A pressure cooker reaches cooking temperatures above the boiling point of water (212 F. or 100 C.). Pressure cooking involves time to bring water to a boil, reach cooking temperature, and a period at the operating pressure and temperature. Pressure cookers use high heat to build pressure and get food to a cooking temperature; low heat to maintain heat and pressure. Pressure cookers have sealing lid and valves. The lids are metal with locking rims. The cook cannot see what is going on an monitors the events in the pot by watching valves pot shut and by readouts in electronic models.
Recipes for pressure cookers state the cooking time as the period under operating pressure. Recipe will address how to release pressure. Pressure cookers have two working valves (many have additional emergency or safety valves):
- Float valve: responds to steam pressure, pops up to seal the lid and engages a lock to prevent opening the lid while the device is under pressure; and
- Pressure Release valve, also known as pressure limit valve, pressure regulator knob, steam release hande, steam release reset button, rapid release button.
Pressure will drop when the heat is removed, or when the pressure release valve is opened. Some recipes call for a natural drop before the valve is opened. This is commonly a a step in cooking rice and grains – and part of cooking. Other recipes call for opening the valve when the full heat/pressure period ends.
Most devices have low and high pressure settings . The American standard for high pressure limit is 15 psi; the European standard is 1 bar, or 14.6 psi. Stovetop pots tended to go to those limits, although many models did not. Stovetop pots were the standard for most recipes until electric pressure cookers became more common in the last decade of the 20th century.
A stovetop pressure cooker uses an external heat source. Stovetop pots are expensive compared to some cookware but many good models are less expensive than electric pressure cookers. A stovepot pot can be heated to pressure quickly using high heat. A stovetop pot can saute, fry and simmer. The stovetop pot requires the cook’s attention: to turn the stove down when operating pressure is reached, and then to turn off the heat when the pressure period ends.
Electric pressure cookers and pressure multi-cookers have become popular but have not pushed stovetop pots out of the kitchen or the market.
An electric pressure cooker has an outer shell, a heating element, an inner pot, a sealing lid and a control set. A modern machines has a microprocessor and an electronic control panel. The device turns the heating element on to sauté or build pressure. When operating temperature and pressure are reached, it cycles off and on to maintain pressure and temperature. The device will turn the heat off at the end of the period entered as the cooking time (at the operating pressure), and sound an alarm.
Electric pressure cookers cook at lower pressure and temperature than the upper limit(s); but above the boiling point. Laura Pazzaglia’s Hip Pressure Cooking FAQ observes that
Electric pressure cookers build pressure up to 15 psi but then maintain a lower pressure during the cooking … the “operating pressure” is 11.6 even though the cooker reaches 15 psi while it’s building pressure.
‘Operating Pressure’ is the true pressure at which an electric pressure cooker cooks“.
There are exceptions; e.g. – Instant Pot Max, marketed in 2018, is said to operate at the standard pressure.
Laura Pazzaglia’s Hip Pressure Cooking site has a FAQ which includes the pressure/temperature graph. The lower pressures of electric pressure cookers require an adjustment to cooking times from standard recipes. Laura Pazzaglia has charts on a cooking times page at her Hip Pressure Cooking site. Her charts recognize that there are differences between stovetop and electric machines and different brands and machines by leaving some parameters within ranges. Some writers provide notes about performance on some recipes in specific devices.
An electric pressure cooker provides the option of cooking without the pressure sealing lid using a sauté setting (or any hot setting that can be activated without locking the lid). Some have multiple saute (the device serves as an electric skillet) settings, some have only one saute setting. This is a way to use the device to cook some ingredients (e.g. softening onions and “blooming” spices and garlic and ginger) before filling the cooking pot and starting the pressure cooker. Using these settings to cook ingredients that have to be removed and added later is less convenient – it may be better to use the pressure cooker pot for other prep steps and pressure cooking, and manage the saute item in a skillet or wok on the stove. An electric pressure cooker is narrow and tall, and not easily handled and used like skillet. A user may needs to able to continuing cooking after the pressure cooking has ended – some final simmering to reduce a dish or cook ingredients added after the pressure cooking. The sauté setting may be too hot for anything less than a full rolling boil. Electric pressure cookers need – and most have – a simmer setting or an equivalent.
