Guy MovingOn

Yes, but in my example, I did neither a pre, nor post, sear...

Those are some points which I haven't considered. There is a pet shop a few minutes away which seems to sell some aquarium accessories, so I will see if they sell a bubbler. I haven't really seen them in use, but just from their name I didn't expect them to be so effective. I will definitely check it out. Yes it could be an issue that I like my beef to be very rare, but even from the photos they meat wasn't particularly pink. Also it was rather dry on the mouth feel. It might be the particular breed - I don't know how Aberdeen Angus brisket compares to others, whether it is already more tender and the 48 hours was excessive? But the duration doesn't explain the colour so much. I will attempt to check the variance in my bath maybe tomorrow if I have time.

Air stones are quite effective for things like rice cookers and tabletop roasters (probably anything whose heat source is not in a concentrated area) as long as there is space beneath and above whatever is being cooked. My waterbath has heating elements on 3 sides, which apparently improve convection currents. Do you think in my situation an airstone would benefit? As PedroG noted, my waterbath is a bit shallow (15cm from the base to the waterline), but there is always some space beneath the bags for water to circulate. Cheers

Yes, I was actually quite surprised at the accuracy... but then wondered why there would suddenly be an offset of 0.2C above 41C. I suppose the next thing to check would be the variance inside the bath with unstirred water. Either that, or I just find a method of forced circulation.

Thank you for your suggestion. Yes, from the top of the waterline to the base of the bath is approximately 15cm. I do occasionally use a skewer to keep things in a vertical position, or use some of the excess plastic from the evacuated vacuum bag anchored underneath the waterbath lid to keep the food in an appropriate position. My waterbath also came with a metal grill which has about 2cm clearance underneath, so that incase an item was to sink to the bottom of the tank, it wouldn't sit against any heaters, and would also allow currents of water to pass beneath it. However, I would be interested in an effective method of forced convection in water of a temperature up to 80C. I know people suggest air stones... but how effective are they at regulating and circulating 7 litres of water to be at complete uniform temperature??

Ok, so I did some tests comparing the waterbath's thermometer to the Medisana Fever thermometer. The results are as follows. The water was stirred for approximately 10 seconds before the reading was taken so that there was an even temperature in the waterbath, since I am trying to ascertain the waterbath thermometer's accuracy and not the waterbath's ability to keep a uniform temperature. Of course there could be a variance of water temperature inside the bath. The only real discrepencies happen at above 41C, with a offset of about 0.2C, which is not present at any temperatures lower than 41C. Waterbath Fever thermometer 32.2C 32.2C 32.5C 32.5C 33.0C 33.0C 33.5C 33.5C 34.6C 34.6C 35.6C 35.6C 36.0C 36.0C 37.1C 37.1C 38.2C 38.2C 39.1C 39.1C 40.0C 40.0C 41.1C 41.1C 41.5C 41.8C 41.8C 42.0C 42.5C 42.7C 42.9C Too hot I also don't think this is a relevant issue, but just to note, during this experiment these temperatures were taken with the waterbath's lid off, and in normal operation, the lid would be placed on. I don't think this is particularly relevant to the thermometer's accuracy... but could help explain the temperature variation inside the bath.

I am attempting to confit pork belly. I saw earlier in this thread a suggestion of 80C for 12-16 hours. Any suggestions?

One key type of rancidity comes from exposure to oxygen. This is why anti-oxidants are often used to delay the onset of rancidity. If the fat is in a vacuum-sealed packed bag it is highly unlikely to develop oxidative rancidity. Opening the bag is likely to let some oxygen in no matter how careful you are. For this reason, I would not recommend this action. I thought this might be the case, since the rancidity is an issue in traditional confit, which I had an inkling may be negated by cooking in a vacuum bag en sous vide! Also the more I read about the confit technique, the greater variety of dry rubs, and recipes that I come across. I think there is a certain element of freedom. The confit technique started out in like C15. French farmhouses as a preserving technique, and I'm sure every family had their own recipe etc. I'm sure it's just a person preference. However, having the scientific knowledge of how fat cells cannot penetrate the flesh of the meat, and other such info, can help us to refine our technique/recipes. Yeh... don't think I actually said anything meaningful there... but it's great how we can all contribute to each other's understanding... especially about a technique such as sous vide

I'm still in the process... have done from 32C-38C so far... the fever thermomete has shown EXACTLY the same temperature as the laboratory water bath. My thinking is that the waterbath is unstirred. I have noticed that the laboratory waterbath has been showing 0.2-0.5C cooler before stirring the water and after. So actually before stirring the water, the water is hotter than it realised. PERHAPS this effect can be amplified whilst there is food in the waterbath too? Also perhaps the reservoir inside is 7 litres, which is perhaps not enough water compared to the volume of meat? These are just my ideas. I'm still going to go up to 43C, but so far I get the impression that the waterbath's thermometer is accurate, but its just limited by poorer convection currents, causing a 0.2-0.5C variance.

