PedroG

Vegetables and fruits have air inclusions which will expand with rising temperature and make the bags float. Use marbles in the bag (at the bottom) and suspend the bags on a skewer to assure vertical position. In my experience, with meat suspending is sufficient to avoid floating, I use marbles plus suspension with very fatty food like bacon or butcher's chops.

See upthread, it is possible but a bit tricky using an edge sealer.

At 53oC pathogens won't multiply, but (thermophilic) spoilage microbes may thrive well above 55oC. See FOOD AND INDUSTRIAL MICROBIOLOGY. I experienced this once with factory-marinated and vacuum-sealed spare ribs.

Pedro, the video in the post you linked looks like it is no longer threre. Can you repost the video? The video still works, at least with Firefox and IE9. Here is a direct link: .

Very elegant method, rotuts! Thanks for the idea. So far, instead of using a funnel, I folded the sealing region of the bag outside and downward to keep it clean, as Nathan described in MC 2.219, see my post on sealing liquids using an edge sealer. Needs no additional gadgets. BTW thawing a flattened bag of frozen leftovers like the one shown in the post I mentioned just takes a minute or two in warm water in the kitchen sink.

Very interesting observation! Regarding floating bags with 85% vacuum, see "The vacuum level dilemma with chamber sealers for sous vide cooking"; did you try my suggestion?

Thanks, Douglas, for clarifying the 4h/6h question again. The answer to "how big a roast i could sous vide" is given in table 2.2 of Douglas' practical guide: Without pasteurization (4h-rule) the limits are: slab 55mm, cylinder 75mm, sphere 90mm. With longtime-cooking (24-72h) there is pasteurization automatically included, so the limits (6h-rule) are: slab 65mm, cylinder 95mm, sphere 115mm. When pasteurizing in short time cooking, Douglas' table 5.1 (meat) and table 4.1 (poultry) set the thickness limit at 70mm. You see a synopsis of these limits in the thickness ruler. BTW the 4h/6h-rule has already been addressed in the old SV topic in May 2010. Wouldn't this only apply to rolled structures, or something that otherwise had the potential to be contaminated internally? Would whole muscles be exempted from this? Yes, provided your meat has a regular surface without any deep clefts your meat has not been jaccarded no one from slaughter to butcher to your kitchen has ever punctured your meat with a fork or the like the animal was not infected with any pathogen without showing signs of disease In this case, a short dunk in hot water (e.g. 80oC / 1 sec, see the wikiGullet article "Importance of temperature control on pasteurizing times") would pasteurize (the surface of) your meat.

Thanks, Douglas, for clarifying the 4h/6h question again. The answer to "how big a roast i could sous vide" is given in table 2.2 of Douglas' practical guide: Without pasteurization (4h-rule) the limits are: slab 55mm, cylinder 75mm, sphere 90mm. With longtime-cooking (24-72h) there is pasteurization automatically included, so the limits (6h-rule) are: slab 65mm, cylinder 95mm, sphere 115mm. When pasteurizing in short time cooking, Douglas' table 5.1 (meat) and table 4.1 (poultry) set the thickness limit at 70mm. You see a synopsis of these limits in the thickness ruler. BTW the 4h/6h-rule has already been addressed in the old SV topic in May 2010.

Did you check out the VAC-STAR 'MiniVAC' at EUR 1'126.67?

I would not recommend this, and I would definitely not put the eggs in bags filled with water. In general, you want the water to circulate freely around your food as it cooks. If there is water in a bag with the food then that water is not circulating around the bath back to the heating element. I would not worry too much, though. I cook eggs regularly and breakage has never been a problem. Vengroff, as one Chief Scientist/Amateur Cook to another, I have to strongly disagree with you. In my experience, as well a PedroG's, egg cracking is a quite common problem, and if you are using any kind of a circulator, a real PITA to clean up afterwards. I certainly don't want to ruin an expensive circulator for a minor inconvenience! If the bag containing the eggs is filled with just enough water to cover the eggs in a single layer, and importantly, the water that you use is already up to temperature (having been extracted from the bath), any temperature differential is likely to be minimal. Your could of course test this by sealing a thermocouple inside the bag, using the Archimedes principle, and I confess that I haven't done so, but if it was more than 0.5 degree F I would be quite surprised -- astonished, in fact. Bob I totally agree with Bob: Finagle's corollary to Murphy's Law says: Anything that can go wrong, will -- at the worst possible moment. (i.e. in a SV bath most difficult to clean). Cleaning a SVS after breaking an egg may not be a very big deal, but in an FMM or IC you may need to use a professional grill-cleaning-solution containing sodium hydroxide to clean the mess. I did my last SV eggs in a skewer-suspended ziploc bag partly filled with hot water from the SV bath to displace the air, and the outcome was the same as with naked eggs in the bath.

There might be a few "dumb" portable induction hubs out there with mechanical controls, like the Viking - Portable Induction Cooker or the Tundra Manual Control Countertop Induction . If you really encounter a dumb induction hob, I guess with a SVM it would make a very responsive (low thermal inertia) system similar to an immersion heater like FMM. Did anyone try one of these with a SVM?

See Harald McGee, On Food and Cooking, p.150: Juices are squeezed out of the cut ends of muscle fibers, so a slab cut against the grain is prone to lose more juice than a thicker cut, also in SV cooking. Liquid loss in short time cooking is much less than in LTLT cooking. In a 48h/55oC brisket I measured liquid loss of up to 20%, with dry aged brisket it was about 10%.

250mBar is 75% vacuum, an edge sealer would do, place your foam in an external rigid vacuum container and pull 75% vacuum with an edge sealer or chamber vac.

