Learn the science behind:
After having finally figured out what an air fryer really is (not a true replacement for a deep fryer, but it’s close, we’d describe it as: a very efficient convection oven), it was time to really put it to the test. Potatoes seemed like a good first experiment to truly better understand how an air fryer works. There are a lot of ways to prepare potatoes in the air fryer, each highlighting different strengths and options of the air fryer!
To put this air fryer to the test we decided to set up three ‘food science’ experiments. The first two focus om making french fries, the third aimed to replicate oven/pan-fried potatoes:
- Frozen fries: Making french fries can be quite cumbersome, it’s probably why buying pre-fried frozen fries is such a popular option. All you need to do is ‘finish’ them off. We compared doing so in the oven, deep fryer, and of course the air fryer.
- From scratch: We then also wanted to test making fries from scratch (aka from fresh potatoes) in the air fryer, so did those next.
- Pre-cooked potatoes: Lastly, we tested making pan-fried potatoes in the air fryer, using par-boiled potatoes. Would they crisp up just as nicely as finishing them of in a pan would?
Test 1: Air-frying store-bought frozen fries
Making a good french fry that is crispy on the outside and soft within can be challenging. Choosing the right potato, cutting it, double frying that potato, there’s a lot of ways to not get that ideal fry. But people love french fries and they’re best eaten right after they’re made or they’ll get soggy!
It’s probably why using frozen fries is a popular option. Manufacturers have already made sure to choose the right potato variety and cut the potatoes. What’s more, they’ve already pre-cooked them, by frying them once, right before they’re flash frozen. This ensures that the whole potato has already been ‘cooked’ through to get that soft-cooked center throughout. All that needs to be done at home (or in the restaurant) is to fry them once more. This last fry not only thaws and heats the fries, it also creates that crisp outside.
An air fryer happens to be suited perfectly (according to the theory at least) for that last fry step. The air fryer heats up quickly and is great at producing a thin crispy dried crust on the outside of your food. As such, we put them to the test.
We prepared these store bought fries three ways (following the instructions of the manufacturer):
- Air fryer: 10 minutes at 200°C
- Oven: 18 minutes at 220°C
- Deep fryer (in oil): 5 minutes at 180°C
Notice the difference in time required for each method. As we discussed when evaluating the air fryer, as well as when comparing the oven vs. a deep fryer, this is to be expected. Oil can transfer the same amount of energy (heat) into the fry a lot faster than air can (thanks to its high heat capacity). An air fryer again is a lot faster than an oven since the air moves through the fries way more efficiently and aggressively.
Using these three prep methods to prepare our frozen fries did not result in any discernible differences. As you can see below, all three fries looked very similar. They also tasted identical and had the same amount of crunch + softness. We weren’t able to taste the difference at all.
Test 2: Making french fries from fresh potatoes
Of course, using frozen fries is a little bit of short cut. Since the pre-frying isn’t controlled by ourselves, but by our supplier, there still is a little bit of a black box. As such, next up we wanted to tackle and own the whole french fry making process!
As you can read in our post dedicated to making french fries, making fries in the “traditional” way involves a 2-step frying process: a pre-fry at 160°C to cook the potatoes through and a second fry at 180°C to brown the fry and make it crunchy. We were going to test which of those steps (whether it’s one or both) could be taken over by the air fryer.
We used one batch of potatoes for this test to ensure that differences between batches (or varieties) would impact our results. We cut all the potatoes in the same thickness using a fry-cutter. Next, we prepared them in four different ways:
- On day 0: pre-fry in oil at 160°C. On day 1: finish off in the air fryer at 200°C for approx. 10 minutes.
- On day 0: pre-fry in oil at 160°C. On day 1: finish off in the deep fryer at 180°C (until they’re as brown as the fries from test 1).
- Pre-fry in oil at 160°C on the day itself. Cool for approx. 10 minutes, finish off in the deep fryer at 180°C
- Place the potatoes into the air fryer for approx. 20 minutes (until they’re as brown as the fries from test 1).
This time we did notice some differences, especially for the fry that hadn’t seen any oil.
The first two fries, the two varieties that had been pre-fried the day before, came out almost identical. We wouldn’t have been able to tell the difference. The fries fried twice on the same day weren’t far off either, but were just a tad more greasy.
