Deep fat frying is a cooking method that can be used to cook foods such as fried chicken, French fries, and potato chips. The process involves submerging a food in extremely hot oil until it reaches a safe minimum internal temperature. When the food is deep-fried properly, it will be hot and crispy on the outside and cooked safely in the center. Deep frying is very fast and, when performed properly, destroys bacteria.

Deep frying oil can reach temperatures of over 400 °F. When cooking at this temperature, extreme safety measures should be taken to prevent burning oneself or starting a fire. Like other oils, cooking oil is a highly flammable liquid. To prevent flare-ups and house fires, avoid letting oil contact direct flames. Because of this hazard, it is highly recommended to have a kitchen fire extinguisher available when deep-frying.

Water is a very dangerous liquid when deep frying. When water encounters very hot oil (about 350 °F) water vaporizes instantaneously turning into super heated steam. It expands quickly, which can cause oil to splatter and risk bodily injury. Do not let water get into the hot fat or use water to cool, or clean the appliance while food is deep-frying.

In the event of a grease fire, never use water to put out the fire. Using water can cause flaming oil to splatter and spread. A kitchen fire extinguisher or covering the fryer with a metal lid is the best way to put out a grease fire. Call 911 immediately if a grease fire occurs.

• If you have a deep fryer, read the directions in the owner's manual before using the appliance.
• If you do not own a fryer, use a deep, heavy skillet to fry. However avoid using cast iron as it breaks down oil faster than other metals.
• Purchase and prepare all of the ingredients you plan to deep fry.
• Have a kitchen fire extinguisher nearby.
• Before you fill the deep fat fryer with oil, make sure the fryer is turned off, away from water sources and wiped dry.

If using a deep fryer, do not overcrowd the frying basket, which can cause undercooking, uneven cooking, and overflowing of the oil. To prevent splattering oil or burning yourself, do not touch the frying basket or add food while the basket is submerged in oil. It is important never to leave your fryer unattended. Because frying is a very fast cooking process, food can blacken, burn, and become a potential fire hazard if cooked only a few minutes too long.

If you are frying in a skillet, use a slotted spoon or tongs to take the food out of the oil when you think it is done. Never use plastic when deep-frying as some plastic can easily melt in the hot oil. If using a deep fryer, remove the basket. Do not test the internal temperature of the food while it is submerged in the hot oil; this will lead to an inaccurate temperature reading.

Place the food on a plate covered with paper toweling. Use a clean food thermometer to check the internal temperature of meat, poultry, or seafood (see table below).

If the internal temperature is below the minimum safe internal temperature, submerge the food again. Although the food may look dry after a few minutes it can still be very hot. Take extreme care when handling or eating deep fried foods.

When you have finished cooking all of your food, turn off your fryer and unplug it to allow the oil to cool. (If using a skillet, take it off the heat.) When you are ready to clean your fryer, make sure the fryer is completely cooled (wait approximately 2 hours).

If you are planning to reuse the oil, strain it through a cheese cloth or sieve. Store the used oil in a sealed and light-proof container for up to 3 months. For best quality, refrigerate used frying oil that you want to use again.

If the oil is clouded or if the oil starts to foam or has a foul odor, taste, or smell, discard it. The safest way to dispose of oil is by pouring it into a sealable metal container such as a coffee can, or gallon milk jug, and then throw the oil-filled container in the trash. Used cooking oil can also be recycled in some areas. If there is a recycle drop-off point in your area, check it to see if they will accept your oil so it could be used to make biodiesel fuel or soap.

Do not pour oil down the sink. Oil will cool with water in the drain and congeal causing backups in your sink, septic system, or public sewer system.

Refrigerate leftovers within 2 hours of frying (1 hour if the temperature is above 90 °F). Cooked food left over 2 hours at room temperature can cause rapid bacteria growth and make the food unsafe to eat.