldwin's table 5.8, 1:37 should be sufficient to pasteurize beef for a 6D reduction of Listeria. Since we used to eat steak tartare, albeit 40 years ago, that doesn't seem unreasonable. For a restaurant, I might add another 30 minutes or so, and I might also grind my own meat, and add some onions into the grind while I was at it. 4. If you look at St. Douglas's tables again, 5:14 is enough for even a 70 mm thick piece of meat at 131F, vs. 4:26 at 136F. I cook my steaks at around 131 because my wife doesn't like really rare roast beef, and it isn't worth firing up two SVM systems (although I now have three -- a 1500A, 1500B, and 1500C,. and three rice cookers of varying sizes from 1.8 liters to 10 liters). So if you are talking about 127.5F, extrapolation would suggest that another 38 minutes (5:52) would be more than enough, even for the thickest steak or brisket you are likely to serve to an individual, and 40 hours is way over the top. (This assumes you aren't picking up exotic bacteria from undersea lava vents or the pools at Yellowstone, or from Mercury or Venus.)

There's just the two of us, so nothing particularly fancy, plus I REALLY need to do my Income Tax! I'll carve my OMG brisket recipe (48 hours at 132F) like a London Broil, fanned out from the center and topped with veal demi-glace and sauteed mushrooms, maybe sprinkled with a little finely-chopped fresh rosemary. (I planted a tiny rosemary plant between the cherry trees in the the backyard about six years ago. Apparently it was ideally suited to the climate here in Silicon Valley. It now looks like a mid-sized brontosaurus!) The side dish will be Mushroom risotto made with home-made mushroom stock. Hot rolls with butter and lingonberry jam. I have about five kiwis in the refrigerator, so maybe some kiwi daiquiris to start off the dinner, and kiwis and strawberries for dessert. Bob

I just accuracy tested the newest Sous Vide Magic ID controller, the 1500C from Fresh Meals Solutions, using my $500 Traceable 4000 data logging thermometer from Control Company, which is calibrated to NIST standards to within 0.1F. The 1500C uses a new probe which is advertised as being more accurate at higher temperatures, and that proved to be the case. Out of the box, with no other offset calibration, the 1500C was accurate within the 1 degree F roundoff error throughout the sous vide cooking range of 100F (very rare salmon), 131F (a nice medium rare for beef and lamb, at least to my taste), 148F for the perfect egg and perhaps for pork (although 155 might be better, at least for most people who don't care for pink pork), to 185F (asparagus and other vegetables). (The first three temperature settings are actually quite demanding as far as sous vide accuracy is concerned -- certainly 2 degrees F will make a readily observable difference. It might not spoil a dish, but it is the difference between perfection and being merely acceptable. I haven't cooked enough vegetables sous vide to know how important absolute accuracy is that the upper ranges, but I suspect it is equally important, although perhaps less observable, at least directly.) The slightly more expensive 1500B (Celsius only) controller offers 0.1C resolution and was exactly right at 55C, 0.3C low at 38C and 0.4C high at 65C, but was off by 1.1C at 85C. I plan to use the 1500B for cooking meat sous vide, the 1500C for vegetables and other foods requiring higher temperatures, and the somewhat less accurate (in an absolute sense, at least without calibrating it to the specific temperature range to be used) but still quite stable 1500A whenever I need a third unit for some reason. If anyone has tested the accuracy of the PolyScience or Grant immersion circulators with a NIST-certified accurate thermometer, I'd be very interested in the results. They provide specifications regarding the tightness of their controls, but they don't cite their accuracy or repeatability. And without knowing the accuracy of the measurements, I don't know how to interpret someone else recipe recommendations. Sous vide is all about precision, but unfortunately, out of 10 or more thermometers, most are rather inaccurate -- at least if used across a wide range of temperatures. What kind of thermometers are professional chefs using to calibrate their equipment, and how often is that being done?

For cheap rice cookers of limited capacity (1.8 liters or "10 rice cups," which doesn't seem to have any correlation with any other form of standardized measurement I have found), the plastic shell 500 watt Ikeda (made in China, although a Japanese name) costs about $21, whereas the 650 watt stainless steel Tiger (Made in Japan) of the same nominal capacity cost $145 but looks more "professional" and might be more durable. The Ikeda is marked "For Home Use Only," whereas the Tiger is not. A Chinese "50 bowl" (another rather ambiguous measurement) 10 liter 1500 watt apparently well-made and well-insulated commercial rice cooker/warmer made by the Tar Hung Mfg. Thunder Group, Inc. cost me $185 (marked down from $240) in a Chinese restaurant supply store in Milpitas, CA. I have seen a 22 quart electric powder-coated black "turkey fryer" with mechanical controls that would be suitable for sous vide, for $79 at www.masterbuilt.com. They say that you can store oil in it, but not water (I suppose it might rust). There is also a 28 quart stainless steel version for $145 but it might have to be modified to disable the digital controls for use with a PID controller (probably not hard, for anyone with a soldering iron). The bad news is that these fryers aren't insulated and therefore won't be nearly as energy efficient as a rice cook for slow, low-temperature cooking, but the good news is that they are almost surely easier to control, with less overshoot or undershoot, because of their lack of insulation.