True or false: Deep-frying is classified as a "dry heat" cooking method.
Would you believe that the answer is "true"? It may seem counterintuitive, given the oil involved, but deep-frying falls into the "dry heat" category, meaning that heat is imparted to food without the aid of some form of water. The same is true of sautéing or panfrying. If you're a fan of all things crispy and tender—think fried chicken or fish and chips—then deep-frying is for you.
When done properly, deep-frying will create a shatteringly crunchy exterior while keeping the interior nearly free of oil. When it comes to results, there's a fine line between golden-brown and greasy, so read on for eight tips to deep-fried domination.
1. Not All Oils Are Created Equal
The first step to the best-ever fried food is choosing the right oil. It's essential to consider the oil's taste and smoke point before firing up your bubbling cauldron.
The taste of an oil is determined by its origin. For example, canola oil, which is made from the rapeseed plant, tastes fairly neutral, whereas olive oil has strong fruity and floral notes, depending on the variety of olive used. Taste is a matter of personal preference, yet smoke point comes down to sheer science.
The smoke point of oil is the temperature at which the oil begins to decompose and give off visible smoke and fumes. During this process, the structure of the oil molecules begins to break down, which creates acrolein, a noxious-smelling compound. For this reason, deep-frying requires an oil with a high smoke point (typically above 375°F) so that the molecules don't break down too quickly at high temperatures. Oils with high smoke points include peanut, safflower, sunflower, and canola.
2. Where There's Smoke…
The oil temperature can rise quickly between the smoke point and flash point, at which tiny wisps of flame appear. A majority of oils reach their flash point at about 600°F. If oil continues to be heated to even higher temperatures (about 700°F), it will reach its fire point, causing a full-blown blaze.
Hot oil is nothing to mess with, so a quality deep-fry thermometer is an essential piece of equipment. Use it to accurately gauge and consistently maintain the temperature of your oil. Frequent heat fluctuations can be dangerous and will shorten the life span of your oil because it oxidizes faster at higher temperatures.
3. Like Oil and Water
Water is oil's worst enemy. Not only do the two liquids not mix, but adding water to hot oil will actually cause an explosion. Keep your work area clean, but more important, completely dry. Never store water around your deep fryer or on a shelf above the stove.
All foods should be thoroughly patted dry with a paper towel prior to being submerged in hot oil. If you are using a wet batter, such as for tempura or onion rings, be sure to shake off any excess batter before frying to guarantee splatter-free success.
4. Fry First, Salt Second
Salt is an essential ingredient in any deep-frying recipe; however, timing is everything when it comes to seasoning. Never salt a food before deep-frying it, as the salt will draw moisture (read: water) to the food's surface and cause the hot oil to splatter. Salt also lowers the smoke point of oil, which in turn breaks down the oil molecules more quickly. Always salt a food immediately after removing it from the hot oil, when it has the best chance of sticking to the food.
5. Heavy-Bottomed Cookware Is Best
Expensive deep-fryers are not required for frying at home. All you need is a large, heavy-bottomed pot, which allows you to keep the temperature of the oil steady. A thicker bottom guarantees the heat will slowly warm up the oil, whereas a thin bottom may bring the oil to an unsteady boil at a moment's notice.
In addition to a heavy bottom, your pot should have tall sides to accommodate the depth of oil your recipe requires and to leave at least 4 inches between the top of the oil and the top of the pot. The oil will rise and bubble as the steam escapes from the food, so you need to have extra room to keep it from overflowing onto the stove. A few splatters are inevitable, however, so steer clear of deep-frying unless you're wearing long sleeves and an apron.
6. Fry, Baby, Fry!
The "low and slow" approach does not apply to deep-frying. The technique is meant to be fast: Food is plunged into the hot oil, cooked just until golden, and then quickly plucked out with tongs or a long-handled wire mesh strainer before it has the chance to absorb any excess oil.
Once a food is cooked, it begins soaking up oil at a quicker pace, so the real key to avoiding a greasy glob is to get the food in and out of the oil in the minimum amount of time possible while still ensuring it's fully cooked. Adding food to hot oil will also immediately cause the oil temperature to drop, so make sure you allow the oil to return to the original temperature in between batches.
7. Strain to Extend Shelf Life
Some experts argue that you can strain and reuse your cooking oil. Keep in mind, however, that the oil has already begun to break down from the heat, causing undesirable compounds to form. So if you do want to reuse your oil, allow it to cool until the pot is safe to handle, and then filter it through a fine-mesh sieve to discard any larger particles. Store the recycled oil in the fridge until ready to use. Whatever you do, do not mix used oil with new, because old oil—no matter how many times it's strained—will contain food particles you'll want to keep separate from the clean oil.
8. Reuse, Recycle?
Even though you can reuse oil, it won't last forever. High heat, water, air, and burned food particles all break down oil molecules over time. Unsure if your oil is past its prime? Look for any of these telltale signs that it's time to toss the batch and start fresh: excessive smoking at normal temperatures; strong discoloration; rancid smell; and excessive foaming around the frying food. When disposing of used oil, be sure to cool it completely before discarding it in the trash, and avoid plumbing disasters by never pouring oil down the drain.
Armed with our list of tips and tricks, it's time to put your deep-frying skills to work on crispy French fries, doughy beignets, spicy jalapeño poppers, cheesy mozzarella sticks, and more. So pick your oil, monitor the temperature, and you'll be on your way to achieving golden-brown deep-fried perfection.
Hervé Riou is a chef-instructor at the Institute of Culinary Education. He was 15 when he started an apprenticeship at a two-Michelin-star restaurant in Laval, near his native Brittany. A member of the invitation-only Académie Culinaire de France, Riou is also a volunteer EMT in Glen Cove, New York, a member of the U.S. Coast Guard Auxiliary, and an avid sailor.