Sous Vide: Recipes, Techniques & Equipment (Part 2)

[pounce]

Doc, Thanks for the swamp cooler pump reference. Looks like a good solution for a dedicated bath that has some room. The concept is the same as my lab unit. Do you think you can add a rheostat on a motor like this? Even the small ones say something like 2500 To 5500 CFM. Wow.

Aquarium pumps and circulators are low voltage. Nobody would use them if they were 120 AC. Ornamental fish are expesive

[DocDougherty]

Do you think you can add a rheostat on a motor like this? Even the small ones say something like 2500 To 5500 CFM. Wow.

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Pounce,

The 2500-5500 cfm would indeed be a lot of water (19,000 - 41,000 gal per minute), but it is actually the air flow rating through the swamp cooler rather than the volume of water that goes through the pump. The smallest size is all you are likely to need as it still will move a lot of water. Here is a link to a typical pump (Swamp Cooler Pump). Since they are designed for only about 36" of head, even a small flow restriction will drop the volume substantially. A section of small diameter tubing would be enough if you can find compatible fittings to step down the diameter - then you can trim it back until you get enough flow; or you could put an end cap on and drill it out to a size that works.

As for a rheostat to control the speed of the pump? I don't know. It depends on how the motor is wound. I would just use a flow restriction and not worry about an electronic solution. Besides the electronic control engineers learned most of they know from their mechanically inclined forefathers - and there is usually a cheap mechanical analog if you can just figure out what you need and find the right parts at the hardware store.

My Lauda (E100 I think) has three speeds on the circulation pump, but I rarely use the highest speed in the 6" steam pan that I use for a sous vide tank.

Doc

Edited October 20, 2007 by DocDougherty (log)

[adey73]

For me this is the post topic ever, I have learnt a great deal from Nathanm and others.

But has anyone experimented with cooking times with green veg?

Vac sealed asparagus and sous vide cooked, brined before hand?

Confit of tomato cooked in oil and garlic?

Or Spinach that doesn't loose it's vibrant green colour?

Edited October 20, 2007 by adey73 (log)

[nathanm]

I'm glad you like the thread - sous vide is an interesting and powerful cooking techinque.

Vegetables tend to get less focus than proteins in sous vide generally speaking.

The main reason for this is that protein products have very delicate transition temperatures - which give you a narrow range between underdone and overdone. That is where sous vide has a larges advantage over conventional cooking techniques.

In many cases vegetable cooking is about softening the cell walls of plants. This tends to require relatively higher heat than protein products - you need to get fairly close to the boiling point of water, say 180F/82C to 200F/93C. In some cases you are better off just steaming the vegetables.

The difference in temperature requirements means that it can be difficult to cook meat and vegetables together. If you put veges in the bag with meat you cook at 130F/55C - even for days - they will stay crisp. You need to pre-cook the vegetables to the desired state prior to putting in the bag.

The best cases for sous vide vegetables are where you need delicate control of temperature. Sweet corn is a great example - 150F/65C for 10 minutes is wonderful. Fresh garden peas are another good example.

A second area where sous vide is very useful is for items like endive or artichokes which tend to turn brown when cut. Cooking in a vacuum helps a lot in these cases.

So, by all means experiment with vegetables sous vide!

[adey73]

I just did Nathan.

I removed the skin of some tomatoes in boiling water and put them in vac bag with extra virgin, garlic and lemon thyme and S&P. Sat them next to larder trimmed striploin for the final 2hrs of the 24hr process you recommend. Sweet mama! they had soaked up all those flavours, so vertically sliced the top of the tom and placed a crispy piece of bacon. Result. 24hr Chateaubriand, bearnaise sauce with thrice cooked chips (or fries as you call 'em). Heaven.

[Peter the eater]

SV is a lot of fun to experiment with, over 1000 posts here bear that out.

Question: Whats on your top ten list of foods that benefit from this technique?

