Pressure cookers are powerhouses of culinary innovation. Though they have a rich history and relatively straightforward scientific explanation, confusion about how they work and what they're good for abounds. I've already answered the question of how pressure cookers work, including how they’re designed, the important safety features included in newer models, and the intimate relationship between pressure and temperature. The long and short of it is that pressure cookers allow you cook your food at higher temperatures, which in turn speeds up your cooking.
But a pressure cooker isn’t just a tool for cooking things faster. In fact, the high temperature and high pressure inside a sealed pressure cooker are ideally suited for a number of culinary applications. Let’s break it down.
Extract Gelatin and Flavor for the Best Stocks Ever
The pressure cooker is the MVP of making stocks. Take Daniel’s pressure cooker chicken stock, for example. Making chicken stock on your stovetop requires at least a couple of hours of careful simmering. With a pressure cooker, you can have a richer, more intense stock in under an hour.
There are two reasons for this. First, the higher temperature extracts flavor from meat and vegetables quickly. Second, since collagen in the presence of water begins breaking down into gelatin starting at temperatures as low as 160°F (70°C)—and accelerates as temperature increases—the high temperature in a pressure cooker converts the collagen in connective tissues to gelatin in a flash. Gelatin is the key to a rich stock with a thicker body and velvety texture.
There’s another advantage to cooking stock in a pressure cooker: Because you’re cooking the chicken stock at high pressure, the contents never really come to a boil, so the cooking is gentle.* This stillness produces a clearer, cleaner stock, one that resembles consommé, where an egg raft is used to separate out the denatured proteins and impurities that typically make stock cloudy when agitated or mixed.
*The contents never boil as long as (a) you don’t allow a pressure cooker to over-pressurize and vent, and (b) you don’t employ the quick-release method to depressurize the pot.
Tenderize Tough Cuts of Meat on the Fly
That same collagen-rendering heat is what makes the process for Kenji’s recipe for pressure cooker pork chile verde so simple and fast. The tough pork shoulder meat becomes meltingly tender in just 45 minutes, as opposed to the hours it would take to get it tender with simmering. The same principle can be applied to cooking other tough cuts like beef chuck, pork belly, or even oxtails.
Cooking Rice, Grains, and Beans
Rice is finicky, and it takes a while to cook. The grains have to absorb water, and heat is required to break down starches to soften those grains. If you don’t want mush, you have to pay close attention to the ratio of water to rice, regulate heat, and account for evaporation, depending on the cooking vessel. A pressure cooker removes many of those variables and speeds up the process considerably. For instance, Kenji’s pressure cooker mushroom risotto only takes five minutes to cook the rice to a perfect al dente, compared to the 45-plus minutes it takes following a more conventional method. And, because there’s no evaporation, you can dial in the amount of cooking liquid (and you can use far less), resulting in a consistent texture, every time. There’s virtually no guessing and no eyeballing involved. Finally, the absence of any agitation in the pressure cooker provides a gentle, still cooking medium for the rice, which helps to keep individual grains intact and separate.
The same principle applies to other grains as well, although the payoff isn’t as dramatic. For instance, wheat berries take a notoriously long time to cook using conventional methods—upwards of an hour and a half on the stovetop. Some sources say that a pressure cooker cuts that time by more than fifty percent, to 40 minutes. Barley can go from 50 minutes to less than twenty, and farro can be cooked in less than eight minutes. The catch? Daniel found that using a pressure cooker on whole grains like farro, wheat berries, and whole-grain spelt did cut down on cooking time. But after factoring in the time it takes to pressurize and depressurize a pressure cooker, he found you only really save about 10 minutes compared to a more conventional method.
Grains not your thing? A pressure cooker slaps with beans and legumes, too. Kenji’s quick and easy pressure cooker black beans recipe cuts the cooking time from three hours to 40 minutes—no pre-soaking and no baking soda required.
For both grains and beans, one disadvantage to pressure cooking is that there’s no way to monitor the contents once things are cooking. You can’t just quickly open up the pot without depressurizing and re-pressurizing again. Instead, cooks must rely on recommended cooking times. If foods don’t cook in the recommended time, you’ll have to bring the pot back up to full pressure to keep cooking.
