Pressure cooking

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Cooking pressure is a food cooking process, using water or other cooking fluid, in a closed vessel known as a pressure cooker.

Pressure is made by boiling liquid, such as water or broth, in a pressurized pot covered. The trapped steam increases internal pressure and allows the temperature to rise. After use, the pressure is slowly released so that the ship can be safely opened.

Cooking pressure can be used for rapid simulation of long braising effects. Almost any food that can be cooked in steam or water-based liquids can be cooked in a pressure cooker.

Video Pressure cooking

History

In 1679, the French physicist Denis Papin, better known for his studies of steam, invented the steam digester in an attempt to reduce the cooking time of food. The impermeable cooker uses vapor pressure to raise the boiling point of water, thus cooking the food faster. In 1681, Papin presented his findings to the Royal Society of London, but members of the Society treated his findings as scientific research. They gave him permission to become a member of the Society after that.

In 1864, Georg Gutbrod of Stuttgart began producing pressure cookers made from cast iron cans.

In 1918, Spain granted a patent for pressure cooker to Jose Alix MartÃÆ'nez of Zaragoza. MartÃÆ'nez named it olla exprÃÆ' Â © s , literally "cook cooking pot", with the patent number 71143 in BoletÃÆ'n Oficial de la Propiedad Industrial . In 1924, the first pressure cookbook cookbook was published, written by José Alix and titled "360 fÃÆ'³rmulas de cocina The guisar con la 'olla expres'", or 360 recipes for cooking with pressure cooker .

In 1938, Alfred Vischer presented his invention, Flex-Seal Speed ​​Cooker , in New York City. Vischer's pressure cooker was first designed for home use, and its success led to competition among American and European producers. At the 1939 New York World Exhibition, the National Pressure Cooking Company , later renamed National Presto Industries , introduced its own pressure cooker.

First generation

Also known as an "old-style pressure cooker", it operates with a modified valve or "jiggler", which releases pressure during operation. Some people find it hard because the valve vibrates when excess steam is released. Pressure cookers usually offer only one level of pressure. Some newer pressure cookers allow the operator to change the weight of the valve, thereby changing the pressure.

Currently, most pressure cookers, including those manufactured by Presto are variations on the first-generation stoves, with the addition of new safety features such as a mechanism that prevents the stove from being opened until it is fully suppressed.

Second generation

It operates with a spring valve that is often hidden from view in the possession mechanism. This generation is characterized by two or more pressure settings. Some of these pressure cookers do not release any steam during operation (non-venting) and instead use up indicators with signs to indicate pressure levels. This only releases steam when the pot is opened, or as a precaution if the heat source is not reduced sufficiently when the pan reaches the required cooking pressure. Others use dial that the operator can forward with a few clicks (which change the spring tension) to change the pressure settings or release the pressure; this releases steam during operation (ventilation).

Third Generation "Electric pressure cooker"

After the stove top cooker stove, in 1991 came the electric pressure stove, called the "third generation" pressure cooker.

This includes a source of electrical heat that is automatically set to maintain operating pressure. They also include a spring valve (as described above). Pressure cookers of this type can not be opened by cold water release method and must be operated with caution when releasing steam through the valve, especially when cooking foamy food and liquids (lentils, nuts, seeds, milk, sauces, etc.)

The electric pressure pressure integrates the timer. Depending on the ability of the cooking control, there are three generations of electric pressure cooker:

• First generation electricity, with a mechanical timer. No cooking skills are pending.
• Second Generation Electricity, with digital controller. Pending cooking becomes possible and the controller shows the countdown timer when work pressure is reached.
• Third Generation Electricity, with intelligent programming, which includes cooking times and pre-arranged settings based on the intensity of heating, temperature, pressure, and duration.

Some multi-function cookers (multicookers): pressure cooker, stir-fry/browning, slow cooker, rice cooker, yogurt maker, steamer and warm pot that can also be used to warm cooked food.