I had SV scallops the other day and quite frankly, I'd rather have them raw or warmed up a bit with butter or with a bit of acid (citric not lysergic). But lamb shanks is another story. What do you industry experts and home experimenters (like me) think?

[jmolinari]

short ribs, pork belly, chicken breast

[syoung68]

I am stupid! First there were the two years of "I am not going to boil-in-a-bag cook". Then came the months of "maybe there is some validity to this". Lately it has been, "When I get a food saver..." Finally, Saturday night, I broke down and just put some food in a double lock ziplock and plopped it into some water and waited.

I repeat, I am stupid.

Before I let you brilliant people know what I cooked, let me say WOW! I should have done this 3 years ago. There is not a lot of sous vide going on in New Orleans, at least it is not advertised on menus, so I was not sure I had ever had properly cooked sous vide. Now, in hind sight, I can remember one meal in particular that I had marveled at the texture of the veal - it HAD to be cooked this way.

So here it goes, in the spirit of an Alinea description...

PORK TENDERLOIN: Apple, Onion, Sweet Potato

First I sauteed apples and onion together, then pureed, let cool, and put into a bag. Added the pork and it all went in the fridge while I figured out my water bath. I used a stockpot and a digital thermometer and had to adjust the burner more frequently than I would have liked, but I figured out how to maintain 140F +/- 2 degrees. The pork went in for 3 hours.

In the meantime I wilted spring onion and roasted some diced sweet potato.

When the pork came out, it was not pretty but I expected the color so I was not put off. After a brief rest, I quickly seared it in the residual oil that I had wilted the onions in. Upon slicing, the meat was beautiful. When I took my first bite - the chef's taste - I nearly wet myself. Pork. Glorious pork. This is how a tenderloin should taste.

I plated with with a cane syrup butter, the onions and the potato, and dressed the plate with balsamic reduction and a green salt I made with some of the onion tops.

Needless to say, my guests were floored. One commented that it tasted like bacon with out fat.

So I am turned. Like a Vampire after his first kill.

I may never grill anything again. Ok, that is a lie, but a food saver will be ordered soon, and I am keeping my eye out for a good deal on a circulator. The only real question is "What to do next?"

[DocDougherty]

SV is a lot of fun to experiment with, over 1000 posts here bear that out.

Question: Whats on your top ten list of foods that benefit from this technique?

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In no particular order:

Chicken breasts

Salmon

Black cod

Scallops

Lobster tails

Tri-tip

Turkey thighs

Lamb shanks

Turkey breast tenderloins

Pork tenderloins

[Digijam]

Vegetables tend to get less focus than proteins in sous vide generally speaking. 

The main reason for this is that protein products have very delicate transition temperatures - which give you a narrow range between underdone and overdone.  That is where sous vide has a larges advantage over conventional cooking techniques.

In many cases vegetable cooking is about softening the cell walls of plants.  This tends to require relatively higher heat than protein products - you need to get fairly close to the boiling point of water, say 180F/82C to 200F/93C.   In some cases you are better off just steaming the vegetables.

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What he said . Though just to add that if you have access to a vacuum chamber rather than a vacuum sealer type machine, then some things won't even require cooking. The pressure, in combination with some freezing, will crush the cell walls of veg like asparagus - hit 'em with too much compression and they can even taste overcooked.

Check out eG regulars like Sean Brock, Alex and Aki at Ideasinfood, and Shola at Studiokitchen for compressed fruit and veg cleverness.

Edited October 23, 2007 by Digijam (log)

[nathanm]

Actually, the pressure occurs when you use a vaccum sealer, not a vacuum chamber.

In a vacuum there is no pressure! When the food is sealed in a bag, ideally in a chamber style machine, there is no pressure on it in the chamber. But once you put into the air, it gets 14.7 lbs per square inch pressure from the outside air. That is what crushes the vegetables.

[syoung68]

Can this be accomplished with a consumer grade machine? I am going to buy a Foodsaver or the like next month.

