Have you ever thought that French fries should be renamed to American fries? I mean studies have shown that we eat more than 30lbs of French fries each every year. To microwave French fries is fairly easy except for the frozen French fry. If you have frozen fries, you'll need to take greater care in preparation.
Also, the name ‘French fries’ is actually a misnomer, the French fry has been traced back to 1600 Belgium when the poorer population would saute or fry offcuts of potatoes as a good energy source during the frigid winters.
The first time we encountered them was during World War I when the Belgiums, who were hosting the Americans and British, served a dish they had in common with British ‘potato chips’.
Because of the shared language between Belgium and France, these ‘fried potato chips’ became known as French fries and later just Fries.
As we’ve said above, Americans consume more of these crispy potato morsels than any other nation and I mean, can you blame them.
This American staple is relatively easy to make, with only 2 ingredients (oil and potatoes) they are super accessible and serve a great purpose as a stop-gap between crispy hashbrowns and silky smooth mashed potato.
This dish marries the 2 dishes perfectly offering a crispy, golden exterior with a soft, fluffy interior that’s just unachievable with any other potato dish.
Leftover French fries is not something we can always relate to but it does rarely happen. But when you’ve had a particularly big portion of fries or your eyes were a bit too big for your stomach and you’re forced to either put away or trash your remaining fries it can be a sad day.
Don’t worry though because even though you might feel like you’re breaking up with your BFF or giving up your childhood blankey we can help reunite you.
What I’m talking about is the common disappointment that is day-old fries. They become soft, slick, chewy, and somehow dry, a distant memory of the once great French fry.
In terms of food safety, it is completely safe to reheat fries, the issue is with the storage. If you don’t immediately store your fries in the refrigerator after you’ve eaten as much as possible a bacteria called botulism could start to grow.
Botulism is one of the bacteria that cannot be completely eliminated with reheating. Botulism starts to grow as the fries cool down from hot to room temperature and the longer they sit at room temperature the more likely botulism is to grow.
The quicker they cool down the better so if you think you’re going to have leftovers refrigerate your fries immediately.
The best way to deal with limp and lifeless leftover fries is to re-fry them. Add about 1 tablespoon of oil into a deep-set skillet (bigger is better) and fry your old fries for about 3 minutes, tossing them and then fry again for another 3 minutes.
They’ll come out crispy and fluffy and almost as good as the day before, some of the salt may have seeped out of the fries overnight in the refrigerator so salt to taste.
If however you don’t want to mess around with hot oil on a stove and you’re just trying to get your fry on immediately then the microwave might be your best option.
We’ll set out a few different ways you can reheat those once crispy potato slouches so that they turn out crispy and actually edible.
The reason there is a textural difference between the outside of the fry and the soft fluffy center is because of the temperature they are cooked at.
Deep frying causes any moisture droplets caught in the outermost layer of the potato sticks to boil away and evaporate.
This creates spaces within the crust of each fry that when compressed in your mouth snap and give off a crispy effect. This effect is similar to a microscopic hardened potato sponge covering a mushy potato center.
Unless saturated by the frying oil, this space technically has less water content than the center of the fry and the surrounding atmosphere. This is where the fry becomes soggy.
The water within the fry wants to escape as it’s currently hot and steaming, unfortunately, it’s being trapped by the beautifully crisp outer layer so some of the moisture inevitably saturates the crispy outer layer and causes it to lose some crispness.
The other problem is that if the steam manages to escape it then may be trapped by the container that the fries are kept in. This creates a bit of a lose, lose situation for the fries as regardless of what happens they’re bound to become soggy.
All hope is not lost, to avoid some of the moisture retention the first thing you can do is store your leftover fries in an open container so as to let the steam that does escape out, stay away from the fragile outer layer. The next thing is in the reheating process.
When you reheat the fries in your microwave you want to make sure the steam that does need to escape, can do so.
The microwave is a great place to trap moisture as you’re enclosing your food in a steam trap (microwaves are great for quick vegetable steaming for this very reason) which makes it unideal for reheating crispy foods like our French fries.
To counteract this effect you’ll want to find a method of either attracting the steam away from the fries or allowing enough clearance for the steam to stay away from the fries once it escapes.
We have 3 methods to help with this issue that we’ll go into soon.
The other issue with the microwave is that it heats foods from the inside out so an effective way of making sure the generated steam stays inside long enough for the outside to heat up is imperative.
Here’s a few sure-fire ways to breath life back into your leftover fries and ensure they keep that trademarked crispy exterior:
Method 1 (Oil):
Method 1 is the easiest but also the most unreliable method depending on the fries you’re trying to rejuvenate.
What we’re aiming to do with this method is to saturate the outer layer of fries with some oil so that the steam trying to escape stays away from the crispy exterior.