Maps Pressure cooking

Theory

In a regular cooking tub, without pressure, the boiling point of water is 100 ° C (212 ° F) at standard pressure; The food temperature is limited by the boiling point of water because excess heat causes the boiling water to evaporate into steam. In a closed pressurized pot, the boiling point of water increases as the pressure rises, producing very hot water. At a pressure of 1 bar or about 15 psi (pounds per square inch) above the existing atmospheric pressure, the water in the pressure cooker will reach a temperature of 121 ° C (250 ° F). The water boiling temperature (and water-based liquids) is determined by atmospheric ambient pressure. Pressure cookers always need fluids to cook food under pressure. In the pressure cooker, once the water (liquid) boils and the vapor is trapped, the pressure from the vapor increases and pushes on the liquid, which increases its boiling temperature. The heat applied to liquids by heat sources continues to create more vapor pressure, and increases the temperature of the liquid. Both the liquid and the steam are at the same temperature. Once the selected pressure level is reached, the pressure regulator on the lid releases excess steam, and heat can be lowered to maintain pressure and save energy, as the pressure will not increase again.

As a general rule, increasing the temperature of a chemical reaction by 10 degrees doubles the rate of reaction. So pressure cooker, which can maintain the internal temperature of 120 Ã, Â ° C (248Ã, Â ° F), can finish cooking four times faster than regular boiling.

Due to the much higher heat capacity, steam and fluid transfer heat faster than air. For example, hot air in an oven at 200 ° C (392 ° F) will not burn your skin immediately, but steam from the boil boil at 100 ° C (212 ° F) will blister the skin almost instantly and noticeably more heat, although the steam (and water) in the kettle is at a lower temperature than the air in the hot oven. So the internal temperature of the material in the pressure cooker will rise to the desired value much faster than if it were in the oven.

Some recipes, which require browning to develop flavor during roasting or frying, require higher temperatures than those in the pressure cooker. Pre-frying materials in an open pressure cooker are sometimes recommended before the actual cooking process begins.

High altitudes

Pressure cookers can be used to compensate for low atmospheric pressure at high altitudes. The boiling point of water drops by about 1 ° C per every 294 meters (1 ° F per 540 feet (160 m) elevation), causing the boiling point of water to be well below 100 ° C (212 ° F) under pressure standard. Without using a pressure cooker, boiled food may be underdone, as described in Charles Darwin [The Voyage of the Beagle] (chapter XV, March 20, 1835):

After crossing the Peuquenes [Piuquenes], we descended into a mountain country, intermediate between two main ranges, and then took our place for the night. We are now in the Mendoza republic. The altitude may not be below 11,000 feet (3,400 m) [...]. In the place where we sleep, water must be boiled, from reduced atmospheric pressure, to a lower temperature than in a lesser state; case becomes the opposite of Papin digester. Therefore potatoes, after remaining a few hours in boiling water, are almost as hard as before. The pot was burned in the fire all night, and the next morning boiled again, but the potatoes had not been cooked.

At higher altitudes, the boiling point of the liquid in the pressure cooker will be slightly lower than at sea level. When cooking pressure is at high altitude, cooking time needs to be increased by about 5% for every 300 m (980 ft) above 610 m (2,000 ft). The absolute pressure in the pressure cooker will always be lower at higher altitudes, because the differential pressure remains the same (if one travels high enough, the pressure inside the stove will drop below sea level pressure). Since weight is one of the main problems, a mountain pressure stove may be designed to operate at a much lower differential pressure than an ordinary unit so that a thinner and lighter construction can be used. Generally, the goal is to raise the cooking temperature sufficient to cook and save fuel by reducing the heat lost through boiling.

Light pressure stove as small as 1.5 liters (0.40 US gal) weighing 1.28 kilograms (2.8 pounds) is available for mountain climbers. The Sherpa often use pressure cookers at base camp.

Health benefits

Some food poison can be reduced by cooking pressure. A Korean study of aflatoxin in rice (associated with Aspergillus fungus) shows that cooking pressure can reduce aflatoxin concentrations by up to 12-22% of the amount in unboiled rice. Pressure cookers are not guaranteed to destroy all harmful microorganisms in food, especially when used for a short time.