Recipe books and web sites for pressure cookers, electric pressure cookers, and multi-cookers:
|Cooking Under Pressure||Book||1989||Lorna J. Sass||Goodreads||Stovetop "standard" recipes, have to be adjusted for lower pressure devices|
|hip Pressure Cooking||Book||2014||Laura Pazzaglia||Goodreads||Pressure recipes: standard and electric cooking times|
|hippressurecooking.com||Web||Laura Pazzaglia||Pressure recipes: standard and electric cooking times|
|MaoMaoMom Kitchen||Web||[eponymous]||Instant Pot recipes|
|Vegan under Pressure||Book||2016||Jill Nussinow||Stovetop standard recipes|
|Dinner in an Instant||Book||2017||Melissa Clark||Instant Pot recipes|
|The Electric Pressure Cooker Cookbook||Book||2017||Barbara Schieving||Goodreads||Electric device recipes|
|Pressure Cooking Today||Web||Barbara and Jennifer Schieving||Electric device recipes|
|Instant Pot Recipe Booklet||Booklet||2018||Instant Pot corporate; various contributors||Instant Pot recipes|
|Multicooker Perfection||Book||2018||Cook's Illustrated (America's Test Kitchen)||Electric device recipes|
|Madhur Jaffrey's Instantly Indian Cookbook||Book||2019||Madhur Jaffrey||recipes from Indian cooking books for Instant Pot|
Jill Nussinow, writing mainly about vegetables, provided standard pressure cooking times. She thought that electric time did not have be lengthened where the release is slow or natural – the device provided extra cooking time because electric pressure cookers provide a little extra cooking time coming to pressure and while the pressure drops.
Laura Pazzaglia’s book provides times for both standard and electric pressure cooker. She doesn’t have a formula. The addtional cooking time may be zero or may as much as 50%. Her tables are at the end of her book,and are also available online at hippressurecooking. Her tables are consistent with Jill Nussinow’s observation that necessary adjustments are variable depending on ingredient and release method (and release time).
Recipe sources and manual use terms for the two main options for when to use the pressure release valve – the end of the period of operating pressure, or after waiting for pressure to come down:
|End of OP||Wait|
|Instant Pot Recipe Booklet||Quick Release||Natural|
|Sass, Cooking under Pressure||Quick Release||Naturally|
|ATK, Multicooker Perfection||Quick||Natural|
|Pazzaglia, hip Pressure Cooking||Normal||Natural|
|Schieving, Electric Pressure Cooker Cookbook||Quick||Natural|
|Clark, Dinner in an Instant||Manual||Natural|
There are variations on each option including modified or slow (i.e. incremental, pulsed) quick release and a timed wait with a manual release to be able to open the pot.
Many electric pressure cookers and multi-cookers have sauté functions; some call it “brown” or “browning”. They vary in temperature; usually hot enough to melt fats but not always warm enough to carmelize the food.
Some have a button or setting to engage a “simmer” function. Simmer is a setting in Fagor/Zavor Lux devices that to heat the food at 200 F for up to 30 minutes. Instant Pots can simmer at a slow cooker setting; the slow cooker “high” setting should match the Fagor/Zavor simmer setting. The temperature is an indirect reading – it is what the manufacturer says in the manual and is calibrated to what a sensor outside the pot is reading.
About “Instant Pot” recipe sources:
- An “Instant Pot” pressure recipe should work in any electric pressure cooker or pressure capable multi-cooker; but variations may be needed;
- With adjustments of time, an “Instant Pot” pressure recipe should work in a stovetop or standard pressure cooker;
- Instant Pot has used different terms for preset sauté temperatures in its pressure multi-cookers; and a recipe source may use the term for one model. Other electric pressure cookers and multi-cookers will be different in some ways. A stovetop user has to use the heat setting of the the stove or cooktop. A use will have to see what the food is doing when using any pressure cooker as a skillet;
- Some “Instant Pot” and multi-cooker sources use the pressure and sauté settings almost exclusively, but:
- Some regard the rice function (low pressure and “automatic” time), as a good way to to steam white rice, or using the Instant Pot with additional ingredients like a rice cooker device;
- Some address slow-cooker functions; this is a tricky area;
- Some discuss the other functions that are useful for some cooks.