1176 replies to this topic

[RDaneel]

Thank you, Pete J, for the creative idea. I like it...

[PedroG]

Hi Pete J,
that's a very smart solution, it avoids the interference between my bent skewer and the lid of any pot. But I suggest to try to force the bags into a vertical or at least oblique position for better (natural or forced) circulation, so you might pin the bag to the fiberglass rod with clothes-pins and eventually weighing the other end of the bag down.

[PeteJ]

Thanks for the suggestion, PedroG. If you'd like, I'll send you a set of fiberglass rods to use in your cooking. I'll need to know the diameter or width of your bath. To that, I'll add 1/4 inch and make four rods for your cooking. Please send me a private message here with your address.

Incidentally, I ordered a bag of marbles yesterday. I like your idea of suspending the bags vertically.

[dougal]

Unless you are using a circulating pump, you NEED to have the bags vertical.

If your heat transport is not powered, a horizontal bag will lead to much greater temperature differences within the bath - and the idea is to make the temperature as uniform as possible.
Convection currents are a rising and falling phenomenon, and a horizontal barrier prevents them doing their work as well as they could.


Regarding the glass marble/bead inspiration ...
DocDougherty http://forums.egulle...ost__p__1275139 mentioned it back in September '06
Someone else brought it up http://forums.egulle...ost__p__1731993 on 27 Feb 10
And then it was nicely documented by PedroG http://sousvide.wiki...s_from_floating on 15 March 10




With weighted 'sinky' bags, rather than suspending them from above, I find a 'toast rack' to be very cheap, simple and convenient to maintain alignment and some separation between vertical bags.
I have a couple of £1 (about US $1.50) chrome-wire toast racks (from Poundland, a UK retailer), which originally looked very much like this one http://www.kendermar...ast Rack_46.jpg
Removing every second 'divider' (with a bolt cutter!), gives me slots that are 1 and 3/4 inches (4 cm) wide, a nice size for 'portion' bags.
Simple, cheap and effective. A good combination!

[e_monster]

Unless you are using a circulating pump, you NEED to have the bags vertical.

In my experience, this is not quite true. If the bag is submerged and there is space on all sides and there is sufficient water to food ratio, the convection will result in circulation and the heat distribution will be quite even. The rising of the water from bottom to top will force water to be pulled down which causes general circulation. If the cooker is overloaded this might prevent adequate water flow.

I have tested this countless times in my large rice cooker and the temperature equalizes quite well. I have never found a temperature differential of more than 1 degree fahrenheit if the cooker isn't overloaded once the food has come close to temp. And even 1 degree F is unusual once the food is at temp.

As a result, I am only using circulation when I am pasteurizing near an important temperature boundary.

Best,
Edward

[RDaneel]

Does anyone have any thoughts on the Addelice Swid? I'm currently saving (and saving, and saving) for an immersion circulator, and both the Polyscience "Sous Vide Professional" and the Swid appear to be good options. Both have adequate power, are designed for home use, digital controls, PID autotuning, etc. The Swid is 449 Euros, which is significantly cheaper than the $799 for the Polyscience. I haven't yet heard anything bad about the Swid, except that, like the Polyscience, it isn't available yet (at least in 120V form). Addelice predicts 120V availability in "summer," I think.

Preordering Nathan's book took a quite large chunk out of my discretionary funds (I'm really banking on it to be a valuable book with an impact on my cooking for decades to come), but I'm hoping to pick up a circulator later this summer, so any impressions are welcome.

Thanks in advance...

Edited by RDaneel, 23 June 2010 - 03:07 PM.

[dougal]

... {using a submerged, horizontal bag}
I have tested this countless times in my large rice cooker and the temperature equalizes quite well. I have never found a temperature differential of more than 1 degree fahrenheit if the cooker isn't overloaded once the food has come close to temp. And even 1 degree F is unusual once the food is at temp. ...

Yes, its the 'getting to temperature' phase that will show the most dramatic difference.
And that is going to have the greatest impact if you are ever doing "non-equilibrium" (or short time) sv cooking.



I can load three bags into one of my vertical racks and all three will cook pretty much identically.

Turn that same stack sideways, and the one in the middle is going to take much much longer to get to temperature.

To put it a different way, a sv cooker without powered circulation, has a greater capacity for bags if the bags are mounted vertically. And that capacity difference (before the bath is "overloaded") is at its greatest when trying non-equilibrium or short-time sv cooking.


I don't see any actual advantage to horizontal bags - other than when the only water bath available is somewhat shallow. What insight am I missing?

[e_monster]

A couple of things.

There are times when you have items that just don't fit vertically even if it isn't a particularly shallow bath OR it might be a hassle to stack things vertically. It isn't that there is an advantage (other than convenience).