Food is not suitable for cooking pressure

Some foods are not recommended for cooking pressure. Foods such as noodles, pasta, cranberries, cereals, and oatmeal can inflate too much, froth, and grunt, which can block the vents of the vapor.

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Design

Capacity

Pressure cookers are available in different capacities for cooking in larger or smaller quantities, with a common 6 liter capacity. The maximum capacity of food is less than the advertised capacity because the pressure cooker can only be charged up to 2/3 full, depending on the ingredients and fluids (see Security features section).

Pan

• Body pan metal
• Pot holders, usually each on the opposite end, to bring the stove with both hands

Close

• Close the handle, usually with a lock or latch lock device that "clicks" closed and prevents wipe while cooking
• Gaskets (also known as "sealing rings") that seal airtight cooker
• Ventilation vapor with the above pressure regulator (either heavy or spring device) that maintains the pressure level in the pan
• The pressure indicator pin, to indicate the presence or absence of any pressure, however small
• Security devices on the lid (usually excess pressure valves and/or excess temperatures)
• Pressure gauge (usually no but includes some more expensive models)

Accessories

• The steamer basket
• Triple marker to store the steamer basket above the liquid
• Metal barrier, to separate different foods in a steamer basket for example. vegetables

Pressure cookers are usually made of aluminum (aluminum) or stainless steel. The aluminum pressure stove can be stamped, polished, or anodized, but they are not suitable for dishwashers. They are cheaper, but reactive aluminum for acidic foods, whose flavors change in reaction, and are less durable than stainless steel pressure pans.

High-quality stainless steel pressurized stoves are made with heavy but three-layer, or copper (heat spread) bottoms for uniform heating because stainless steels have lower thermal conductivity. Most modern stainless steel cookers are safe dishwashers, although some manufacturers may recommend washing by hand. Some pressure cookers have non-stick interior.

Gasket

A gasket or sealing ring, made of rubber or silicon, forms a gas-resistant seal that does not allow air or vapor to exit between the lid and the pan. Usually, the only way steam can pass is through the regulator on the lid when the stove is pressed. If the regulator becomes obstructed, the safety valve provides a backup escape route for steam.

To close the gasket there are several main methods used. Each determines the pressure cooker design:

• The twist-on design has a slot on an attractive cap with flanges on the body, similar to a cap on a glass bottle, which works by placing a lid on a saucepan and rotating about 30 Â ° to lock it. A common modern design, it has easily implemented a locking feature that prevents the removal of the cap when under pressure.
• The middle screw design has a rod placed above the lid and screws that are tightened down to hold the cover. Despite the older design, it is still manufactured due to its ease of construction and simplicity.
• The bolt-down design has flanges on the lid and the body for bolts is skipped, and usually uses wingnuts that are body-dependent and never completely removed from the stove; This sealing design is usually used for larger units such as canning retort and autoclave. It's easy to produce, and can be sealed with a simple and inexpensive gasket.
• Internally-mounted sealed designs using an oval cover placed inside and pressed out; the user inserts the lid at an angle, then rotates the lid to align it with the pan opening above because the lid is larger than the opening. The spring setting holds the cover in place until pressure is formed and holds the lid firmly against the body, preventing appointment until pressure is released.

Because of the strength that the pressure cooker must bear, they are usually heavier than conventional pots of the same size.

Security features

The initial pressure cooker equipped with only the main safety valve risks the explosion of the food blocking the release valve. In modern pressurized stoves, food residues that block ventilation of steam or dry boiling liquid will trigger additional safety devices. Modern pressure cookers sold from reputable manufacturers have enough security features to prevent the pressure cooker itself from exploding. When excess pressure is released by the safety mechanism, the flakes of cooked food can also be removed with steam, which is hard and strong. This can be avoided if the pressure cooker is cleaned and maintained regularly according to the manufacturer's instructions and is never filled with food and/or liquid.

