There’s no denying America’s love of deep fried foods. It’s not the most elegant way to cook food, and certainly not the healthiest, but it’s a necessary tool. And let’s be honest…. fried foods are delicious. While we’ve become experts at eating them, some of us are a little challenged when it comes to deep frying at home. By learning just a few simple tricks, you can learn to deep fry your favorite fried foods with even better results than you find when eating out.
Deep frying: completely submerging food in oil at a high temperature.
Even though oil is considered a liquid, deep frying still qualifies as a dry heat method (moist heat methods require water). It’s similar to pan frying but requires that the food not touch the bottom of the pan while cooking. Consequently, more oil is required for deep frying than pan frying.
Most foods will float near the oil’s surface when being fried. Heavier foods will drop to the bottom of the pan but will often float to the top when they are cooked. Extremely light foods will float on top of the oil and will either need to be weighed down (often with a fryer basket in commercial kitchens) or turned halfway through the cooking process for even browning.
Most foods are fried in oil between 325°F and 375°F. Very rarely (if ever) would you fry outside that range: frying at a lower temperature means the food will absorb more oil (not ideal) while the outside develops little color. Frying at a higher temp would overcook the outside and undercook the inside.
Choosing Oils for Deep Frying
Peanut oil is a popular choice for frying among home cooks, often chosen for its “high smoke point”. Peanut oil is definitely good for frying but, my friends, I’m here to tell you that it’s not necessarily the best option.
smoke point: the temperature at which heated fat or oil starts to break down and burn, giving an unpleasant taste to food
I’ve done extensive research as to the smoke point of different oils and I don’t think I’ve seen two sources that agree on temperatures across the board. It’s actually puzzling how so many sources can come up with different answers. Since I can’t count on any single source, I decided to rely on Statistics 101: eliminate the high & low numbers and take the mean of what’s left. According to my research here’s a list of oils and their smoke points:
If we rarely (if ever) fry food above 375°F, why do we need peanut oil’s high smoke point? Since peanut oil doesn’t even have the highest smoke point of available cooking oils, there are two possible answers to that question: marketing or ignorance. Either someone spent a lot of money on a campaign to convince us we need peanut oil’s high smoke point or some bonehead once said that peanut oil is best for frying and others followed along. Either way, they’re wrong. Any of the oils on the list are good for all deep frying except coconut oil and often lard. I included lard because it can be used for lower temp frying and coconut oil because people love it right now. I like canola oil* for deep frying for several reasons:
- it has little to no taste so my food won’t pick up flavors from the oil
- its smoke point is over 400°F and since I don’t fry anything over 375°F, that’s high enough
- it’s among the most inexpensive oils… bonus
- it comes from one source (rapeseed) so it’s not a mystery mix of other oils (ahem, vegetable oil)
Do your pocketbook a favor and “just say no” to frying in peanut oil. There are much better things to waste your money on.*I only use organic, non-gmo canola oil. I’ll write about why soon in another post.
It seems like such a waste of resources to fry a few foods in a huge vat of oil then throw it all away. For this reason, many home cooks strain the used oil through a sieve and/or cheesecloth to get any floating bits out then store it for re-use. It’s perfectly acceptable to do so, especially if you’re on a tight budget, but there are some drawbacks. Among them, used oil doesn’t last forever and I’ve read about some possible health concerns.
Using Old Oil
Oil turns rancid when it gets old and picks up a not-so-pleasant taste when it has been used too many times. Since the shelf life of oil depends on a number of factors (the type of oil, storage climate, how it’s cooked, etc.), there’s no magic formula to tell you how long your oil will last. You’ll have to rely on the ‘best by’ date and your own senses.
It’s hard to describe the taste of old oil but more than anything you’ll taste bitterness. Oil that is turning rancid may also smell like a crayon (weird, I know) so channel your inner five-year-old when checking the oil in your pantry. Sadly, most of us are unknowingly familiar with rancid oil. Too many restaurants use oil far too long so we’ve become immune to the taste, making it harder for some to identify. Old oil makes food taste more bitter and leaves your mouth excessively greasy.
Personally, I don’t fry enough food to keep used oil around so I usually toss it after each use. I’ve strained used oil and kept it a few times but I don’t think I’ve ever saved it after a second use. It’s just a personal preference so if you keep it longer you’ll get no judgement from me. But for the sake of a good meal, throw that stuff out when it affects the flavor of your food!
Possible Health Concerns
Some scientists insist trans fats form when any high-temp oils (like the ones listed above) are heated over 120°F. I’ve done quite a bit of research on the subject and couldn’t find an abundance of information (relatively speaking) but some suggest the longer the oil is over 120°F, the higher the chance of trans fats (up to 4.5% by volume). The trans fats don’t disappear when the oil is cooled so they recommend you always start with fresh oil. Or avoid deep-fried foods altogether.
Like I said, there’s not an overwhelming amount of information about trans fats in hot oils so you’ll have to read up to make the best decision for you and your budget.
Blanching in Oil
Have you ever wondered why restaurant french fries are so much crispier than fresh ones cooked at home? Granted, most restaurants use a frozen french fry that’s coated in a scientific experiment to not only create crispiness but to ensure the crispiness survives under heat lamps for prolonged periods (I worked in foodservice distribution for almost six years so I can name names, although I’m sure you can name a few). Some restaurants do it the old-fashioned way and cut the potatoes in-house but they’re still able to crisp them up nicely. The answer, as suggested by the title of this section, is blanching.
The idea is this: if you fry the potatoes at a low temperature, they’ll get nice and soft on the inside. Then if you fry the blanched potatoes quickly at a higher temperature, the outside will crisp up nicely. The folks at Serious Eats tried it several different ways to test out the theory and they found the popular restaurant technique to be true (although their solution is a little off, but that’s irrelevant). I’m going to give you the recipe for perfect restaurant-style french fries but before we get there, let’s cover some must-knows about deep frying:
Choose the right equipment.
I like using my wok (like this one, carbon steel is best) because the narrow bottom means I use less oil. The steel heats up quickly and the shape of the wok helps keep the oil temperature consistent. (Make sure you use a wok ring when deep frying on your stove top if your wok has a round bottom.) Dutch ovens are a great choice because cast iron also keeps the oil temperature consistent. Of course, residential deep fryers work well but I would only get one if you think you’ll get your money’s worth out of it.
You’ll need more than just a sturdy pot for frying, though. You need utensils like tongs for big items or a spider strainer for smaller foods. You’ll also want a plate or flat pan to hold your cooked food. Line it with paper towels or a wire rack (or both) to allow the excess oil to drain off the food.
Oil temperature is key.
Have a thermometer handy for best results. Preferably a candy thermometer that you can clip to the side of your pot. If you don’t have a thermometer, use the old school method of dropping a 1-inch square of bread into the hot oil; if it rises to the surface crackling and frying, the oil’s hot enough. If it browns uniformly in:
- 60 seconds, the temperature is about 350 to 365°F
- 40 seconds, the temperature is about 365 to 382°F
- 20 seconds, the temperature is about 382 to 390°F
Fry dry foods.
Remember: oil and water are rivals but hot oil and water are sworn enemies. Like Hatfield/McCoy kinda enemies. Watery food in hot oil will cause the oil to bubble ferociously and has caused more damaging fires than one could count so make sure your food is as free of water as possible.