I bought a fever thermometer today with a 0.1C digital resolution. It is by a company called Medisana, and cost £6.99. The manual says that is has a temperature range from 32-42.9C. If I take readings at 32,33,34,35,36,37,38,39,40,41,42,42.9C according to my laboratory waterbath and compare the results, this should provide enough information to check for temperature offset and then calibrate for higher temperatures, right? Otehrwise I guess I could do readings every 0.5C too, but not sure if it is worth the extra time and effort...

Traditional duck confit is usually salt-packed for a few days before being cooked. That will carry spaces into the meat(those molecules are smaller than fat molecules and can transport well especially since salting apparently causes some relaxation of the muscle fibers). So, I would recommend doing the same. Coat the meat with your salt and spice mixture and cure it in the fridge for 24 to 36 hours. Then wash off the salt and bag the meat with a few tablespoons of fat and you should be good to go. There is no harm in having extra fat -- it just doesn't have any practical impact. I followed that process, but I saw a recipe where a bay leaf and a few other spices were placed in the fat when doing the traditional confit too, so I wanted to replicate that process in the vacuum bag. Anyway it was just my experience that with 1.5tbsp of fat, the whole duck leg wasn't coated. The duck fat can also serve another purpose. People say that the duck juice/jelly that results in the bag from duck confit should be discarded or removed from any duck which is going to be stored, since it could potentially go rancid (not sure if it is quite as relevant in a vacuum bag...). When there is fat in the bag, you can snip off a corner of the bag and drain the juice, without exposing the duck to any oxygen. Anyway, the amount of fat doesn't seem to be much of a big deal...

I'm inspired by the recipe book Charcuterie, and would like to try their version of deep fried pork belly confit, en sous vide. Could anyone suggest a temperature/time combination to confit pork belly please? Many thanks!

Yes I understand that laboratory equipment would still need to be checked and calibrated etc. My point was that at the moment, it is probably the most accurate thermometer I have. I did not mean to imply that I implicitly trust it to be 100% accurate. What I gathered from reading this thread is that 54.4C is the FDA's food safety temperature, and not the actual temperature at which food is safe to eat. In theory, an intact muscle, which has been either surface seared and bagged, or bagged and dunked in boiling water for at least 30 seconds, or both, and then cooked above 49C is THEORETICALLY safe to eat... but PRACTICALLY it is not feasible to do so due to the high risk of cross contamination and also fluctuating temperatures inside the bath etc. The reason why I wanted to try 52C is that the 3C would allow for some temperature variation and fluctuation in the bath. Once my bath is up to temperature, I never see it fluctuate by more than 0.5C at maximum, BUT, that is according to the laboratory thermometer which is built in, and I haven't had a chance to calibrate/cross-check. I think this question was posed to Nathan before, who said that whilst it is possibly ok, it is probably not worth the risk. I also didn't suggest that food could be pasteurised below 55C. I don't know at what temperature c perfringens dies, but would be interested to know. I understand the seriousness of food safety, and the closer I get to the border of safety, the more prepared and well-equiped I need to be. I am in that process, but funds are limited to give me the best (and safest) set up possible. I understand that during this time it would be advisable to stick to FDA recommended food safe temperatures, or cook at these somewhat questionable temperatures and consume in less than 4 hours from removal from the fridge. I also understand that a lot of you guys have to be ultra-cautious since you are either serving this food to paying customers, your children/wife/family, and need to support yourselves during the week due to your occupation. Of course, that doesn't mean I want to kill myself with food poisoning! But, you guys are all extremely helpful and caring, and I really appreciate all the advice and information!

I put around 1.5-2 tbsps of duck fat in the bag with each thigh, and I actually didn't think it was enough... As an fyi, it makes no difference if the fat is in the bag with the duck or added after cooking. Nathan did double-blind taste tests and found that it doesn't matter -- and there is reason. Duck meat is relatively dense and fat molecules are very large. So fat can't make its way into the meat. The mouth-feel is entirely the result of the fat that is coating the meat. Yes, I remember, he did double blind testing with steamed duck coated in duck fat after cooking versus traditional confit of duck. The thing is, when I did mine, I didnt just have fat, but quite a lot of other flavourings, which I wanted to be more mobile. But perhaps you are right, and even in this case, no fat is necessary.

