Pressure Cookers, Their Care and Feeding, or Is That My Dinner Hanging From the Ceiling

No more than a generation or two ago, at the most,to fall apart, causing the entire process to speed up
the words pressure cooker could cause a grown manappreciably.
to suddenly need to run an errand blocks away fromHow It All Works or Welcome to Elementary Physics:
his house. The kids had a burning urge to do theirLet's start at sea level, with a pot that has no lid but
homework, real or imagined, at the far end of thecontains water which boils at 100ºC
house, preferably outside. Poor Mom was deserted to(212ºF). The escaping steam from this pot will
deal with THE CREATURE, which had the terrifyingalso be 100ºC (212ºF). The water will retain
ability to spew forth chunks and splats of dinner onthe 100ºC reading,irregardless of how much heat
every conceivable surface of the kitchen, from theis directed at it. But, the pressure inside the pot can rise
pristine white ceiling to the sparkling linoleum floor.precipitously if the water evaporation is trapped by a
Cooking dinner "under pressure" had turned intowell-sealed lid.
hand-to-cooker combat with mops, rags, and spongesThe rising pressure, as well as the temperature of the
against dripping walls and puddles from stem to sternsteam and water inside the pressure cooker, will rise
of the kitchen. Sigh...What an enticing prospect!above the normal 100ºC boiling point
But lo and behold! The pressure cookers of the earlytemperature.
21st century present no injury to life or limb and areFood inside the cooker cooks extremely rapidly,
easy to use, too. These modern-day marvels areanywhere from 3 to 4 times faster, due to the steam
thought to be descended from Denis Papin's jewel ofpressure. The steam causes the intense intermingling
engineering. Papin, a French physicist living in London,of flavors, as well as giving the pressure-cooked food
designed the prototype of today's pressure cooker,enhanced moistness and succulence. Many more
which was alternately called a pressure resister,vitamins and nutrients remain behind than with
digester or digestor, or retort while serving as aconventionally boiled food. And remember, the higher
laboratory assistant to Robert Boyle, a chemist bestthe pressure, the more quickly (up to 70%) the food
remembered for Boyle's Law, a physical law whichwill cook, giving you time to enjoy your family and
proposed that the pressure and volume of a gas arefriends.
dependent upon one another.Take care not to add different foods all at once. They
Papin demonstrated his device by cooking turkeywill turn to mush if steamed too long. Put in
bones in it before the Royal Society in 1679. Thislonger-cooking foods first, release the pressure, and
pressure digester included a very tight lid on a vessel;then add the final shorter-cooking foods last.
provided with sufficient pressure, it enabled theWatch the pressure on your cooker. Have no qualms
contents of the vessel to be raised to a very highabout lowering the heat from the stove; this needs to
temperature. It was given a safety valve as protectionbe done immediately so that the pressure will reduce
against an exorbitant rise in the pressure, thus releasingitself.
the excessive steam.When the cooker reaches the full predetermined
Let's jump down the time some two hundred and fiftypressure, it is time to start cooking times. Until you learn
years to the first modern use of the pressure cooker.to predict how slowly or rapidly your pressure cooker
The 1939 New York World's Fair was the showcasefunctions, it is best to estimate cooking times on the
for the first commercially made aluminum pressurelow side.
cooker, made by the National Pressure CookerHigh altitudes mean increased cooking times. There is
Company, later to become the Presto Company,no need to make any adjustments for elevations from
which today is known internationally. The Baby Boomsea level to 2000 ft. but for every 1000 ft. beyond the
in the late 1940s was a significant force in the2000 ft. base, cooking time should be increased by 5%.
manufacture of the new-style pressure cookers.Simply the mere thought of an old pressure cooker
Unfortunately, many of these cookers had hiddenshooting off its mouth (so to speak) was cause for
flaws contributing to the high rate of explosivethe cold sweats. Rejoice! Today's pressure cookers
accidents and general mistrust of them.are built for safety. Until the pressure is released from
By now, "modern" pressure cookers were appearing inthe pot, it is virtually impossible to open a modern
homes all across America. In the beginning, there wascooker.
an issue of mistrust (and justifiably so). However, asThere are two choices by which to release the steam:
we go trippingly along the timeline, we find ourselvesthe Natural Release method and the Quick Release
over the boundary into the 21st century wheremethod. The Natural Release is extremely simple.
pressure cookers are items of sheer delight in theRemove the pot from the heat source and allow the
ease of use. No more spaghetti à la spaghetti...pressure to slowly release itself while the pot's
Basically, the modern pressure cooker is a kitchen pottemperature decreases. This method of release
with an elaborate lid making a tight, complete seal soenables tough cuts of meat and such to remain in a
that the explosions of yore are not even a conditionsteam chamber which helps to tenderize the food.
that might present itself to an absentminded chef. InThe other method, the Quick Release, uses an
order for the pressure to work, a sealed pot or vessel,automatic release. It is not a problem if your pressure
adjusted to a predetermined pressure will not allowcooker does not have an automatic release. Merely
liquids or steam to spurt forth from the cooker.move the pot from the stove to the sink. Turn the cold
The boiling point of water will increase as the pressurewater tap on the pressure cooker, allowing the
in the cooker climbs higher, in search of thedifference in temperatures to bring about a quick
precalculated pressure. Because of this increase, therelease of pressure.
escalating pressure causes the liquid to reach aPay attention to the gasket and valves. The gasket
temperature in excess of 100ºC (212ºF)must remain flexible to do its job properly. Be sure to
before it boils. In 1917, the USDA elected to make thekeep food debris and residue from lodging in the
internal pressure setting 15 psi (pounds per squarevalves. Most importantly, do not immerse the lid in
inch), where upon water will boil at 125ºCwater and use dishwashing liquid to hand wash the pot.
(257ºF). As the temperature rises, the moreTake good care of your pressure cooker and it will
quickly the food will cook. The fibers in the food begintake good care of you.