A Beginner's Guide to Pressure Cookers
The prospect of 15 pounds per square inch of steam heat that will soon be building up in the pressure cooker on my kitchen stove has me rattled before I even get the thing fired up. I have, I feel, done less dangerous things in my career—like luging, for example. My friends and family don't help matters. One pal cautions, "It's that constant, almost menacing rocking and hissing of the valve that totally keeps you on edge." My mom, whose new pressure cooker I borrow for this little experiment, left a helpful Post-it note saying, "Don't want to scare you but it needs respect." When's the last time someone lent you a toaster with a cautionary Post-it note? (Rhetorical question, since this has never happened in the history of the world.)
There's no denying, however, the appeal of the pressure cooker: slow cooking done faster. Water and steam under high pressure can reduce cooking times by up to 70 percent, which means, at least theoretically, that you could cook a whole chicken in 20 minutes or a potato in eight minutes (theoretically, because some of the setup can add time to the process).
The science is pretty straightforward: Pressure increases the boiling temperature of water. In your unpressurized Dutch oven, water can only heat to 212°F. In a pressure cooker, water, sealed inside a strong pot, can heat up to 250°F before boiling. Imagine climbing to the top of Mount Everest and discovering that water, at such low atmospheric pressure, boils at a measly 160°F or so; should you decide to boil some coffee up there, it would not be piping hot.
There's nothing new about the pressure-cooker concept—it dates at least to the 17th century. Indeed, it carries the whiff of an old-fashioned, fusty method used long ago by addled cooks who caused occasional minor explosions. The old cookers had pretty simple safety valves on them and a reputation for potential disaster. So before I get cooking with my mother's new machine, I look for reassurance from Michael Schlow, a man who knows a thing or two about cooking under pressure. The James Beard award--winning chef and owner of four restaurants, including Boston's Radius, competed on last year's Top Chef Masters.
"Here's the thing," says Chef Schlow after I've filled him in on my mounting fears about pressure cooking. "It might be time to retire grandma's pressure cooker and invest in a modern one. The modern ones have gaskets on the outside, locking handles, and pressure release valves, so they won't explode on you. As long as you carefully follow the directions, you really don't have to be afraid of it."
What's more, he finds its uses are myriad. "While I'm a big fan of low and slow cooking, there are times when you need to get something done in a hurry, and that's when a pressure cooker really comes in handy," he says. "Speed is its main calling card, but it's also that one-pot, no-mess idea. Fall is coming up, and a pressure cooker is a great way to put out cool-weather dishes like braised lamb and osso bucco without having something on the stove for five or six hours."
Schlow says when you're dealing with any sort of braise, normally you wouldn't want the ingredients to boil away fiercely, as it could result in tough, dry meats. "But somehow the pressure cooker throws that ideology out the window, creating instead a moist, delicious stew."
Nice advice, but Schlow's a pro and I wanted to hear from a home cook about cooking under high pressure. I called Patti Erickson, a teacher and avid home cook from Denver, whom I found at Cooking Light's Facebook fan page. Patti has been using a pressure cooker for almost 20 years. She switched to a new model five years ago.
"I mostly use mine for Mexican food because it's so quick and it makes the meat incredibly tender," she says. "I make big batches—fiesta cooking for friends, like chicken for tacos, refried beans, and green chili. But you can also use it for one person; just throw in a chicken breast, and it works beautifully." Patti also mentions that you can cook foods from frozen, which I find particularly practical. "Don't be afraid, Amy," she coaxes. "It's easy and it's fun!"
It's time to get pressure-cooking. I read over my simple recipe 27 times before feeling confident enough to scrub some beets. I add them and some water to my mom's 6-quart pressure cooker; I line up the handles and lock the lid in place with a reassuring click. Then I crank up the heat on my stove and run clear across the kitchen.
As the water heats up, the cap on the lid starts to rattle and release little sputters of steam. This is alarming. It is also normal as pressure continues to build inside. Eventually I tiptoe back over to the stove to regulate the temperature. This is all done by instinct, as I had the instruction manual with my mom's pressure cooker, but what she told me is that the temperature has to be kept high enough so the pressure valve continues to sputter and release steam every so often. In other words, if my stress level went down, the heat likely wasn't high enough. Within moments the air is filled with the earthy scent of cooking beets as the steam perfumes the kitchen—and just 10 minutes after that, my timer goes off.
I move the pot off the burner to let it cool for about 10 minutes before pulling on the pressure-release knob to immediately release a plume of steam that helps to further stop the cooking process. (Some people, though, use the secret trick, which Chef Schlow mentioned, of placing the closed cooker under cold running water to cool it down even more quickly.)
I triple-check that the pressure indicator has dropped down—visual proof that there's no more pressure in the pot and that the lid is no longer locked onto the base. I carefully unscrew the lid and open it so that the remaining puffs of steam escape safely at the back of the cooker. I touch my face, hands, and legs: I'm still alive. I finish the recipe by running the beets under cold water and peeling and slicing them before tossing the 10-minute-cooked beets with my zippy dressing along with some fresh dill and walnuts. I am eating my beet salad moments later. And it's delicious—the fresh dill totally makes it. Shaving 35 minutes off the cooking time didn't hurt, either.
The next day I make a chickpea and chorizo soup. This recipe calls for sautéing onions, garlic, and chorizo in the open pressure cooker pot. Then I add the rest of the ingredients, including chicken broth and dried chickpeas, to the pressure cooker, screw on the lid, and bring it up to pressure. I'm now feeling confident enough to watch an episode of Modern Family while the chickpeas cook, occasionally checking back to make sure the pressure level is maintained by listening for and watching that telltale pressure release valve. It's that simple: A stew made from dried chickpeas that would have taken nine hours (including chickpea soaking time) has magically taken only one.
And it's amazing how much flavor the pressure cooker has wrought from garlic, chorizo, and chickpeas in 60 minutes. The chopped escarole stirred in at the end is a perfect foil, the pleasantly bitter greens making the dish especially satisfying.
I am in one piece. And I am a pressure cooker convert.