As I said, horizontally doesn't require forced circulation if you have sufficient space around and above (and under) the items. Your example is one where you don't have sufficient clearance on all sides for convection to work. I agree that if you are trying to fit a lot of stuff into the bath that vertical placement is best.

I am not suggesting that it is better to have things being horizontal just that it isn't necessarily worth the hassle to be able to get things vertical -- as in many cases it makes no difference.

[RogerC]

Putting milk into bags, or smaller containers would heat faster, but convection in the jug may be sufficient.

Thanks for the great info. I did this today with a half gallon jug and it only took about 15 minutes or so to come up to temperature. Worked very well. Thanks again.

[nathanm]

A few replies to recent posts.

Hanging vertically is in general better than horizontal, because the water in contact with the food is cooled, which makes it slightly denser, so it sinks vertically (beacuse gravity points down). This process is called natural convection.

An extreme version happens with your freezer. Hold you hand below the door while you open it (assuming it has a vertical door), and you will feel the cold air pour out. For a freezer this is bad - it means you lose lots of cold air every time you open it. Chest freezers don't have this issue.

Anyway, in an unstirred bath like Sous Vide Supreme, natural convection is important source of movement, and in general it is better if you place food so that natural convection will be encouraged.

With a stirred bath (i.e. one with a pump) this is less important. The pump produces forced convection which in general dominates the much weaker natural convection. Natural convection is weaker because the temperature difference is generally pretty small so the density differce is pretty small too.

Of course these are generalities that apply to packing a bunch of flat items (say, a half dozen steaks).

If you have a spherical object, "horizontal" and "vertical" have no meaning! That is pretty much true for cylinders also. If you are cooking a whole squab, or a chateaubriand or some other cylinderical food, it really isn't going to matter that much. Also, if you have a small object in a large bath, it won't matter much.

The goal in all cases is to get good water circulation. Jamming the bath very full is a bad idea no matter what orientation is used.

[nathanm]

Preordering Nathan's book took a quite large chunk out of my discretionary funds (I'm really banking on it to be a valuable book with an impact on my cooking for decades to come)

We've been working hard to make it a book that you'll feel good about - and I hope you think so once you see it!

[BenT]

This is aside from the current conversation regarding the verticality of the bag in the bath - (though Nathan's comment regarding natural convection was a very nice 'aha!').

Here's one for y'all - especially the bbq purists - and it is blasphemy to the brethren - I've started doing my pork shoulders Sous Vide. Normally, I would trim, tie, and rub the shoulder, wrap it tightly in Saran Wrap and let it sit for a couple days before smoking. Then Smoke for about 5 hours @ between 230 - 280, then finish in a dutch oven, rendering the remaining fat into the BBQ sauce.
Recently, I've started to put the rub on the shoulder, then vacuum seal the roast. a day before 'cuing, I put the roasts into a water bath @ 140F for 24 hours. pull the roasts out, let rest for a few, then smoke for 3-4 hours. Finishing again in the dutch oven, just because I like how the smoke gets imparted to the sauce.

I started doing this because I could not get my BBQ "done" by the time guests started to arrive. And it works great. I can get a really tender pulled pork thats melt in your mouth good. Not traditional, but I can still get a decent bark on it and a decent smoke ring, and I don't have to watch the fire nearly as much.

On the one hand, I feel guilty for cheating, on the other hand - it's just really tasty. My friend from Georgia even gives it his stamp of approval.

Nathan - I am really looking forward to seeing your book, and I am finding the cash to order a copy. I am glad its a book and not an epub. Books are a paramount technology.

Apologies if my BBQ/Sous Vide method is in any way offensive and/or sloppy cooking. It's just the way I roll...

[nickrey]

Apologies if my BBQ/Sous Vide method is in any way offensive and/or sloppy cooking. It's just the way I roll...

If you're on this thread, you're open to new ideas and new ways of approaching traditional cooking. I don't think you're going to get push back here.

Sounds great.

[e_monster]

I suggest also trying doing it in the other direction. Smoke for about 30 minutes at 180 or 190 and then bag the meat and cook it sous-vide. And then finish it off very briefly under the broiler to give it a little crunch. I find that smoking first for 15 minutes to 30 minutes provides great smoke flavor that penetrates very well -- much better than when done the traditional way (When I cook it traditionally, I usually do pork shoulders for 12 to 14 hours somewhere in the 190 to 200 range)

Just a thought.

--E

This is aside from the current conversation regarding the verticality of the bag in the bath - (though Nathan's comment regarding natural convection was a very nice 'aha!').