Modern pressure cookers typically have two or three excess safety valves and additional safety features, such as an interlock cover that prevents the user from opening the lid when internal pressure exceeds atmospheric pressure, preventing accidents from sudden release of hot liquids, steam and food.. If the security mechanism is not installed properly, the stove will not press its contents. Pressure cooker should be operated only after reading the user manual, to ensure correct usage. Harmful pressure cooker failure: large amounts of steam and boiling hot water will be forcibly expelled and if the lid separates it can be pushed with great force. Some cookers with internally mounted lids can be very dangerous on failure because the lid is tighter with increased pressure, preventing the lid from deformation and ventilation around the edges. Because these hazard pressure cookers are generally over-engineered in terms of safety and some countries even have regulations to prevent the sale of non-compliant stoves.

For a first-generation pressure cooker with a weighted or jiggler valve, the main safety valve or regulator is usually a weighted stopper, commonly called a "rocker" or "weight of the vent." This weighted plug is removed by the vapor pressure, allowing excess pressure to be removed. There is a pressure release mechanism that releases pressure rapidly if the primary pressure release mechanism fails (eg, food jams of the steam exhaust). One such method is a hole in the lid that is blocked by a low melting point alloy plug and the other is a rubber grommet with metal inserts in the middle. At sufficiently high pressures, the grommets will be distorted and the insert will come out of the mounting hole to release the pressure. If the pressure continues to rise, the grommet itself will explode to release the pressure. This safety tool usually requires replacement when activated by excess pressure. The newer pressure cooker may have a self-adjustable spring device, mounted on the lid, which releases excess pressure.

At second generation pressure cookers, the common security feature is a gasket, which expands to release excessive pressure down between the lid and the pan. The release of this excess pressure is very strong and sufficient to extinguish the flame of the gas stove.

Pressure cookers sold in the European Union (EU) must comply with the Pressure Equipment Directive.

Maximum content level

The recommended maximum level of food/liquid avoids blockage of the steam valve or develops excess pressure: two thirds full of solids, half full for liquids and foamy food and froth (eg, rice, pasta); adding a tablespoon of cooking oil minimizes foaming, and is no more than a third full for pulses (eg, lentils).

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Operation

Liquid

Cooking pressure always requires fluids. Cooking pressure can not be used for cooking methods that produce little steam such as grilling, frying pan, or deep frying. thick sauce does not contain enough liquid to evaporate and create pressure, so they usually burn to the bottom of the interior pressure cooker after prolonged heating. The sauce should be thickened after cooking pressure.

Bringing pressure (stove top pressure cooker)

Food is placed in a pressure cooker with a little water or other liquid like broth. Food is cooked in liquid or over liquid for steaming; the last method prevents the flavor transfer from the liquid. The lid is closed, the pressure setting is selected and the pressure cooker is placed on the stove at the highest heat (less than high for induction cooking to allow air to be disposed). After the stove reaches full pressure, heat is lowered to maintain pressure; the recipe time starts at this point. Recipes for food using infiltration agents such as steamed pudding call for soft pre-steamed, unpressured, to activate the raising agent before cooking and achieve light, fine texture.

It takes a few minutes for the pressure cooker to reach the selected pressure level. This can take about 10 minutes or more depending on: amount of food, food temperature (cold or frozen food delay pressure), amount of liquid, heat source strength and pressure cooker size.

A common mistake is that the user starts a time when the color pop-up indicator rises, which occurs when there is a slight increase in pressure, instead of waiting for the stove to reach the selected pressure level. The typical pop-up indicator only indicates that the stove has internal pressure, which can not reliably indicate that the stove has reached the selected pressure. These pop-up indicators often act as interlocks, preventing open caps while there is internal pressure. Manufacturers can use their own terminology for it, like calling it a "locking indicator."

As the internal temperature rises, the pressure also rises until it reaches the design gauge pressure. The prescription time begins when the selected pressure is reached. With the design of the first generation, the weight of the pressure regulator starts to float above its nozzle, allowing excess steam to exit. In the second-generation pressure cooker, the release valve then opens, releasing the vapor to prevent further rising pressure or the stem rises with a marker to indicate the pressure level, without constantly removing the vapor. At this stage, the heat source is reduced to the lowest heat possible while still maintaining the pressure, since extra heat wastes energy and increases fluid loss.

