Pressure cooking is a type of cooking that saves time and energy, two rare commodities in this day and age. Sure, they may still make the 'psst, psst, psst' sound, but they are safer than ever.
Can you believe that in ten years of publishing Ricardo magazine, this is the first time we have cooked using a pressure cooker? Very popular at one time, this appliance has taken a back seat to the slow cooker in recent years, even though they work differently. But they have one thing in common: they tenderize meat to perfection.
Cooking time varies from one pressure cooker to the next. Do you have a 50 kPa, 70 kPa or 103 kPa pressure cooker? It’s important to know this detail. Our recipes were developed with an electric pressure cooker that reaches 60 kPa.
Forget the horror stories your grandmothers experienced, tales of exploding lids and sauces sticking to the ceiling! New generation pressure cookers are better designed and safer than those of yesteryear. For example, lids are equipped with dual safety valves to prevent overpressure, as well as an interlocking system that prevents the lid from being opened while the pressure cooker is pressurized. However, as with any other kitchen appliance, there are precautions that need to be taken. These are clearly explained in the user manual, which is important to read and understand before using this appliance for the first time.
2. Good investment
If you decide to go the pressure cooker route, it is best to invest in a new model, rather than risk using one that has been lying around for several years. Expect to pay between $100 and $400, depending on the capacity, the finish (aluminum or stainless steel) and its options (one or two pressure levels, locking system, etc.) This is a worthwhile investment, as new models are significantly safer.
The principle behind the pressure cooker is quite simple: it increases the boiling point of water. At normal atmospheric pressure (at sea level), the boiling point of water is 100 °C (212 °F). But in a pressure cooker, the pressure gradually rises because steam is trapped inside the cooker by its hermetically sealed lid. Just enough steam is released by an over-pressure valve to maintain the desired pressure. Due to this pressure increase, the boiling point of water moves from 100 °C to 121 °C in a stovetop model that operates at 103 kPa (15 psi). Electric-type pressure cookers operate at a much lower pressure, between 50 kPa (7 psi) and 80 kPa (11.6 psi), generating boiling temperatures from 112°C to 117 °C. The RICARDO pressure cooker operates by default at 60 kPa (8.7 psi), for a boiling point of 117 °C.
Since the boiling point of water is higher in a pressure cooker than at normal atmospheric pressure, food cooks faster. A stew, for example, takes about 12 minutes, a whole chicken around 15 minutes, chicken breasts 4 minutes, whole potatoes 10 to 15 minutes. Even legumes, which normally take 1.5 to 3 hours to cook, soften in less than 30 minutes in a 103 kPa pressure cooker. There’s no doubt that this allows us to spend less time in the kitchen. Obviously, these cooking times will vary depending on the pressure that each appliance reaches.
Inexpensive, tough cuts of meat, such as stewing cubes and roast shoulder, palette or rump, literally melt in your mouth after being cooked in a pressure cooker. This is because collagen transforms into gelatin. Collagen is the elastic, tough material that surrounds muscle fibres in meat and holds them together. Heat transforms this collagen into melted gelatin, by breaking the chemical bond between molecules. This magic can happen two ways: by slow cooking at low heat (the crockpot principle), or by cooking quickly at high heat (the pressure cooker principle). In both cases, lower quality meat (a more economical value) turns out tender and tasty.
Sure, it can't grill steak, but anything you would normally make in a pan or casserole dish can be easily prepared in a pressure cooker, in less time: broth, soup, legumes, rice, cereal, pasta, stew, vegetables, stewed sauce (compote)... you can even make individual portions of rice pudding or flan, using mini ramekins.
You think pressure cookers are old fashioned? Guess again! New recipe books created especially for pressure cookers offer surprising choices, from appetizers to dessert. Ideas that go beyond the usual stews, Swiss steak and hunter's chicken dishes of old. There's ratatouille, stuffed vine leaves, bortsch, cassoulet, tajine, curry, osso buco, cheese cake, chocolate cream pots, bread pudding and more.
Using a pressure cooker can reduce energy consumption (gas, propane or electricity, whatever the case), because it takes up to 70% less time to do the job. This is a significant factor for those pressed for time!
Oxygen, time, heat and water are four enemies of vitamins. However, there is limited contact with air in a pressure cooker, cooking time is considerably reduced and it requires less water than cooking in a regular saucepan. In one shot, food's nutritive value is better preserved, in particular that of fruit and vegetables. Studies of cooked vegetables have shown that a pressure cooker retains more vitamin C (a water-soluble vitamin) and carotene (a fat-soluble vitamin) than boiling, whether in a large or small amount of water.
There is a pressure cooker (also called an autoclave) specially designed to can low-acid food, such as vegetables (beans, peas...), and recipes for meat, poultry or fish (stew, spaghetti sauce, etc.). The autoclave works at a higher pressure than a traditional pressure cooker and is fitted with a rack that allows you to stack two or three rows of jars. It is therefore less practical for regular use than a pressure cooker. It will set you back between $150 and $200.
Presto vs. Crock-Pot
A slow cooker works differently than a pressure cooker. When a slow cooker is set to low, its temperature reaches around 85°C, or a low simmer. When it is set to high, the temperature of the food in the slow cooker never exceeds 100°C. Therefore, the food cooks slowly, over a period of 4 to 8 hours, depending on the selected heat setting. It’s the other way around in a pressure cooker: pressure inside the cooker increases the boiling point of liquid to up to 121 °C. So food cooks quickly in a small amount of time. Both appliances are great for tenderizing the toughest meat.