Re: RePost: Pressure cookers revisited

[Guest guest]

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> >

> > Bee, thank you for all you do for us! Concerning pressure cookers:

> >

> > Jan, 2008, msg #46890, you say pressure cookers are OK.

> >

> > in this Jan 2010 msg #84484 , you state: " do not use a pressure cooker

since it is very high heat. Just simmer bone broths on low heat. The time it

takes is very important for pulling out minerals from the bones.

> >

> > Also it is important not to cook meats on high heat, since it makes the

protein molecules bind closer together and lose more moisture so it is more

difficult for us to digest. Protein digestion is a process which breaks apart

protein molecules. "

> >

> > Pressure cookers were brought up on another forum i'm on. One person said

this: " Meat cooked under pressure becomes very tender so it should be easier to

digest, not harder. "

> >

> > A pressure cooker boils water at 250 degrees rather than the standard 212

according to Lorna Sass. We bake a roast at 325 in the oven so I don't

understand how 250 is too hot. "

> >

> > Will you clarify your stand on using pressure cookers, please?

+++Hi ,

There are two main methods of cooking foods: Dry Heat and Moist Heat.

Dry heat cooking refers to any cooking technique where the heat is transferred

to the food item without using any moisture. Dry-heat cooking typically involves

high heat, with temperatures of 300°F or hotter.

Baking or roasting in an oven is a dry heat method because it uses hot air to

conduct the heat. Pan-searing a steak is considered dry-heat cooking because the

heat transfer takes place through the hot metal of the pan. Note that the

browning of food (including the process by which meat is browned, called the

Maillard reaction) can only be achieved through dry-heat cooking. Examples of

dry-heat methods include:

Roasting & Baking

Grilling & Broiling

Sautéing & Pan-Frying

An oven thermometer will give the temperature of your oven and not the

temperature that it has been set to. That's why Chefs use 2 meat thermometers.

One for the oven, and a meat thermometer to stick into the meat to check inside

temperature.

Moist heat cooking methods include any techniques that involve cooking with

moisture — whether it's steam, water, stock, wine or some other liquid. Cooking

temperatures are much lower, anywhere from 140°F to a maximum of 212°F, because

water doesn't get any hotter than that. Examples of moist-heat cooking methods

include:

Poaching, Simmering & Boiling

Steaming, however Pressure Cookers increases heat above 212°F

Braising & Stewing

A pressure cooker uses moist heat, which is steam, so it doesn't actually boil

foods in water. When meat is cooked above 212°F (100°C) water in the meat

begins to evaporate into steam (meat starts to lose moisture).

The point of cooking meat is to bring out its flavour and to make it tender

enough to eat, which also pre-digests it. But you do not want to cook meat so

it loses moisture or so the molecules in it bind close together like you see on

the surface of steaks that are seared or burnt (that outer surface is very tough

and hard to chew).

For cooking purposes, meat consists of, among other things, lean tissue,

proteins, collagen and water (usually around 75%). Collagen exists in flesh,

bone and connective tissue, and is very important to the cook because the amount

of collagen in a piece of meat will determine the length of time it should be

cooked for.

If meat is cooked at 212°F (100°C), the pressure caused by the evaporation

obliterates the meat, and any juices left in it disappear.

Temperature Cooking Stage

104°F (40C) Proteins in meat start to denature - see my note.

122°F (50C) Collagen begins to contract.

131°F (55C) Collagen starts softening.

158-167°F (70-75C)The meat no longer holds oxygen and turns gray.

212° (100 C) Water in meat begins to evaporate into steam.

Source: http://missvickie.com/howto/meat/tough.html

Bee's Note on Denature and Denaturing: Denaturing means the molecules in the

meat are being broken apart, also called unwinding or unfolding of protein

molecules. Protein molecules in raw meat are bound close together, often in

chains.

Imagine crunching up a beaded necklace into a tight ball in your hand versus

allowing it to unwind or unfold into a long chain. When protein molecules are

denatured it means they are no longer in a tight ball.

During digestion protein must be denatured in order to separate out each kind of

protein in it called amino acids. So denaturing is the chemical breakdown of

protein your body must do in order to utilize and absorb protein.

Therefore denaturing meats pre-digests them for us, making them easier to

digest. Meat is pre-digested when cooked, marinaded, cured, etc.

The higher the level of connective tissue, the longer the meat will need to be

held in the temperature range of 131°F (55°C). So, when cooking meat, you will

first need to decide whether or not it has a high amount of connective tissue.

All cuts of meat that have had to do some work - oxtail, shin and shoulder, for

example - will have more connective tissue, and require long, slow cooking.

Leaner cuts, such as steaks and chops, require less time at this temperature,

although they still benefit from slow cooking.

So that's why I do not recommend cooking meats in a pressure cooker.

All the best, Bee