Air Removal

Before the pressure cooker cap is tightly closed, the internal air must be replaced mostly by steam. The steam has a specific heat much higher than air, and the presence of steam rather than air inside the pressure cooker is how it is able to transfer sufficient heat to parts of food that are not immersed in liquids, such as roast beef. If the lid is sealed before enough air has been removed, not enough heat can be transferred to the food, and the food may be undercooked; The presence of air will make cooking food more like in an oven than a pressure cooker. To remove air, the steam is removed for several minutes to replace the air volume inside the stove. This is why the pressure cooker takes about 10 minutes to reach the pressure. For heavy pressure cookers, the weight is placed over the steam ventilation pipe while steam is being emitted to ensure the air inside has passed. New-generation pressures cooker, which has no weight, automatically ejects air from within for a few minutes before the colored pop-up indicator pin rises to seal airtight; pressure is then built on the stove which is now airtight. If the pressure cooker is hot or the stovetop pressure stove is placed on a very strong heat source, such as induction at too high a setting, the lid can seal airtight too quickly before the air inside is removed. In this situation, a slightly lower heat setting can be used to allow boiling water slower to vent air.

Food container

Small containers such as plastic pudding containers may be used in pressure cookers, if the container (and any cover used) can withstand temperatures of 130 ° C (266 ° F) and is not placed directly at the base of the interior. The container can be used to cook food that is susceptible to burning at the base of pressure cooker. A container lid may be used if the lid allows some steam to come into contact with the food and the lid is seated properly; Examples are foil or fat-resistant paper, folded in the middle and securely tied with a rope. Containers that are cracked or have sustained damage are not appropriate. Cooking time is longer when using a closed container because the food is not in direct contact with the steam. Since non-metallic containers are worse heat conductors, the type of container material expressed in the recipe can not be replaced without affecting the result. For example, if the recipe time is calculated using stainless steel containers and plastic containers used instead, the recipe will become undercooked, unless cooking time increases. Containers with thick sides, for example, glass containers or oven-resistant ceramics, which are slower to heat, will add about 10 minutes to the cooking time. Fluids can be added in a container when the pressure of cooking food is like rice, which needs to absorb the liquid to cook properly.

Pre-frying material

The flavors of some foods, such as meat and onions, can be improved by slowly cooking with some pre-heating cooking oil, butter or other fat in an open pressurized pot over medium heat for furnace models (unless the manufacturer recommends this) before cooking pressure, while avoiding overheating of the pressure cooker does not heat the empty cooker with lids and gasket in place to avoid damage. The electric pressure pressure usually has a "stir-fry" or "brown" option for frying the ingredients. Pressure cooker should cool briefly before adding liquid; if not, some of the liquid will evaporate instantaneously, it may leave insufficient fluid for the whole cooking time of pressure; if the pot deglazing, more fluid may need to be added.

Release methods of pressure

After cooking, there are three ways to release the pressure, either sooner or later, before the lid can be opened. Recipe for a pressure cooking country that requires a method of discharge at the end of cooking time for the right results. Failure to follow recommendations may lead to undercooked or overcooked foods.

To avoid over-opening the pressure cooker when cooking different vegetables with varying cooking times, vegetables that take longer to cook can be cut into small pieces and cooked vegetables faster can be cut into thicker pieces.

Manual, normal, regular, or automatic release

This method is sometimes called quick release, not to be confused with cold water release (mentioned below). This involves the rapid discharge of the vapor by gradually lifting (or removing) the valve, pressing a button, or rotating a button. It is best suited to interrupt cooking to add cooked food faster than the one already in the stove. For example, since meat takes longer to cook than vegetables, it is necessary to add vegetables for cooking later so it will ripen only for the last few minutes. In contrast to the cold water release method, this method of release does not cool the pressure cooker. Giving away the steam carefully avoids the risk of hot water splashing due to the rapid release of hot steam. This method of release is unsuitable for foam and foam foods when cooking; the heat contents may be gushed out due to the pressure released from the steam vents. This release method takes about two minutes to release the pressure before the lid can be opened.