Here's one for y'all - especially the bbq purists - and it is blasphemy to the brethren - I've started doing my pork shoulders Sous Vide. Normally, I would trim, tie, and rub the shoulder, wrap it tightly in Saran Wrap and let it sit for a couple days before smoking. Then Smoke for about 5 hours @ between 230 - 280, then finish in a dutch oven, rendering the remaining fat into the BBQ sauce.
Recently, I've started to put the rub on the shoulder, then vacuum seal the roast. a day before 'cuing, I put the roasts into a water bath @ 140F for 24 hours. pull the roasts out, let rest for a few, then smoke for 3-4 hours. Finishing again in the dutch oven, just because I like how the smoke gets imparted to the sauce.

I started doing this because I could not get my BBQ "done" by the time guests started to arrive. And it works great. I can get a really tender pulled pork thats melt in your mouth good. Not traditional, but I can still get a decent bark on it and a decent smoke ring, and I don't have to watch the fire nearly as much.

On the one hand, I feel guilty for cheating, on the other hand - it's just really tasty. My friend from Georgia even gives it his stamp of approval.

Nathan - I am really looking forward to seeing your book, and I am finding the cash to order a copy. I am glad its a book and not an epub. Books are a paramount technology.

Apologies if my BBQ/Sous Vide method is in any way offensive and/or sloppy cooking. It's just the way I roll...

[umami5]

Hi all,
I have been searching through this thread and cannot seem to find a method or recommended quantities, temp and times for making/infusing oils. i am looking to make an oil flavoured with lemon or orange and possibly bergamot later in the season. An recommendations?
Thanks

[lesliec]

Hi, Umami5.

I hadn't thought of trying it sous vide, but I've had great success simply bringing oil plus whatever I'm infusing up to 90°C on the stove, keeping it there for a few minutes and letting it cool back down before bottling.

You'll find some things infuse more readily than others, and I can't offer any good suggestions on why that is. Rosemary, sage and bay all behave beautifully, but basil I've had to hit with an immersion blender to get the flavour into the oil (with a consequent loss of clarity). I've found lemon much the same; I can only conclude I might need a different recipe for some things.

As for quantities, I haven't found precision to be at all necessary. Last time I did 5 litre batches and just put a handful or two of the herbs in.

You haven't mentioned what SV equipment you've got. If it's something like a SVM/rice cooker combination, you have the option of putting your oil directly into the rice cooker or, for smaller quantities, you could try bagging oil and peel/leaves (don't drop the bag while you're trying to seal it!). I have no idea how an immersion circulator would handle oil going through it. Anybody?

[ChickenStu]

What are the pasteurizing conditions for ground beef again?

I looked back a handful of pages and then realized it would just be easier to ask.

[PedroG]

Depends on thickness of the burger or whatever, see Douglas Baldwins's table 5.8

[BadRabbit]

Hi, Umami5.

I have no idea how an immersion circulator would handle oil going through it. Anybody?

Lab quality (Polyscience) ICs have no problem with oil. A homemade setup with a fountain pump might not handle it as well though.

[PedroG]

A few replies to recent posts.

Hanging vertically is in general better than horizontal, because the water in contact with the food is cooled, which makes it slightly denser, so it sinks vertically (beacuse gravity points down). This process is called natural convection.

An extreme version happens with your freezer. Hold you hand below the door while you open it (assuming it has a vertical door), and you will feel the cold air pour out. For a freezer this is bad - it means you lose lots of cold air every time you open it. Chest freezers don't have this issue.

Anyway, in an unstirred bath like Sous Vide Supreme, natural convection is important source of movement, and in general it is better if you place food so that natural convection will be encouraged.

With a stirred bath (i.e. one with a pump) this is less important. The pump produces forced convection which in general dominates the much weaker natural convection. Natural convection is weaker because the temperature difference is generally pretty small so the density differce is pretty small too.

Of course these are generalities that apply to packing a bunch of flat items (say, a half dozen steaks).

If you have a spherical object, "horizontal" and "vertical" have no meaning! That is pretty much true for cylinders also. If you are cooking a whole squab, or a chateaubriand or some other cylinderical food, it really isn't going to matter that much. Also, if you have a small object in a large bath, it won't matter much.

The goal in all cases is to get good water circulation. Jamming the bath very full is a bad idea no matter what orientation is used.

Thanks, Nathan, for your clarifying post, and for your hints concerning visualization of convection currents.
I have conducted a few experiments confirming the importance of adequate positioning of the bag in the bath, see Sous Vide Wikia

The conclusions are:
* An uncovered water bath may lead to uneven temperature distribution by evaporation and consequent evaporation cooling of the superficial water layers.
* Uneven temperature distribution happens especially with insufficiently submerged items in horizontal position.