Yeh I got the impression that it wasn't very good quality... what a waste of about $60. I'm tempted to get one of these, maybe with their calibration certificate too: http://www.burntechshop.com/easyview-type-dual-input-thermometer-with-dual-readings-p-204.html?osCsid=8510db0eb482f5f4a7e60a62d0088025 I have an Extech multimeter which includes a temperature probe. (A Minitech 26) It is well made and a good value as a multimeter. I would not use the Extech probe for liquid or for food. The probe I have appears to be the same bead probe included with the EA10 you linked. These bead probes are intended to measure air temperature not liquid temperature (or even contact temperature). The probe is not sealed to liquid and can not be cleaned. It is not a sealed probe like the Thermoworks probes (http://www.thermoworks.com/products/probe/index.html You could use a sealed type K probe (like the Thermoworks) with the Extech meter or just use a Thermoworks meter and probe. Looking at the Extech web site I see they have optional penetration and immersion probes too. http://www.extech.com/instruments/categories.asp?catid=68 Ed Yeh I wouldn't use the probe that came with it, I have already bookmarked another probe that was linked to earlier in this thread, which was a thin needle probe, which I would use to penetrate the bag (with foam tape), and another to measure liquid temperature. But thanks for the link

I put around 1.5-2 tbsps of duck fat in the bag with each thigh, and I actually didn't think it was enough...

traditional rub? Please define for the benefit of us neophytes. Thansk! Their is a confit thread on eGullet, or you could just google Confit rub... normally consisting of a lot of salt, and then other flavourings. I can't remember what exactly I used last time, but I think a combination of orange, lemon, clove, star anise, bay leaf, garlic, salt, pepper, thyme, rosemary, possibly some sugar? etc. The first post on the Confit thread is really good, I basically used that recipe. I did 80C for 12 hours. The texture was identical to the 100s of confit I have eaten in my life, except I made it myself I then poured the fat into a jar for later use

Yeh I got the impression that it wasn't very good quality... what a waste of about $60. I'm tempted to get one of these, maybe with their calibration certificate too: http://www.burntechshop.com/easyview-type-dual-input-thermometer-with-dual-readings-p-204.html?osCsid=8510db0eb482f5f4a7e60a62d0088025 But right now the precise temperature is not really that much of a concern, as I will most often cook for less than 4 hours in the danger zone, and most often will cook at temperatures 55C+ and calculate my times based on pasteurisation, with plenty of margin for error. I'm going to get a fever thermometer first, just to cross check my PID laboratory water bath

I would really like to try short ribs. I do not think they are popular here at all in the UK, but I had some when I was skiing in Breckenridge a couple of months ago, and they were f**king delicious! I would really love to try them. Perhaps when I can find a good butchers close-by, I will give them a try! I may also try sous-videing a rib-eye steak to see how it compares

Hey guys, I really appreciate all the feedback! Thanks for your suggestions! This is a laboratory PID controlled waterbath, so it has the most accurate thermometer that I own. I will, however, go to the health store tomorrow to get some fever thermometers to double check. These are the specifications of the waterbath: Tank Volume, liters 9.5 Useful Volume, liters 7 Temperature Range Ambient Temperature +5ºC / 99.9ºC Temperature Sensor Fe-Const Control System Programmable PID Microprocessor Temperature Set and Display Sensitivity 0.1 ºC Temperature Uniformity <40ºC ±0.2ºC Temperature Stability ±0.1ºC Timer 99.9 hours + Hold position Delayed Start Timer 1 min. to 99.9 hours Internal Material 304 Stainless Steel External Material Epoxy-Polyester Powder Coated Steel Power Supply 230V, 50/60 Hz Power Consumption 800 W Internal Dimensions (WxDXH) mm 240x300x150 This is from the manual: "The Tank of the bath is made of seamless corrosion resistant stainless steel for a longer life time and easy cleaning. By means of the smooth surfaces of the tank, the risk of contamination is minimised. The sheet heaters are placed on 3 sides outside of the tank, the use of a PID control system and triple insulation consisting of glasswool, an aluminum layer layer and an air gap, gives this water bath an excellent temperature uniformity and stability." The other factor could be that despite having 3 sides heated, extremely well insulated, and PID controlled - there isn't forced circulation. Furthermore, the tank size is just over 7 litres, which is perhaps not big enough? Marinading for days - I was inspired by PedroG's recipe for sous vide beef stroganoff using beef brisket. In terms of cooking below 55C, in this thread it has been noted that food poison-causing bacteria can not grow above 49C, and even at that temperature was due to the "pheonix phenomenom" which could only occur in a laboratory - according to Douglas Baldwin. Of course - I should check the accuracy of my waterbath before cooking at such a dangerous boundary for a prolonged period of time. The brisket was the best quality I could get my hands on. It was from the supermarket, but Tesco Finest Aberdeen Angus from their meat butcher counter. I am a university student, and the town where I live doesn't have any butchers since it is mainly catering for students who cannot cook! There is however a Waitrose which might be higher quality, otherwise I will have to Google any butchers close enough that I could walk to. I was thinking to cook the brisket at 52C to still give myself some margin of error (after checking the accuracy). But I'm unlikely to eat brisket anytime soon again, since my girlfriend wasn't particularly impressed and it is a bit annoying to have the waterbath occupied for 2 days.