Natural releases

The natural release method allows the pressure to descend slowly; this is achieved by releasing the pressure cooker from the heat source and allowing the pressure to degrade without action. It takes about 10 to 15 minutes (maybe longer) for the pressure to disappear before the cover can be opened. In many pressure cookers, the colored indicator pins will fall when the pressure is gone. This natural release method is recommended for foamy and frothy foods during cooking, such as rice, legumes, or recipes with bubble agents such as steamed pudding. The texture and softness of the meat cooked in the pressure cooker can be improved by using natural release methods. The natural release method finishes cooking a meal or a recipe that has a longer cooking time because the inside of the pressure cooker remains hot. This method is not recommended for foods that require a very short cooking time, otherwise the food will be overcooked.

Rapid release of cold water

This method is the fastest way to release pressure with a portable pressure cooker, but it can be dangerous if done incorrectly. It is therefore safer to release pressure by following other methods. The manufacturer's instruction manual may suggest cold water release or require it to be done differently.

The cold water release method involves the use of slow-running cold tap water, over the edge of the pressed pressure cap, being careful to avoid steam ventilation or other valves or outlets and never to immerse a pressure cooker underwater, otherwise steam can be removed from the water. under the lid, which may cause a boiling injury to the user; also the pressure cooker cap can be permanently damaged by the internal vacuum if water is sucked into the pressure cooker, as the incoming water obstructs the airflow.

The release of cold water is best suited for food with short cooking times. It takes about 20 seconds for the stove to cool enough to lower the pressure so it can be safely opened. This method is not suitable for electric pressure cookers, because they are not "immersible."

Cold water release methods are not recommended when cooking pulses such as red kidney beans, since sudden pressure release can cause peanuts to break apart.

Pressure settings

Most pressure cookers have a cooking pressure setting (operation) between 0.8-1 bar (11.6-15 psi) (gauge) so that the pressure cooker operates at 1.8 to 2.0 bar (absolute). The cooking pressure of the standard 15 psi gauge was determined by the United States Department of Agriculture in 1917. At this pressure, water boiled at 121 ° C (250 ° F) (described in the water vapor pressure article).

Higher temperatures cause food to be cooked faster; cooking time can usually be reduced by up to one-third of the time for conventional cooking methods. The actual cooking time also depends on the pressure release method used after the time (see Pressure release method for details) and the thickness and density of the food, since thicker (and denser) foods take longer to cook. The meat joints and some other foods such as sponge pudding and Christmas pudding are usually arranged according to the weight. Frozen foods require extra cooking time to allow thawing.

When cooking pressure at 1 bar/15 psi (meter), the estimated cooking time is one minute for grated cabbage, seven minutes for boiled potatoes (if cut small, not diced) and three minutes for fresh green beans. If the pressure is released naturally after the time (see Pressure release method for details), cooking time is even shorter. Food is cooked faster when cut into small pieces.

Some recipes may require cooking lower than 1 bar/15 psi (gauge) for example. fresh vegetables, as these can easily overcook. Many pressure cookers have 2 or more pressure or weight settings to choose from.

Some pressure cookers have a maximum pressure lower or higher than 1 bar/15 psi (gauge) or can be adapted to different pressures for some recipes; cooking time will increase or decrease. This is usually done by having different regulatory weights or different pressure settings. If the recipe is designed for higher pressure and pressure cooker does not reach that pressure, cooking time can be increased slightly to compensate. The electric pressure cooker operates at a lower pressure than the stove pressure cooker.

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Advantages and disadvantages

Benefits

Food is cooked faster by cooking pressure compared to other methods (except for small quantities in a microwave oven). Cooking pressure requires far less water than conventional boiling, so the food can be more quickly prepared. Less energy is needed than boiling, steaming, or cooking with an oven. Because less water or liquids must be heated, the food reaches its cooking temperature faster. Using more fluid than required energy waste because it takes longer to heat up; Liquid quantity is expressed in the recipe. Pressure cookers can use less liquid than the amount required to boil or steam in a regular pan. No need to dip the food into the water. The minimum amount of water or liquid used in the prescription to keep the pressure cooker filled with steam is sufficient. Therefore, vitamins and minerals are not washed (dissolved) by water, as would happen if food is boiled in large amounts of water. Because of shorter cooking times, vitamins are preserved relatively well during cooking pressure.