The air fryer fries were a bit of a disappointment and very different than the rest. They weren’t that well-cooked within (though their outside color was similar to those of the other fries) and they lacked flavor. Also, they clearly looked different and were more wrinkly and seemingly dried out (without being crispier).
Test 3: Par-boiled potatoes
Our last and (spoiler alert!) favorite preparation method in the air fryer involved using par-boiled potatoes. By now we had concluded that the air fryer is great at getting a crunchy outside. However, it’s just not as good at cooking the inside of the potatoes. Considering how an air fryer works, this made a lot of sense. As such, we tested to see how the air fryer would handle potatoes that had been pre-cooked, just not in oil. This way, replicating the pan/oven-fried potato process.
We investigated two ways to pre-cook our potatoes before air-frying:
- Use store-bought pre-cooked potato pieces. These came par-boiled, pre-cut. We simply threw them in the air fryer according to the manufacturer’s instructions (approx. 20 minutes).
- Pre-cook raw, unpeeled, and uncooked potatoes in the microwave. How long a potato should be cooked for in the microwave strongly depends on its size. In our case, approximately 8 minutes cooked our potatoes through. Once pre-cooked, the potatoes were cut into wedges before being air-fried.
Both methods were highly successful. In the case of the microwave potatoes, a mere 10 minutes in the air fryer did the job of crisping them up perfectly. What’s more, by cutting the potatoes only after they were pre-cooked, the slices weren’t as smooth on the sides. This is actually great for getting more crunch, all those rough little edges dry out more easily and crisp up beautifully.
This test was a great example of using the optimal tools to get a specific job done. A microwave is great at heating food through. Since the waves of the microwave travel through the food it can evenly cook a large food rather quickly. This as opposed to boiling, grilling, and frying, where the heat starts from the outside and has to travel to the center slowly. Cooking a potato in a microwave, or par-boiling it in water will not result in a crispy outside though. That’s where the air fryer comes in. The air fryer simply lightly dries out and bakes the outside.
Normally, we would have finished these potatoes off in a pan with some oil, or maybe in a regular oven. In the regular oven they would have taken significantly longer. In the case of the frying pan, we would have needed more oil (to prevent sticking) and a lot more work. The air fryer simplified things a lot here.
What we did not test (and why)
Of course, there are a lot more ways to prepare a potato. However, we stuck to methods that result in crispy crunchy potatoes, and for good reason. Based on our earlier research an air fryer is great at:
- Quickly heating up, but, just like in the case of an oven, that heat needs to penetrate into the product. As such, it takes a while for the center of a food to cook (and you risk burning/drying out the outside before cooking the inside if you’re not careful)
- Drying out and crisping up your food thanks to the efficient heat flows.
As such, we did not test making a large baked potato in the air fryer. We definitely could have, and it would have worked. However, recipes online state needing at least 40 minutes to make one. That’s not that much faster than a regular oven. Also, it’s a lot slower than if you would use a microwave.
Our recommendation for baked potatoes and air fryers: pre-cook the potato in the microwave (as we did in our third test as well). Then, if you’re looking for that crispy outside, sure, put it in the air fryer for a few minutes!
Mashed potatoes are all about creating that soft, almost creamy, smooth texture. For a good mashed potato, you need a nicely cooked potato (with enough remaining moisture) to mash it into a puree. Using boiling water or a microwave to cook your potatoes is more efficient than using an air fryer. That doesn’t mean it can’t be done. We just don’t think there’s a benefit to using an air fryer here.
When it comes to preparing potatoes there are tons of good ways to do so. Based on these tests, we can conclude that using an air fryer is one of many good ways as well. That said, we do believe that combining an air fryer with another pre-cooking method (e.g. our favorite of using the microwave) gives the best result. Let the air fryer do what it’s good at (crisp & heat) and let other technologies do what they’re best at.
A last final note on the air fryer that’s worthwhile mentioning is just how easy it is to use an air fryer. It’s really a set-and-forget-it system. You might want to shake your potatoes once midway, but there’s no monitoring of the heat, shaking a pan, adding oil. It’s pretty (but never completely) foolproof. For busy high traffic situations, this is great since it makes it so much easier to control the process!
All tests were done with a Philips Viva air fryer, regular size (no longer sold)