We Tried 7 Methods to Keep Apple Slices from Browning — Here’s the Surprising Winner
I’m a big fan of prepping ingredients in advance, but it can be tricky to keep some ingredients fresh until you need them. Case in point: apples. Once cut and exposed to air, the apple’s flesh begins to brown due to oxidation. And whether you’re packing up lunch for yourself or your kids, or you want to cut apples ahead to make apple pie or apple crisp, nobody wants brown apples.
The only way to stop oxidation is to create a protective barrier between the cut fruit and the air. Acid — usually in the form of citrus juice — has commonly been used to slow down this reaction, but there are a few other popular methods that use natural ingredients to interfere with the process.
To find out the best way to keep apples from browning, I tested six methods for treating the cut fruit based on common kitchen wisdom and popular methods found online, and then I compared the results side-by-side. The winner worked almost shockingly well.
A Few Notes About Methodology
Apples: For consistency, I used the same variety of apple (Pazazz, in this case) for each test, and cut each apple into 1/2-inch-thick slices.
Tests: For all methods, apple slices were treated and then tested two ways: left exposed to air at room temperature, and placed in a zip-top bag with as much air pressed out as possible. (Tip: While I used clear zip-top bags for my test, these methods would work just as well with a reusable silicone bag if you prefer those.)
For each method — with the exception of storing apple slices in water until ready to use — I soaked the apple slices for five minutes (or allowed the treatment to penetrate for five minutes) and then rinsed off with tap water before leaving the apples at room temperature.
As a control group, I left untreated apple slices on a plate as well as stored in a zip-top bag.
Ratings: Success was measured by the length of time before the apple began to brown and how the method affected the taste and texture of the slices.
Apple Treatment Method: Control Group (Untreated)
- Rating: 1/10
With no treatment, both the in-bag and on-a-plate apple slices started to brown within 15 minutes. So, as we already knew, this method is only good if you’re snacking on or cooking with the apple slices tout suite.
Apple Treatment Method: Lemon Water
- Rating: 3/10
Lemon water has been one of the most common solutions for home cooks trying to stop apples from browning for hundreds of years. So it has to work well, right? Wrong! I used 1 tablespoon of freshly squeezed lemon juice per cup of water. I soaked the apple slices in the water for five minutes, then rinsed in a colander under running tap water.
The lemon water-dipped slices stayed fresher in the zip-top bag than they did on a plate. Left exposed to air, they barely made it to the two-hour mark before starting to develop brown edges. In the bag, they stayed un-browned for another hour, which seems like a highly disappointing showing for one of the most well-known browning prevention methods.
Apple Treatment Method: Citric Acid
- Rating: 4/10
Citric acid might not be something that everyday cooks keep in their kitchen. This sour powder is most frequently used for canning and preserving, and also makes an ideal vinegar or lemon juice substitute if you’re making homemade ricotta. You can buy citric acid online or in the canning equipment section of many supermarkets and big-box stores.
Some food professionals recommend sprinkling citric acid on apples to prevent browning. I sprinkled 1/2 teaspoon of the powder over the apples and tossed them in a bowl to cover the slices evenly, then rinsed off with tap water in a colander after five minutes. And while it did stop the oxidation process in its tracks, keeping the apples un-browned for a full 12 hours, it also made the apple slices incredibly tart — even hours after the citric acid had been rinsed off.
This method works from a looks perspective, but I would only use it for apples that will be baked or cooked to hide the acidic taste.
Apple Treatment Method: Lemon Juice
- Rating: 5/10
Citric acid also comes in a non-powdered form, aka citrus juice. For this test, I treated apples with undiluted fresh lemon juice, squeezing half a fresh lemon over half a sliced apple and tossing in a bowl to coat the slices evenly. After letting the slices rest for five minutes, I rinsed the juice off in a colander under running tap water. These slices fared almost as well as the citric acid-treated ones did — the lemon juice stopped the browning for almost seven hours.
Taste-wise, the slices retained a lemon-fresh tartness, but were not as strongly acidic as those with citric acid. Lemon juice is better than citric acid from a taste perspective, although citric acid stops the browning longer. Plus, chances are you’ll have fresh lemons and not citric acid in the cupboard anyway, so I would choose the lemon juice treatment over the citric acid option. Just keep in mind that with both lemon juice and citric acid, the apples may be better suited for baking or cooking.
Apple Treatment Method: Lemon-Lime Soda
- Rating: 6/10
I had an ancient can of 7-Up in the fridge, so why not try the internet-recommended hack of soaking apple slices in lemon-lime soda to prevent browning? There is citric acid in the ingredient list, after all (behind water and high fructose corn syrup). I soaked the slices in soda for five minutes, then rinsed in a colander under running tap water.
Surprisingly, this worked much better than using lemon water. The slices on the plate looked fresh for nearly three hours, and in the bag for nearly six hours. This a good method, if you happen to have lemon-lime soda in your pantry, but don’t rush out and buy some just to keep your apples from browning — there are cheaper methods that work better!
Apple Treatment Method: Plain Water
- Rating: 8/10
If you’re slicing apples in the morning to be eaten at lunch, this is the easiest method. No pre-soaking or rinsing required here — you can prep while you’re half asleep. Simply slice the apples and store them submerged in tap water in a lidded container or sealed baggie at room temperature.
Sealed in a bag, the apple slices lasted a whopping six hours before starting to brown, and retained their crunch and taste. I also tested a batch submerged in water in a bowl without a cover, as you might do if you were slicing apples to make pie — this batch started to brown after four hours, presumably because without a lid the apples were still exposed to some air.
Apple Treatment Method: Honey Water
Honey is a natural preservative, with an acidic pH level, so in theory it would work to prevent apple slices from browning just as well as citrus fruit. And boy, did it come through with flying colors. For this method, I stirred in 1 tablespoon of honey per cup of room-temperature tap water, soaked the slices for five minutes, then rinsed them in a colander under running tap water.
The apple slices stayed fresh for 12 hours, both on a plate and in a bag. If there was any residual sweetness from the honey, I didn’t taste it; but then, honey and apples are a sweet pairing regardless. Because the apples still looked great after a day at room temperature, I put them in the fridge and let them rest overnight just to see if they would still be fresh in the morning. The bagged apples were still crisp and edible; the plated slices had shriveled slightly from the cold air.
The only reason I wouldn’t use this method again is because honey is more expensive than salt (see the winner below) and while I tend to hoard my honey for tea drinking and baking, I can always spare some cheap kosher salt.
Apple Treatment Method: Salt Water
- Rating: 10/10
For this method, I followed these instructions for the best way to keep apple slices from browning and dissolved 1/2 teaspoon of kosher salt per cup of room-temperature tap water, soaked the apples in the solution for five minutes, and then rinsed them in a colander under running tap water.
Just like the honey-treated apples, these slices didn’t get a hint of browning after 12 hours at room temperature, and did not taste at all like salt. Along with the honey-treated apples, I stored the salt-treated apples in the fridge overnight, and the bagged slices were still perfectly crisp and intact. (The plated slices had shriveled a bit, just like the honey apples.) This is my personal favorite method for preventing apple browning, and the one I’ll be using in the future.
Since most of the methods kept apples from browning for about two hours at room temperature, you can use whatever you have on hand for a short-term fix. After seven hours, all of the out-of-bag methods, except for citric acid, honey water, and salt water, showed some signs of browning. Kept in zip-top bags, the apples that had been treated in salt water and honey water lasted through the night in the refrigerator.
This post originally ran on Kitchn. See it there: We Tried 7 Methods to Keep Apple Slices from Browning and the Winner Might Surprise You