Some foods can be cooked together in pressure cooker, either for the same amount of time or added later for different times. Manufacturers provide a steamer basket to allow more food to be cooked together in a pressure cooker.

The food is cooked faster in a pressure cooker because at higher pressure (15 psi), the boiling point of water rises from 212 ° F to 250 ° F. More importantly, the steam temperature also rises to 250 ° F, at which point called super hot steam. This super-hot vapor (ie vapor under pressure) is capable of sending its heat energy to the food at a dramatically increasing rate. The higher water temperature has little effect on cooking time, it is the steam that is doing the work. One can consider steam locomotive. The large tank of boiling water (boiler) is only a source of steam. It is the steam itself that does the work of moving the piston and moving the locomotive forward. Not only is this vapor energy transmitted rapidly to food, it is also transmitted rapidly to any existing micro-organism, easily killing even the lethal species that can survive at a boiling point. Because of this enhanced germicidal ability, pressure cooker can be used as an effective sterilizer for jams, baby glass bottles, or for water while camping. In fact, autoclaves, which are used in hospitals to sterilize surgical instruments, are in fact just a more precise and technical version of the usual pressure cooker.

Losses

Pressure cookers are much more expensive than conventional sauces of the same size. Additional gaskets (insulation rings) require special care when cleaning (for example, not washed with kitchen knives), unlike standard cover for pans. Food waste should be cleaned from the gasket whenever it is used. The gasket/sealing ring needs to be replaced with new ones about once a year (or faster if broken eg small splits). A very dry gasket can make it difficult or impossible to close the lid. Polishing gaskets with a little bit of vegetable oil reduces this problem (using too much vegetable oil can make the gaskets swell and prevent it sealed properly). Gaskets that have lost their flexibility make the stove more difficult because the steam can get out before enough pressure is produced to provide an adequate seal; this is usually a sign that the gasket should be replaced with a new one. Oiling gasket with vegetable oil can alleviate temporary problems, but new packing is often necessary. The pressure cooker manufacturer sells replacement gaskets and recommends replacement periodically, for example every year. If the pressure cooker is not used for a long time, the gasket and other rubber or silicone components will dry out and may need to be replaced.

To check the food, pressure cooker needs to be opened, which stops the cooking process. With a conventional pot, this can be done in seconds by checking the food visually. As a result, accurate timing is essential for the prescription, e.g. with an audible timer.

The weight increase from conventional pressure cookers makes them unsuitable for applications where heavy savings are a priority, such as camping. However, small and light pressure stoves are available for mountaineers (see Use at high altitudes) .

The minimum amount of fluid needed to create and maintain pressure, as shown in the manufacturer's manual instructions. More fluid is required for longer cooking times. This is not desirable for foods that require less fluid, but recipes and books for pressure cookers consider this.

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Use as weapon

This tool has been adapted as a type of rough bomb, which has been used in terrorist attacks.

• 2006 Mumbai train bomb
• Stockholm 2010 bombing (failed to explode)
• the 2010 Times Times car bombing attempt (failed to explode)
• Boston Marathon bombing 2013
• New York and New Jersey 2016 freeze

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Variant

An autoclave is a type of pressure cooker used by laboratories and hospitals to sterilize equipment.

Large pressure cookers are often called canners in the United States, because of their capacity to hold the jars used in canning. Pressure canners are specially designed for home canning, whereas the usual pressure cooker is not recommended for canning because of the risk of botulism poisoning, because pressure caners hold heat and pressure longer than ordinary pressure pans; these factors are an important part of the total processing time required to destroy harmful microbes.

The pressure pitcher is used for deep-fat frying under pressure, because the regular pressure stove is not suitable for frying pressure.

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See also

• List of cooking utensils

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References

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External links

• Cooking Cooking Pressure

Source of the article : Wikipedia