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" What is the difference between a pressure cooker and a slow cooker? "

Hello. Please tell me the difference between a pressure cooker and a slow cooker. Which one I should use to cook very tough meat? Thank you.

—Lesley Just, Dar es Salaam, Tanzania


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Hi Lesley,

Both slow cookers and pressure cookers do a good job of tenderizing tough meat, but each makes meat more edible in a different way.

A pressure cooker is an enclosed pot with a lid that locks to form an airtight seal. When a small amount of liquid inside the pot boils and produces steam, the pressure cooker traps the steam inside. As pressure builds, water boils at higher and higher temperatures. At 5 pounds pressure, water boils at about 228 °F (108 °C). At 15 pounds pressure, the boiling temperature rises to 250 °F (121 °C). When you consider that water usually boils at 212 °F (100 °C) and the food inside a pressure cooker is at much hotter temperatures than normal simmering will allow, it's not surprising that food cooks quickly.

There's another aspect of pressure cookers to consider too. Steam penetrates food easily under pressure. So connective tissues in cubes of beef for soups or stews soften in 15 minutes or less, and a pot roast will be medium-rare in 30 minutes.

Be sure to follow instructions carefully; at this speed, it's easy to overcook things in mere minutes. You may find that flavors aren't as fully developed as when tough meat simmers in a slow braise But you do save a lot of time.

A slow cooker is a countertop appliance—basically an electrified pot with a lid that's designed to cook at low temperatures for long periods of time. Though very different from a pressure cooker, slow cookers are also good for tough cuts of meat. It's best to begin on the highest setting for the first hour of cooking (to raise the temperature quickly) and then reduce the setting to low. Slow cookers work well for soups and stews where less-tender cuts of meat are cut into chunks or small pieces. They are not appropriate for large pieces of meat such as roasts, as the heat penetrates too slowly to ensure safety.

So how does slow cooking tenderize? Broth, water, or juices are always added along with the meat. The moist heat they provide softens the connective tissue that binds the muscle fibers in the meat, helping it to fall apart more easily. And when the heat is kept low, as it is in slow cooking, the proteins in the muscle are less likely to overcook, so the meat stays moist as well as tender. Flavors are also more developed, but the process takes considerable time.

If you have a pressure cooker and a slow cooker, we encourage you to try both. We'd be interested in your results and comments, as would many members of our Forums.

Anne and Sue




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