This whole method works because of the middle school rule that oil repels water. Also, the oil heats up relatively quickly in a microwave which will cook the outer layer of your fries more evenly.
A word of warning though, this method will not work with chunkier steak fries as there is simply too much moisture in the center to protect the crispiness from, for McDonald’s fries this should work 9/10 times.
Remove your fries from the refrigerator and leave them to stand for 15 minutes, remember the longer they sit at room temp the more dangerous they are so 15 minutes is the maximum.
Put your fries and oil together in a bowl and toss to coat making sure all fries are lightly coated, use more oil as necessary.
Spread the oiled fries evenly over a microwave-safe dish making sure not to crowd the plate. If you have too many fries do them in separate batches.
If you have a mesh or well ventilated splatter guard place this on top of your dish, if not leave them uncovered.
Microwave the fries on 75% power for 5 minutes, removing and agitating halfway through.
Once heated all the way through, salt your fires and leave to stand for 2 minutes uncovered before consuming.
Method 2 (Paper towel)
With this method, we’re attempting to catch any released moisture before it can sog the fries.
We’ll still be using oil to try and capitalize on its moisture trapping and heating abilities but we’re adding a second layer of defense against the dreaded steam.
A microwave-safe dish large enough to spread out the fries.
2 or 3 squares of paper towel.
Salt to taste.
We’re foregoing the splatter guard here for some paper towel, so make sure you have enough to cover your fries and follow these steps:
Remove your fries from the refrigerator and leave them to stand for a maximum of 15 minutes.
Put your fries and oil together in a bowl and toss to coat making sure all fries are lightly coated, use more oil as necessary.
Place your 3 (still connected) squares of paper towel onto your microwave dish with the center square being in the center of the dish so that the 2 outer squares drape over the sides of the dish like wings. If you’re using 2 squares then only 1 square should be in the center of the dish with the other draping over the side.
Spread the oiled fries evenly over your paper towel covered dish. making sure not to crowd the plate. If you have too many fries do them in separate batches.
Wrap your oiled fries with the 1/2 previously draping outer squares of paper towel.
Place the fries onto a dry dish, salt to taste, rest, and dig in.
Method 3 (Crisping tray)
This method requires you to have a crisping tray so if you haven’t got one then the 2 above methods will do you better.
A crisping tray essentially turns your microwave into a speedy little grill, the heavy base inside the crisping/grill pan attracts all the heat and distributes it to the food and the included lid traps it in so the food is evenly cooked.
This method not only works for reheating your fries but you can even prepare fresh fries this way. The grill formed bottom gives your fries enough room to sweat without trapping that steam.
Essentially if you’re looking for the best alternative to a skillet or air fryer then this is your best bet.
What you’ll need:
1-2 Tablespoons of olive or vegetable oil.
A large bowl.
A Microwave crisping/grilling tray/pan.
Salt to taste.
If you’ve been using a microwave crisping tray for a while you’ll know exactly what to do but if not then just follow these steps, your times may vary depending on the power of your microwave but anything over 1000W should be fine:
Remove your fries from the refrigerator and leave them to stand for 15 minutes, remember the longer they are at room temp the more dangerous they are so 15 minutes is the maximum.
Put your fries and oil together in a bowl and toss to coat making sure all fries are lightly coated, use more oil as necessary.
Spread the oiled fries evenly over the grill surface of your tray/pan, if you cannot fit them all over a single layer then do multiple batches.
If you have one place the included lid over the fries and place them in the oven. If you didn’t get a lid included then place a single paper towel over the fries.
Microwave the whole tray on full power for 10 minutes, agitating halfway through, and check the exterior of the fries for the desired doneness.
If doneness isn’t achieved then place them back in the microwave and blast for a further 2-3 minutes.
Salt your fires in the tray/pan and toss to combine.
Remove your fries from the tray/pan and place them on a dish for 2 minutes before eating.
Round-up
As we stated above if your fries were stored correctly then reheating them any of the 3 ways we’ve included they should be completely safe to eat.
Remember to make sure that you cool your fries down as quickly as possible if you can’t consume them in one sitting.
Try not to reheat fries more than once, for one reason they will turn out rubbery and dry and also because they would have sat at room temperature for longer than the recommended amount of time.
We were going to include a method that depended on you having a combination grill/microwave but at that point, you’re better off just using a conventional oven.
This article is for accessibility, we don’t want to exclude anyone with a standard microwave.
If you do have a combination grill/microwave then throw your oiled fries in there on the combi setting for 5 minutes and you’ll have much greater results than standard microwaving.
Apart from that though a skillet and direct heat will always be the best option. Happy frying.
Cassie brings decades of experience to the Kitchen Community. She is a noted chef and avid gardener. Her new book "Healthy Eating Through the Garden" will be released shortly. When not writing or speaking about food and gardens Cassie can be found puttering around farmer's markets and greenhouses looking for the next great idea.
