How to control the temperature of water for an extended period of time

cooking-timeequipmentsous-videtemperature

When making the "perfect" mash, Heston Blumenthal recommends cooking waxy spuds in hot water for half an hour at the temperature of 72 degrees Celsius, exactly. At 75 degrees stuff starts breaking down.

I would like to try this out but am unsure how I can keep the temperature constant.

What kitchen tools and process can I follow to measure the temperature throughout the process? Are there any tricks?

Best Answer

You can try to set up my at-home on-the-cheap monkey-at-the-controls sous-vide machine. I take a nearly full 22 quart stock pot with an analog instant read thermometer to monitor the temperature and watch the temperature and adjust the dial accordingly.

With this only needing 30 minutes you probably just want to get the water to exactly 72 degrees C and then immerse the potatoes without adding any heat. The amount of energy in 20 quarts of water is phenomenal and you won't lose a lot of heat to the air.

Alternatively you could get 72 degree water and a beer cooler and try that way for the extra insulation.

Related Solutions

Oven – the best time and temperature for taste when cooking a salmon fillet in the oven

When you're determining the doneness by time, you're doing it wrong :)

There are too many differences between individual fish to go just by weight, thickness, oven temperature, and time. The best way is to measure the internal temperature (stick a thermometer into the thickest part of the fillet); I like about 120 F (50 C) for salmon (carryover cooking raises the temperature a little higher after taking it out of the pan), but then it has to be good quality fish. You need to check early and often, because it can go from undercooked to overcooked fairly quickly. Now, like zanlok says, my experience is mostly with pan frying, and I'd expect using the oven would be a bit slower than using a pan because of slower heat transfer; so you should be a bit safer.

If you don't have a meat thermometer, an easy way to test fish for doneness is to look for translucency. Salmon can still be just a little translucent in the middle. Also, properly done fish flakes along the natural "seams". Another nice trick (which doesn't work for boneless fillets - sorry) is to find a bone in the thickest part of the fish: if it comes out fairly easily, then the connective tissues have mostly dissolved and it's done.

That leaves the temperature for your oven. I would go with very high - that way the fish gets the least possible time to dry out (which is going to be a big risk with this cooking method, I would think - unless you wrap your salmon in bacon or something like that). At a guess, I'd try 450 F (230 C).

Time vs. Temperature – What changes what

One fundamental error in this question: 400 degrees is not twice as hot as 200 degrees. Temperature is a measure of the kinetic energy of the particles involved. The only scale on which you can do the kind of ratio you are imagining is Kelvins - you have to measure from absolute zero.

400 F = 477.59 K
200 F = 366.48 K

so the kinetic energy of the air in the oven is only about 477/366 = 1.3 times as high at 400 F as it is at 200. For simple cases, like how long it takes to evaporate a pan of water, 1.3x is probably pretty close to right, but as is pointed out above, there are a whole host of other variables that come into play with real food.

So ...

Bake time variations for a recipe that calls for 400 degrees for 30 minutes converted to a 450 cooking time and a 350 cooking time:

400 Farenheit = 477.594 Kelvin

477.594 x 30 minutes = 14327.82 HeatPoints

450 F = 505.372 K

14327.82 HP / 505.372 K = 28.35 or 28 minutes 21 seconds

Best Answer

Related Solutions

Oven – the best time and temperature for taste when cooking a salmon fillet in the oven

Time vs. Temperature – What changes what

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