Sous Vide: Recipes, Techniques & Equipment (Part 6)

[Paul Kierstead]

Well, I just tried some short ribs. Wow, those were ridiculously good. I've never had such short ribs; by far, the best beef thing to come out of the sous-vide yet. These will be repeated. 45h @ 56C, went in with a little S&P&garlic powder. Most fat trimmed on the way in. Seared in grill pan + torch afterwords; made sure some fat rendered and moistened everything. Reduced bag juice with some W sauce, poured over.

[Guy MovingOn]

Has anyone done duck confit? You basically just take the legs and cover in traditional rub for a day or so.. Then cover in duck fat and cook at 85 C? I have seen NathanM on the early threads say 80 at first then say 82.2 C

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

Edited March 24, 2010 by Guy MovingOn (log)

[Guy MovingOn]

I have done duck confit for around 12 hours at 82 degrees. It worked well.

The fat in the duck rendered out very well so I didn't both putting extra fat in.

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...

[e_monster]

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.

[Edward Dekker]

The Maverick is not very good quality. I have one and mine is always 4 to 6 degrees off with the offset being random in that range. I called the company and they did not consider that degree of error to constitute a defect -- and refused to replace it or exchange the probe.

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

[e_monster]

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.

....

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.

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.

As far as something being a laboratory bath -- they still need to be checked and calibrated regularly.

As for food safety, I believe that you are not quite right in concluding that 52C should be safe. It is my understanding that most of these pathogens don't multiply over 49C but that is different from saying that they DIE at 49C. Cooking at 49C may keep the e coli from multiplying but it won't kill the e coli that is there. And some strains of c perfringens, if I read the material correctly aren't killed until the temperature is close to 54.4C.

I can't see anywhere that considers it safe to cook meat for longer than 4 hours at a temperature less than 54.4C -- and nowhere that suggests that meat can be pasteurized at a temperature less than that. Keep in mind that if the microoranisms aren't killed that you have been incubating them and they have been multiplying as the meat approaches 49C.

Given the penalty for being wrong, I think you would be wise to stick to 55C and above. The strains of e coli that have emerged in the last 20 years are nasty enough that you really really don't want to risk it. The difference in 'pinkness' between 54C and 55C is subtle at best.

Doug, Nathan? What do you think about cooking or long periods of time at temps below 54.4C?

[Guy MovingOn]

The Maverick is not very good quality. I have one and mine is always 4 to 6 degrees off with the offset being random in that range. I called the company and they did not consider that degree of error to constitute a defect -- and refused to replace it or exchange the probe.

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

[Guy MovingOn]

I have done duck confit for around 12 hours at 82 degrees. It worked well.

The fat in the duck rendered out very well so I didn't both putting extra fat in.

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.

[Guy MovingOn]

As far as something being a laboratory bath -- they still need to be checked and calibrated regularly.

As for food safety, I believe that you are not quite right in concluding that 52C should be safe. It is my understanding that most of these pathogens don't multiply over 49C but that is different from saying that they DIE at 49C. Cooking at 49C may keep the e coli from multiplying but it won't kill the e coli that is there. And some strains of c perfringens, if I read the material correctly aren't killed until the temperature is close to 54.4C.

I can't see anywhere that considers it safe to cook meat for longer than 4 hours at a temperature less than 54.4C -- and nowhere that suggests that meat can be pasteurized at a temperature less than that. Keep in mind that if the microoranisms aren't killed that you have been incubating them and they have been multiplying as the meat approaches 49C.

Given the penalty for being wrong, I think you would be wise to stick to 55C and above. The strains of e coli that have emerged in the last 20 years are nasty enough that you really really don't want to risk it. The difference in 'pinkness' between 54C and 55C is subtle at best.

Doug, Nathan? What do you think about cooking or long periods of time at temps below 54.4C?

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!

Edited March 24, 2010 by Guy MovingOn (log)

[Guy MovingOn]

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!

[e_monster]

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.

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.

[Guy MovingOn]

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.

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...

[Guy MovingOn]

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...

[Paul Kierstead]

Well, if you want to graph it super accurately, those would be fine. But what I'd look for right off the bat is just a general temperature offset, which is not uncommon. Then look for linearity problems by multiple samples. I would be surprised if there were strong linearity problems.

[slkinsey]

I had a nice success attempting to recreate the braised lamb sandwich at Landmarc. I browned lamb shoulder under the broiler, then bagged it with fresh thyme and rosemary and a mixture of softened onions and garlic, tomato paste and veal demiglace. Cooked at 63.5C for 36 hours and it was perfectly tender and shreddable, without a hint of dryness that normally comes from long braising to "well done." As I shredded it, I was able to separate out most of the fat, which was not needed to provide moistness as would ordinarily be the case with a braise due to the use of SV. Brilliant on ciabatta with mayonnaise and pickles, as they serve it at Landmarc, but also does very well with pasta.

[e_monster]

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...

I agree with Paul. First just set the PID to 38C and a few minutes after the temperature has stabilized, see what the fever thermometer says. Right now, you are just checking to see how closely the temps match. The most likely problem is an offset rather than a non-linear response.

[PedroG]

Compare at 38°C may do, it tells you the offset.

If you want to check if the slopes of the two thermometers are parallel, checking 32,34,36,38,40,42,42.9 will do and you can use my Excel-sheet for evaluation: http://home.ggaweb.ch/pgruber/thermometer_calibration_basal_working.xls (PID-controller-SET was in °F, because I had the SVM1500A only at that time, no decimals display, that's why I used °F for better resolution; you may enter PID-controller-SET in °C as well).

Linearity is another story, you can see an extreme non-linearity in http://sousvide.wikia.com/wiki/Thermometer_calibration (testo kitchen thermometer).

[nickrey]

... 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.

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.

[Guy MovingOn]

Well, if you want to graph it super accurately, those would be fine. But what I'd look for right off the bat is just a general temperature offset, which is not uncommon. Then look for linearity problems by multiple samples. I would be surprised if there were strong linearity problems.

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.

[Guy MovingOn]

... 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.

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

Edited March 25, 2010 by Guy MovingOn (log)

[PedroG]

Well, if you want to graph it super accurately, those would be fine. But what I'd look for right off the bat is just a general temperature offset, which is not uncommon. Then look for linearity problems by multiple samples. I would be surprised if there were strong linearity problems.

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.

Sure forced circulation does make a difference, see . My stockpot is 9L nominally, I use 7-8L water and an indoor fountain pump, and I never noticed a problem with meat cuts up to 700g or up to 3 bags, hanging vertical on a skewer (see ). If your bag is not in a vertical position, it might impede convection. As your bath is a bit shallow (post #3304) you might at least bring your bag to an oblique position by placing some weight in the bottom of the bag, see post #3384.

[Guy MovingOn]

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

[Guy MovingOn]

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.

Edited March 25, 2010 by Guy MovingOn (log)

[Guy MovingOn]

Sure forced circulation does make a difference, see . My stockpot is 9L nominally, I use 7-8L water and an indoor fountain pump, and I never noticed a problem with meat cuts up to 700g or up to 3 bags, hanging vertical on a skewer (see ). If your bag is not in a vertical position, it might impede convection. As your bath is a bit shallow (post #3304) you might at least bring your bag to an oblique position by placing some weight in the bottom of the bag, see post #3384.

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??

Edited March 25, 2010 by Guy MovingOn (log)

[e_monster]

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.