[alwang]

I find the compression effect pretty marginal with consumer FoodSaver-type machines. You're facing two issues: First, the Foodsavers don't pull a powerful enough vacuum unless you're working with fruits and vegetables that are already fairly soft. Second, if you're working with softer veggies, or if you're attempting to infuse the vegetables with some flavoring liquid, the FoodSaver will tend to suck out the juices/liquids.

I've had interesting results with a few experiments (figs for example), but most were pretty meh.

[syoung68]

is this true of any external motor vacuum sealer? I am really just talking about compression. you could always use the hard sided canisters for infusion.

Edited October 23, 2007 by syoung68 (log)

[blixa]

is this true of any external motor vacuum sealer? I am really just talking about compression. you could always use the hard sided canisters for infusion.

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Using the hard-sided canisters for infusing is something I'm just starting to experiment with, and the results can be great. Just recently I infused peeled tomatoes with a mixture of watermelon juice, tomato water and a splash of yuzu juice. After letting it sit for half an hour or so, I removed the tomato and warmed it a bit. Boy was that an explosion of flavor!

[DocDougherty]

the Foodsavers don't pull a powerful enough vacuum

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Perhaps I don't understand the basis for comparing the vacuum performance of various machines. A chamber type machine does not have to suck the air out through the very fine channels left by the cross-hatching on the inner surface of the bag (in fact a chamber machine can use the less expensive smooth bags), so when it gets to 1 mm of Hg, everything in the bag is at that pressure and the increase in pressure after sealing is due only to the ratio of free volume in the bag before and after returning it to atmospheric pressure. A Food-Saver on the other hand must generate sufficient vacuum to transport the residual air in the collapsed bag around the food and out through the vacuum port, and even with 1 mm of Hg at the pump, the inside of the collapsed bag has a somewhat higher pressure since it can never totally equalize due to the low differential pressure. But the bag is collapsed already and the pressure doesn't increase after the seal is made, at least until the bag goes in the water bath and the residual air begins to expand. Can somebody explain the relative performance of these two types of machines in a quantitative way?

Doc

[alwang]

What I meant was that Foodsavers don't pull enough of a vacuum to do the sort of heatless compression "cooking" of vegetables that Digijam was referring to. Foodsavers are absolutely fine for sealing bags for water bath cooking, and are in fact what I use.

[nathanm]

the Foodsavers don't pull a powerful enough vacuum

←

Perhaps I don't understand the basis for comparing the vacuum performance of various machines. A chamber type machine does not have to suck the air out through the very fine channels left by the cross-hatching on the inner surface of the bag (in fact a chamber machine can use the less expensive smooth bags), so when it gets to 1 mm of Hg, everything in the bag is at that pressure and the increase in pressure after sealing is due only to the ratio of free volume in the bag before and after returning it to atmospheric pressure. A Food-Saver on the other hand must generate sufficient vacuum to transport the residual air in the collapsed bag around the food and out through the vacuum port, and even with 1 mm of Hg at the pump, the inside of the collapsed bag has a somewhat higher pressure since it can never totally equalize due to the low differential pressure. But the bag is collapsed already and the pressure doesn't increase after the seal is made, at least until the bag goes in the water bath and the residual air begins to expand. Can somebody explain the relative performance of these two types of machines in a quantitative way?

Doc

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You are both right. An edge suction machine, like Foodsaver, must suck the air out from one side, and it is harder to do a good job of that.

A quantitative assessment would be be the amount of residual air left in the bag. I don't have a good measure of this - it is difficult to measure directly. Generally you get better results from a chamber style machine, for the reasons listed above - an edge sealing machine must try to suck the air out from the edge. The cross-hatch channels help with this, but not perfectly.

Note however that there will not be that much difference in the pressure. Atmospheric pressure is 14.7 lbs per square inch. A perfect vacuum in the chamber prior to sealing would result in that much pressure on the outside. No vacuum is perfect, but good chamber machines are probably 99% vacuum. However, a 90% vacuum would still be 13.3, which is almost the same amount of pressure.