My FMM is in the water 365d/y without any problem.

infernoo, thank you for reporting your interesting experiment. Enzymatic tenderization has been exhaustively discussed in excellent posts by nathanm and Douglas Baldwin. As e-monster says, in this experiment it must be thermal conversion of collagen to gelatin, and it makes sense that you get a tenderization with 56oC/72h similar to conventional cooking 80oC/12h. The enzyme collagenase is reported to denature at 60oC; this means, above 60oC it must denature, but at temperatures below 60o it may denature but at a slower rate. So maybe our 55oC/24-72h cooking converts collagen to gelatin enzymatically (and thermally) during the first 6 or so hours, but collagenase activity decreases with time, and continued cooking will convert collagen to gelatin mainly thermally. When cooking at higher temperatures, undenatured collagen reaches shrinking temperature before being converted to gelatin, squeezing juices out of the muscle cells, resulting in dry yet falling-apart-tender meat.

Looks nice, no health concern, but with a bimetallic situation you might have corrosion problems, see upthread post #495 to post #513. Fortunately, if corrosion should happen, it would damage the aluminum sheet rather than the stainless steel circulator.

Hi Seth, welcome to eGullet and the sous vide community. See my earlier comment on the new version of Douglas Baldwin's Practical Guide. Many other tables or apps may be based on the older version of Douglas' tables which did not yet take into account E.coli for pasteurization times.

That sound very reasonable. Maybe it would be sufficient to buy 1 pack and do the experiment with two one-rib-cuts? Looking forward to your results.

At 190oF (88oC) all enzymes have been denatured and inactivated, the meat dry and and the muscle proteins densely compacted. -> irrecoverable. So (for the sake of discussion) if I were to purchase a pre-cooked packet of beef/pork ribs that is vacuum packed in a "BBQ Sauce" that I KNOW are tough straight out of the packet (and definitely has already been cooked to well done temperatures), sous videing them for 48-72 hours at ~56c would not yield a more tender product? No. (Try it, then you will know and have something to report).

I'm really glad to see you and your 5-year old using metric measurements in these recipes. Even the UK has gone metric for some time now, as well as Canada, leaving only the US consumer to fumble around with demonstrably inaccurate volume-based teaspoons, tablespoons. and cups, as well as ounces, pounds, etc. The rest of the world is passing us by, and our antiquated measurement system is at least part of the problem. Wake up, people! It isn't all that hard. If a 5 year old can do it, why can't you! And cookbook authors, PLEASE get with the times! Bob Thank you, Bob! A kitchen scale is also good for measuring volumes. E.g. for cooking pasta, place the pot on the scale, tare, add 30g salt, tare, add 3000g water, and ready you are to cook 300g pasta, and you don't have to dry a measuring vessel.

A more simple first pilot would be to cook two identical cuts, one as you first proposed and the second for the same total time at 59C for the whole 15 hours. This would allow a fairly pure test of the second, higher temperature, cooking. I agree. Cooking times for the two stage method would have to be determined. MC 5.44 recommends 60oC/72h for short ribs. Braising recipes recommend up to 12h at 80oC. I guess in the two stage approach both times can be reduced, but how much? A combined approach could also be SV at 59-60oC, optionally chill and store, then sear and continue as a traditional braise. Note that heating very gently and gradually may prevent the myoglobin pigment from denaturing to hemichrome (McGee, On Food and Cooking, p.163-164), resulting in a well-done yet pink (and fork-tender and succulent) meat.

One issue would be the cooking times. Air is rather poor at transferring heat -- so cooking times will be radically longer if you are cooking in air rather than water. So, you would need tables for safe cooking times and the time to get the food to temperature since none of the existing tables would apply. You would need to be especially careful about the length of time that the food would spend in the danger zone. There are some Heston Blumenthal recipes that do low temperature cooking in that range in the air -- all of them involve sterilizing the outer surfaces before cooking. (Either by blasting with a blowtorch or dunking in boiling water). With an oven that goes that low and has such small temperature swings, you could probably do some pretty decent sous-vide with the bags and water in a dutch oven. Pedro used to use a set-up like that pretty successfully if I recall. I agree with e-monster, you can easily do sous vide in your oven with a water pot. If your oven is too small for an 8L pot, a smaller one may do (I started SV in an oven with a 2.5L pot); in my experience bags tend to float in a shallow pot where they cannot be positioned vertically, so you might weigh down the bags by including marbles or glass beads.

At 190oF (88oC) all enzymes have been denatured and inactivated, the meat dry and and the muscle proteins densely compacted. -> irrecoverable.

This discussion is continued in the main sous vide topic.

Continued from the topic Technological Cooking Is it everything it's supposed to be? Um, Pedro, could you say that in English? Seriously, an example with times and temps to try would be great! If I may. PedroG is saying that cooking could potentially be done in two separate stages. The first burst would be below 60C to ensure that everything except tough collagens and fibrous tissues are cooked as we have become accustomed to with sous vide such that they are tender and their juices are retained. He is then proposing a second cooking at a higher temperature to deal with the other more gristly bits. Presumably the earlier cooking will stop the more temperature sensitive pieces from shedding much of their juices as they would if you put them immediately into the higher temperature water bath. Look forward to hearing the results of your experiments on this PedroG. OK, an idea for starting experiments would be: Boneless short ribs, bag and place in cold water bath, set temperature to 59oC (ideally, the temperature rise from ambient to 59oC would be about 4 hours), after 12 hours set temperature to 75oC, 3 hours later sear and serve. To proceed more scientifically, cook four equal cuts at 59oC for 6 / 12 / 24 / 48 hours and compare tenderness of meat (disregarding parts with thick connective tissue). With the best choice of first stage of cooking, compare 1 / 2 / 3 / 4 hours of second stage cooking at 75oC comparing tenderness of connective tissue and juiciness.