What Is a Pressure Cooker?
Technically, a pressure cooker is a stainless steel, or aluminum, pan that can be used on a flame or electric cooktop. It has a top that locks closed with a couple of valves on the top. While liquid boils and turns to vapor inside, the pressure rises and a valve on top (either spring-loaded or jiggly) opens automatically to let out excess vapor and maintain the pressure at about 15 psi – some pans give you the option to regulate the pressure.
Also, on the top of the pan there is a rubber or silicone safety valve that will pop out and release pressure in case the vapor valve were to clog (to avoid "explosions") and a safety latch to keep you from opening the pan while the pressure is still high inside (to avoid boiling liquid from spraying you). The bottom part of the pressure cooker can be used as a normal pan when you are not pressure cooking — mine is the perfect height to double as a pasta pot!
Pressure Cooking for Health
Vegetables cooked under pressure lose very few vitamins, minerals, taste and color compared to boiling. These guys stay in the food because the sealed top minimizes evaporation and the pan requires less cooking liquid to cook.
In fact, when adapting your recipes to the pressure cooker you only need to add a fraction of the liquid and salt.
What Can I Cook in a Pressure Cooker?
The things it can cook…
You can use a pressure cooker to cook vegetables, meat, fruits, fish, grains and it is famous for how quickly it can cook beans! A pressure cooker will let you cook any of the above in the following ways:
• Brown – this is the first step in many recipes, like risotto, and can be done before or the lid is placed, or after it is removed.
• Boil – just add enough water to cover the food by half.
• Steam - insert the accessory, or a metal-foldable steaming basket with ½” of water.
• Braise – brown the food in the pan, and then add cooking liquid (wine, milk, broth, water).
• Stew - throw everything in and close the top.
• Roast – place the meat and vegetables inside with just 1-2 cups of cooking liquid.
• Reduce – after the lid is removed, cook on high flame to reduce liquids if desired.
• Water Bath – place a heat-resistant bowl (ceramic, pyrex, stainless steel), covered in aluminum foil on steamer basket inside pressure cooker with 1 cup of water on the bottom.
I have heard of, but not tried, baking in the pressure cooker! Since this is so unusual, and there are very few recipes for it, I am not recommending you substitute your oven for your pressure cooker—though it sounds intriguing!
The Pressure Cooker & Energy
Save the planet, too!
It takes almost 90% more energy to cook at a rolling boil (HIGH heat) in a regular pan for an hour versus twenty minutes (LOW heat) in a pressure cooker- and the results are the same! A Vegetarian Chili which simmers for 11/2 to 2 hours in a regular pan cooks in just 30 minutes in a pressure cooker on low.
First, the temperature inside pressure cooker can rise to 250°F/121°C. This is a big deal because boiling water and its vapor can never go over 212°F/100°C. The higher temperature means that the cooking time is reduced to one third. Second, the sealed top of the pressure cooker allows for very little heat to escape, so once the pressure is reached (and the contents are boiling inside) the heat can be reduced to minimum.
The energy efficiency of this pan is the reason why pressure cookers are so popular in Italy and other countries, like India and Cuba, where energy for cooking is expensive! Almost every household in Italy has a pressure cooker and new brides usually receive their first as a wedding gifts — old broads can pick one up at the supermarket—as I did.
Buying a Pressure Cooker
How to choose one..
Your first pressure cooker should be a 6 quart / 5 liter – this is a large enough size for a family-of-four and has just enough space to double recipes to account for guests. The price can range from $50-$200. In fact, most pressure cooker cookbooks and online recipes are written for this size pressure cooker. You can’t go wrong with these features:
• Made of high quality stainless steel. This is naturally low-stick (even better if it is made in Italy or Switzerland).
• The bottom of the pan should have an aluminum disk (usually, it will be sandwiched between the body of the pan and a stainless steel saucer).
• A steamer basket accessory (or you can just buy a metal one, separately, that folds open and closes like a flower)
I don’t recommend that you buy a used pressure cooker unless it has an instruction manual (each manufacturer has its own quirks) and the following features: a safety valve (usually of silicone or rubber), and a locking handle (mine has a little thing that pops up when the pan is up to pressure that blocks me from accidentally opening the pan).
Inside Tips for Pressure Cooking
A few last tips…
If you decide to get one right now here are a few things I picked up on my own that were not written in the instruction manual of my pressure cooker:
• Recipe timing starts from the time the pan has reached pressure and begins to “whistle” — usually a couple of minutes.
• Actually, pressure cookers do not really “whistle” – it’s more like a hiss.
• Unless otherwise noted, start the pressure cooker on high heat (for about two minutes) until it reaches pressure (when it begins to whistle) and then lower the flame to minimum.
• You can open the pan by: 1. Letting the pan sit, off the flame, with the top on until the pressure comes down naturally (about 20 minutes). 2. Opening the pressure valve and releasing the vapor (about 2 minutes). 3. Placing the pan in an empty sink and running cold water on the top while the pressure valve is releasing vapor (about 30 seconds).
Happy (pressure) cooking!
Hip Pressure Cooking
About Laura: Laura Pazzaglia has lived in three counties in the last four years and, now, can be found living near Rome in Italy. In her previous career she was a technical project manager for large software corporations and a small urban metropolis. She has written regularly in her personal blog, which no one reads, since 2003. The recipes were piling up as her fascination for the pressure cooker grew so she decided to start a blog, Hip Pressure Cooking, with the sole purpose of educating and inspiring others to use their pressure cookers more often by posting unexpected and delicious recipes with easy-to-find ingredients, in both U.S. & metric measurements with vivid step-by-step photographs.
(Images: via Laura of Hip Pressure Cooking)