A flash fryer is a deep frying device commonly used in commercial kitchens, although some home cooks utilize small versions. The flash fryer is designed to heat oil to high temperatures and to keep the temperature stable throughout service so that it can be used continually throughout the night. In some kitchens, the demand on the flash fryer can be quite heavy, and multiple fryers are sometimes installed to ensure consistent preparation of food.
When deep frying at home, many cooks are unable to heat the oil to a sufficient temperature. Deep frying should be done at approximately 365° Fahrenheit (185° Celsius), so that the oil will sear the outside of the object being fried, preventing it from absorbing oil while it fries. This results in crisp, lighter fried foods. As anyone who has eaten oil saturated french fries or fish and chips knows, oily fried food is not pleasant.
However, many oils begin to smoke at approximately 400° Fahrenheit (200° Celsius) and will burn at 500° Fahrenheit (250° Celsius). As a result, when deep frying, the temperature of the oil must be constantly monitored to make sure that it is hot enough to cook well but not heating to a dangerous level. Oil fires are very difficult to put out, and when frying in a high volume of oil, it may bubble over and cause a catastrophic kitchen fire.
A flash fryer is a specially designed device built to address these concerns. A commercial fryer is often quite large, with the ability of handling large volumes of food simultaneously. Versions for home use are often smaller, aimed at more limited kitchen space. In all cases, the fryer uses an enclosed system of heating coils so that the coils are not in direct contact with the oil. Often, a fryer incorporates covers over the vats of oil so that splash back will not cause fire or injury.
The operator fills the oil vats to the recommended depth and turns the flash fryer on. The fryer slowly raises the temperature of the oil until it reaches the correct level, and then works to maintain it. Foods to be fried can be lowered into the flash fryer in baskets for cooking and then set over a draining well so that they do not become soggy.
When using a flash fryer, make sure that it is clean and properly maintained. The oil vats should be emptied and cleaned at the end of service so that the oil does not turn rancid. All electrical connections should be clean and unexposed, as a spark may cause a fire. Do not overfill the fryer or attempt to heat the oil beyond the smoking point. Eye protection, as well as long sleeves and pants, is highly recommended to avoid injury. In a commercial kitchen, sprinklers should be installed, and at home, a fire extinguisher should be kept nearby during deep frying projects.