I also cooked some pork ribs at 72C for 20 hours! Bit of a random temperature/time combination... but I looked a few different sous vide recipes, and made a compromise based on my time constraints! I have to say, they were soooo awesome!!!! So soft! Really delicious! And the ribs only cost about £2! I bagged them with a budweiser honey bbq marinade, some smoked chilli, salt and pepper, and some liquid smoke Don't ask me about the presentation... my girlfriend wanted to play on the mandoline slicer with some carrots.... I also reduced the juices from the bag and poured it over the ribs! They were awesome. Next time I would use more marinade... and reduce it to a sticky glaze and pour that over!!!

I haven't since my only other thermomter is one of the Maverick wireless dual probe types, and since I'm using a laboratory PID controlled water bath with 0.1C resolution, I presume the waterbath will be more accurate than the commercial thermometer. Also, I'm a big fan of not-pink-but-red steak! haha, I dunnoo, I just like it seared on the outside and nice and purple and rare in the middle. So it could be my on personal preference. Actually the meat was pink, just not pink enough for me!

I marinaded aberdeen angus beef brisket for 2 days with a combination of smoked chilli, smoked salt and pepper, liquid smoke, some butter, and some paprika. I then cooked it at 55C for 50 hours (was aiming for 48 hours, but got a little delayed). I have to say I was disappointed. Of course I have had brisket in many other forms and definitely the sous vide was extremely different. The meat was very tender indeed, it was like it had transformed into a totally different cut of beef. However, even though it was juicy, I found the mouth feel to be very dry after the first few chews. I also prefer my beef to be more rare. This wasn't particularly pink... closer to medium than medium-rare. I trimmed off quite a bit of the fat, but next time I would not, as the fat had a lovely flavour, and provided more moisture to the meat, which felt too dry to me. I then served it with an adaption of Heston Blumenthal's Perfect Roast Potatoes, using goose fat instead of olive oil, and some smoked chilli, salt, and pepper blend. Also served with some sauteed carrots with salt, pepper, and honey. Close up of the beef: The liquid you can see is the juice from the bag reduced a little, strained, and then had some butter incorporated, then a couple of spoonfuls over the beef. Next time I would like to cook it a couple of degrees cooler since I prefer my beef more pink. Furthermore, since this was an Aberdeen Angus cow, perhaps it was more tender than most briskets anyway, so the 48 hours (50 in my case) was a bit too much, and resulted in the drier texture. I would be tempted to try around 36 hours or so next time

Thank you joesan! You are extremely helpful! I didnt realise that it adds to the complexity of the flavour due to the different durations of cooking, so thanks for the information! I guess in this case then, that it requires double the ingredients conventionally required for a certain amount of liquid? (BTW I read many of your posts on the Sous Vide thread and found them most helpful! )

Thanks guys! I also asked the same queston to Dave Arnold at Cooking Issues, and he seemed to think it was a good model too! It's on my birthday list for next month now! Also, when making stock, have any of you tried the "double stock" method? I saw it on Heston Blumenthal's In Search of Perfection when he made a Chinese duck consomme. It seems like you use half the ingredients with 1 amount of water, discard those ingredients after cooking, use the same water again with the second half of ingredients. However, what I would like to know is whether you are essentially doubling the normal amount of ingredients for that amount of water, halving the normal amount of water for such an amount of ingredients, or getting much better results from a standard amount of ingredients and water?? I'm sorry if I'm not very clear