And my recommendations are:
* An open water bath should be covered by a plastic cover, hollow plastic balls (ping-pong balls), a styrofoam cover, or whatever, to avoid evaporation and consequent evaporation cooling of the superficial water layers.
* Vertical positioning of bags avoids the insufficient submersion that may occur with horizontally placed bags, and in case of multiple bags, it does not impede natural convection.
* A tall water bath as opposed to a shallow bath has the advantage of allowing even large pieces to be positioned vertically.
* Forced circulation (pump or aquarium bubbler) is desirable especially in shallow water baths (useful water depth less than 20cm, like laboratory water baths or SousVideSupreme).
* Bags floating horizontally in an unstirred and uncovered water bath must be avoided, as this may lead to uneven heating of the food, which is especially important in pasteurizing food. If horizontal placement is inevitable, adequate submersion must be ensured.

Furthermore, natural convection currents are very weak as soon as steady state has been reached and heating power is minimal, see
http://www.mydrive.ch/download/75349494/Heating_Full_Power_2000W.AVI
http://www.mydrive.ch/download/75350734/Steady_state_55C_no_cover.AVI
http://www.mydrive.ch/download/75352148/Steady_State_55C_with_cover.AVI
username: visitor@P.Gruber
password: visitor

[Dave the Cook]

More information on Modernist Cuisine over here.

[Chris Amirault]

Diving in here:

What are the pasteurizing conditions for ground beef again?

Depends on thickness of the burger or whatever, see Douglas Baldwins's table 5.8

Baldwin notes that this is for "thawed meat." Are the times identical for meat that's never been frozen?

[Chris Amirault]

I got some beef cheeks and, after reading through suggestions on this thread and elsewhere, decided to cook them at 60C for 72 hours. ... At the same time I threw some pork belly in the cooker for the same amount of time.

As I was not using the belly immediately, I cooled it rapidly in an ice bath and put it in the refrigerator.

To use the belly, I cut it into cubes. I then heated up a frypan until very hot and cooked each side of the belly piece until it was fully browned. The result was an incredibly tender piece of pork belly with a seared, crunchy, outside.

The dish that I wound up doing with the pork belly is on the dinner thread at this link. It will definitely be cooked again.

I think I want to give this a go as I have a very good pork belly source here. How did you season them, Nick? And did you keep the skin on them?

[KennethT]

I got some beef cheeks and, after reading through suggestions on this thread and elsewhere, decided to cook them at 60C for 72 hours. ... At the same time I threw some pork belly in the cooker for the same amount of time.

As I was not using the belly immediately, I cooled it rapidly in an ice bath and put it in the refrigerator.

To use the belly, I cut it into cubes. I then heated up a frypan until very hot and cooked each side of the belly piece until it was fully browned. The result was an incredibly tender piece of pork belly with a seared, crunchy, outside.

The dish that I wound up doing with the pork belly is on the dinner thread at this link. It will definitely be cooked again.

How did the fat turn out at 60C? Did it render at all, or even soften at that temp? This past weekend, I did pork shoulder for 24 hours at 68.5C and it came out great - really moist, and that fat had softened nicely. Did the meat in the pork belly turn out dry after being in the bath for 72 hours? I sometimes have problems with 72 hour cook times - it turns out nicely gelatinous, but the meat fibers themselves wind up being a bit dry... was that the case with yours too?

[DouglasBaldwin]

Chris,

Yes, it's the same. I probably should have put "not frozen" instead of "thawed"; but since I get my beef by the half, my mental image of beef is white-paper wrapped packages in our freezer with our name, the date, the cut, and the locker's name stamped on it.

When you (chamber) vacuum seal your formed, not-frozen hamburger patties, I recommend using a weaker vacuum setting (say 90--95%); if the patties are frozen, then you can use the 99% vacuum setting.

Diving in here:

What are the pasteurizing conditions for ground beef again?

Depends on thickness of the burger or whatever, see Douglas Baldwins's table 5.8

Baldwin notes that this is for "thawed meat." Are the times identical for meat that's never been frozen?

[Chris Amirault]

Makes sense. I wasn't sure if there are effects of freezing that should be taken into account with low temp cooking. Thanks.

[nickrey]

I'm not sure whether it was the cooking at 60C or the somewhat vigorous browning of the belly but both the fat and the meat were melt in the mouth tender and not at all stringy.

Edited by nickrey, 19 July 2010 - 06:28 PM.

[Chris Amirault]

Following Nick, just put in two skin-on belly strips (~1 lb each) that I rubbed with some shaoxing, dark soy sauce, sugar, julienned ginger, and white pepper. I'll revisit on Th.

[Chris Amirault]

Has anyone ever tried using low-temp cooking for tamales that have been sealed sous vide?

[slkinsey]

I wouldn't think that would work, Chris, unless you substantially changed the formula for the dough. The whole point of steaming tamales is that you make the dough with a ton of lard in it, and then when you steam them you melt out a lot of the fat and leave behind a somewhat spongy texture. Note how really good traditional tamales seem to have lots of tiny holes in them.