Another way to say this is that the amount of pressure depends on the atmosphere, not the machine. Even a rough vacuum gets you a lot of the pressure.

[syoung68]

I was thinking of the compressed fruits and vegetable that people are doing. e.g. watermelon or eggplant. Does a Foodsaver compress it enough to change the texture of the fruit? Not necessarily the cooked spinach that was done at StarChefs but dense watermelon would be cool.

I guess, I am really asking if one Foodsaver or similar product does a BETTER job than others. Short of dropping $1K+ on a chamber machine.

Edited October 24, 2007 by syoung68 (log)

[Ruth]

I have the Professional III Foodsaver which I believe has the strongest motor. It also has a feature which permits you to extend the vacuuming process beyond what the sensor on the machine considers necessary. Watermelon is pretty much out of season now but if I see one I'll try to compress a piece and let you know what happens.

[Digijam]

In a vacuum there is no pressure!  When the food is sealed in a bag, ideally in a chamber style machine, there is no pressure on it in the chamber.  But once you put into the air, it gets 14.7 lbs per square inch pressure from the outside air. That is what crushes the vegetables.

←

Indeed - should have clarified that I was referring to the forces placed on the food after removing it from the chamber.

Note however that there will not be that much difference in the pressure.  Atmospheric pressure is 14.7 lbs per square inch.  A perfect vacuum in the chamber prior to sealing would result in that much pressure on the outside.  No vacuum is perfect, but good chamber machines are probably 99% vacuum.  However, a 90% vacuum would still be 13.3, which is almost the same amount of pressure.

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This is clearly going to be one hell of an in-depth book. Just out of curiosity, can we expect much about how much sous vide really affects penetration of marinades? Hoping to read more about your experiments using sous vide in conjunction with the Jaccard, too, both in the way it alters retention of natural juices when cooking, and whether it makes any difference when infusing.

[qrn]

I was thinking of the compressed fruits and vegetable that people are doing. e.g. watermelon or eggplant. Does a Foodsaver compress it enough to change the texture of the fruit? Not necessarily the cooked spinach that was done at StarChefs but dense watermelon would be cool.

I guess, I am really asking if one Foodsaver or similar product does a BETTER job than others. Short of dropping $1K+ on a chamber machine.

←

I have the Professional III Foodsaver which I believe has the strongest motor. It also has a feature which permits you to extend the vacuuming process beyond what the sensor on the machine considers necessary. Watermelon is pretty much out of season now but if I see one I'll try to compress a piece and let you know what happens.

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How can you vac bag a piece of watermelon with a foodsaver???If there is any liquid near the seal it does not seal...(at least mine will not)

I was looking at some of the non f/s types with the smooth bags and wonder if they deal with moisture better?? Wonder if anyone is using them??

Bud

[alwang]

How can you vac bag a piece of watermelon with a foodsaver???If there is any liquid near the seal it does not seal...(at least mine will not)

I was looking at some of the non f/s  types with the smooth bags and wonder if they deal with moisture better?? Wonder if anyone is using them??

Bud

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This is what I was trying to get at earlier: with soft foods that have a lot of juice, the Foodsaver-type machines draw out the liquids, and you've forced to seal prematurely, resulting in less pressure. I've tried this specifically with watermelon, and I did not find the result worth repeating. The only workable scenario is with soft foods which are not so juicy, such as figs.

[slkinsey]

How can you vac bag a piece of watermelon with a foodsaver???If there is any liquid near the seal it does not seal...(at least mine will not)

Just make the bag extra-long, put the watermelon in the bottom of the bag and put a pleated paper towel around 2/3 of the way up.

[Chris Hennes]

Has anyone seen these: Reynolds Handi-Vac? My wife has a coupon for a free one and I was wondering if it might be useful for Sous Vide on the cheap. Of course, they intend it for freezer use, not higher-temp applications, but since the temps involved are still relatively low, I wonder if it would work OK. Probably a bit better than just "boil in a bag" but not as well as a real vacuum sealing machine? The price is right, anyway .