Pressure Caramelization: Wet Maillard Reactions
Under certain conditions, a pressure cooker can actually speed up Maillard reactions that otherwise wouldn’t happen at normal atmospheric pressure and temperature.
Maillard reactions are the cascade of small chemical reactions, catalyzed by heat, that occur between proteins** and sugars, which produce new flavors, aromas, and colors. Most of the time, these reactions require heat in excess of 300°F (150°C) to happen quickly and readily. But there’s evidence that Maillard browning can happen at even lower temperatures, given enough time. Anecdotally, we see this happen when a chicken stock darkens as it cooks—and becomes even darker still as you reduce it to a demi-glace consistency over the course of a few hours, which is probably both a function of concentration and Maillard browning.
**Technically, the amino acids that make up proteins.
Why would you want to go to the trouble of making Maillard browning happen in a pressure cooker? In general, Maillard reactions occur alongside dehydration. In an open system (like an oven) with free evaporation, heat drives off surface moisture and allows temperatures to exceed the boiling point, which facilitates Maillard browning. Cooking in this way leads to crisping and crunching—and even burning if taken to an extreme. In a pressure cooker, there is zero evaporation, so you can have Maillard browning throughout, without drying out surfaces first. The resulting browning is also distributed more evenly throughout the food, not just on the surface.
To speed up Maillard browning in a pressure cooker, it’s often necessary to raise the pH to create a basic or alkaline environment, which increases the speed of reactions by making amino acids more reactive with sugars. In fact, “pressure-caramelization” (admittedly a bit of a misnomer, since it’s really a Maillard reaction at work, not caramelization, which is a different reaction altogether) is a technique popularized by Modernist Cuisine: By adding baking soda to a high-sugar vegetable or fruit and cooking under pressure, the food undergoes significant Maillard browning. Kenji takes advantage of this technique for his pressure caramelized onions. You still won’t get true caramelization (which is why Kenji opts for a quick post-pressure cook), but it’s a quick way to get that initial browning and flavor at a relatively lower temperature.
You can “pressure-caramelize” almost any fruit or vegetable, although don’t expect them all to be winners. Sweet potatoes and carrots work beautifully, but Daniel doesn’t really recommend pressure-cooking butternut squash, which somehow tastes like pretzels. If you’re a fan of banana bread, I highly recommend pressure-caramelizing bananas for an added layer of intense, butterscotch-like flavor.
Canning and Preservation
Let’s not forget one of the original uses for pressure cooking in general. High pressure and high temperature are ideal for forcing out unwanted oxygen and killing pesky microbial baddies when canning foods. Pressure canning is well suited for foods that are low-acid (higher than 4.6 on the pH scale), or require high heat to kill anaerobic microbes such as Clostridium botulinum. To properly do so, you should invest in a pressure canner, which features a gauge that allows you to more accurately track pressure.
If you want a more comprehensive (and wonderful) explanation of pressure canning and preservation, Christina Ward’s guide to the science of canning is all the nerding out you could ask for.
The Limit Does Not Exist
Is there anything a pressure cooker can’t do? We have yet to explore some lesser-known applications. KFC is famous for popularizing industrial pressure-fried chicken. Could you do it at home? Probably. But should you? Probably not, unless you love ruining kitchen equipment and dealing with blazing hot oil. Then there’s pressure cooked seeds: Dishes like sunflower seed “risotto” or pumpkin seed mole, which use the pressure cooker to produce otherwise unachievable textures. I’m probably missing several more techniques, but I’ll leave that to the geeks out there.
Hopefully, you’re now convinced that a pressure cooker is a useful—essential, even—tool that you should have in your kitchen. Armed with all this knowledge and pressurized power, I encourage you to cut loose and pressure-cook everything in sight. And if you’re ever in doubt, keep this in mind: If something usually takes a long time to cook, doesn’t need a ton of dry heat, and has a good amount of moisture when cooked, it’ll probably do great in a pressure cooker.