Extend your fry oil life, Improve your fried Food, with significant savings, Slowing the Oxidation Process

Magnetic Poles

Oxidation Kills the Oil

Fried Food is the responsibility of the Chef or Cook. Testing or eating a sample is a most important practice. If the fried food taste poorly or smells bad (rancid), the fry oil must be replaced.

Oxidation is the process that reduces fry oil life. Scientifically fry oil oxidation is caused by the loss of electrons. Electrons have a negative charge. Food has a negative charge. Similar to a magnet, like poles repel. As the level of oxidation (bad) increases with the fry oil the more oil will penetrate into the fried food. The oxidation process can be reduced, improving your overall fried food quality, consistency & fry oil longevity.

Carbon, Air, Salt, Heat, Filtering, Light, Oxidation, & Water

An operation can create high-quality fried foods consistently better than the competition keeping costs down. Restaurant management will remember the term "CASHFLOW" in relationship to fry oil oxidation. Following the "CASHFLOW" principles will near double your fry oil life & your restaurant will serve tastier, juicier, crisper fried product while maximizing profits. The fried food will remain hotter, for longer, beneath the golden coating. This result is most important with todays increase of delivered and/or take-out food. No one wants soggy fried food when they arrive home.


How clean is your frying equipment? Reducing carbon is generally filtering the oil, skimming the food particles, & keeping the fryer clean. Excess coating in fried foods can also cause foaming on the oil surface. Weekly fryer boil-outs will keep your deep-fryers easy to claen. Hey lazy butt .... Clean the oil tank before refilling with fresh oil.


Life without air is difficult. To minimize oxidation, don’t splash or pour food into the fryer from a great distance. Splashing can lead to air getting pushed into the frying oil. During down or slow frying periods (between lunch & dinner) make sure to cover the fryers to further protect the oil from oxidation. Most fryer covers are on Amazon.com or sold through restaurant supply stores.

Salt or Spice

Never Salt or spice over the deep-fryer. Salt acts as a catalyst, accelerates oxidation, causing the oil to breakdown. Never refry fried food for the same reason. Take the fries or fried food out of the fryer .... then add salt & seasoning.

Heat or Temperature

Always fry at 350F or below. A common mistake is to fry at 375F. The thought is to speed up the frying times. The actual result is an uncooked center (raw) & burnt outside coating. Nothing like under-cooked fried food. As oil deteriotes (oxidates), heat transfer (viscocity) is lowered. Remember the Maillard Reaction on browning food. The golden-brown color of French fries begins at a minumum temperature of 325F. To be clear, the browning of all cooked foods (fryer or oven) starts at 325F.

Set a scheduled time for turning off/down the fryers. Decrease your fryer temperature to 285F during breaks in frying times (between meals). When the frying restarts it will not take too long to get the fryers back to the correct higher temperature (usually 350F).

Filling the fryer basket to the brim with product like fries, will actually lower the oil temperature. The result will be soggy product as they will take much longer to cook. Be consistent with the size of your fried items (uniformity) so that they cook evenly. The smaller the better.

F N Tip: Fill the fryer with oil to the designated "High-Level" or "Maximum" line & top-up daily if required. This will also keep your fryer temperatures consistent. Fryer oil expands an estimated 10% when heated. Overfilling the fryer will cause oil spills that will end up on the floor. Slippery floors near a fryer is an accident waiting to happen. Skin burns from hot oil take years to heal leaving permanent scars.

An external thermometer is key to the production of quality fried food. Service techs have noted that approximately 80% of commercial deep-fryers are not calibrated to the correct temperature. An external thermometer guarantees correct fryer temperatures - everytime. An external thermometer should be part of a quality kitchen. Fryer temperatures must be checked daily. At a costs of $20 from Amazon you must have one. Most models will fit in your pocket. Thermometers can check the internal temperature of various meats (proteins - chicken, beef, pork) to ensure they are cooked properly. Nothing worse than serving a customer chicken with a raw center. Undercooked meat is the major cause of Salmonella & E. coli poisoning.

Filtering - Passive & Active

Passive Method: - sending oil through stainless-steel mesh or paper filters

Active Method: - a chemical powder (Magnesium Silicate based - food grade) to remove debris & other fryer oil impurities. See "Oil Filter Aid-Magnesium Silicate" on the Kingsfield Inc. website.

Fry oil must be filtered everyday. Yes, everyday. I look at it like coffee. Coffee without a filtering process would be horrible. Filter twice daily, if you have self-filtering fryers.

Battered foods like chicken, shrimp, & fish leave an abundance of bits on the oil surface. Chicken, fish, & tempura designated fryers will require more filtration than french fry fryers. Many chains have fryers designated for french fries only to improve oil longevity & reduce taste transfers. No one wants fried chicken that tastes like halibut. If the oil smells bad, it is bad, throw it out. If in doubt, throw it out or use a 3M FFA Oil Test Strip for scientific based oil quality verification. 3M FFA Oil test strips may be purchased from Frylow Sales Inc.

Batter is a liquid consisting of egg, water, & flour. The excess batter turns into particulate (little bits) that burns in the oil turning to carbon. Excess batter must be "shaken off" the items before submerging into the fryer oil. Skimming must be done all the time & after every mealtime rush at minimum.


You were possibly wondering why commercial vegetable oil is packaged in brown cardboard 35lb boxes. Any type of light speeds the oxidation process of the oil. The same reason that expensive virgin olive oils are packaged in green glass bottles. Overnight & long periods between cooking, a cover for the fryers is suggested. Fryer covers will protect your fryers from light as well as air. This practice also prevents other foreign materials from finding their way into the fryers. We find that although pretty important, few restaurants use fryer covers? The Restaurant Store sells most fryer parts & accessories.


Oxidation is the process in which animal fat / vegetable oil gains oxygen or loses electrons. Oxidation will cause your fried product to absorb more oil making it greasy. Oxidation slowly makes the oil rancid, with off-flavors & bad smells. Smoking oil is a sure sign of deteriorated (ready to be replaced) oil. Hey Chefs .... smoking is bad!!. We don't know where the electrons go exactly but we know how to replace the fryer oil's electrons. I needed another "O" to spell "CASHFLOW". Sorry.


All wet product (typically after soaking or rinsing) must be dried off with a towel or paper towel before going into the deep-fryer. Oil & water do not mix, even in the deep-fryer. When frying frozen foods, it is important to fry right out of the freezer & never thawed. Be sure to remove ice chunks. Make sure to remove any excess frost or ice particles. Many chains, casinos, & restaurants prefer to fry directly from frozen. From box to fryer without touching human hands will ensure the ultimate in sanitary conditions. From Frozen to fryer does provide consistent fried common.

F N Tip: Cook high moisture foods at lower temperatures - crisp them at higher temperatures.