Keep apples from browning with salt

No matter how fresh and crisp apples are, they aren’t appetizing once they’ve turned brown—which takes a grand total of about two minutes. Unfortunately, browning isn’t just unappealing, it also alters the apple’s taste and nutritional value. But why does your favorite fall fruit brown so quickly? When an apple is cut, enzymes (and iron in the apple) chemically react with oxygen. The fruit quickly begins to oxidize, and its flesh turns brown. Essentially, the apple begins to rust right before your eyes.

It's enough of a problem that the USDA recently approved an apple that's genetically modified to not brown when sliced (it's America's first approved genetically modified apple—yay?). But how do you keep apples from turning brown if you’re not down with new-and-improved GMO’d apples? There are a few old-fashioned tricks to prevent your apple slices from oxidizing.

Photo by Shutterstock

Plain Water

The most important thing you can do to avoid browning is to reduce the apple’s exposure to air. And the simplest way to do that is to submerge your apple slices in water. Since the slices will float to the top of the water, place a clean paper towel on top. Once the paper towel is wet, it will push the apples under the water's surface. Another technique is to put the apple slices in zip-lock bags with the air pressed out. Neither of these techniques call for additional ingredients, and both work great for keeping the apples from browning.

Water and Salt

Dissolve 1/8 teaspoon of salt into one cup of water—always be careful not to add too much salt. Then add in the apple slices, let them soak for a few minutes, then drain them. Give the slices a quick rinse in fresh water after you drain them, so your fruit won't taste salty.

Water and Honey

Stir two tablespoons of honey into one cup of water and soak your apple slices in the mixture for 30 seconds. This works because there is a compound in honey that stops the enzyme responsible for oxidation. Additionally, this is one of the methods that will not unpleasantly alter the apple's taste.

Citrus or Pineapple Juice

If you want to take the submersion method up a notch, you can add a little bit of citrus or pineapple juice to the water. What do these juices have in common? They contain citric acid, which slows the chemical reaction and prevents browning. But there are actually a few ways to use juice in order prevent browning: 1) you can add two tablespoons of juice to water and submerge the apple slices, 2) you could submerge the apples into juice, or 3) you can simply squeeze lemon, lime, or orange directly onto the surface of the cut apple. The only downside of using this method is that the juice will impart a little bit of flavor onto the apple—so pick your favorite.

Treat and Keep in an Air-Tight Container

Again, the most important part of keeping apples from browning is to reduce or eliminate the apple’s exposure to air after it’s been cut. After you’ve chosen a method and treated your apples, store them in an air-tight container, this could be Tupperware or even a zip-lock bag. Then, keep them in the fridge.

Although there’s no absolute way to prevent apples from turning brown forever, these methods will offer an additional hour or two before discoloration begins. So you no longer have to scarf down your apple slices at record speed, and you can keep 'em looking fresh and tasty on fruit platters and in salads for way longer than apples that are untreated.

You’ve been thinking about the apple slices and peanut butter in your lunchbox all morning. But thanks to meetings and conference calls, it’ll be a race against the clock to eat them before they turn brown and mushy. It turns out there are a few ways to keep your favorite healthy snack crisp and fresh longer. Learn how to keep apples from browning with these six easy methods.

Why Do Apples Turn Brown?

Just like avocados, brown apples are safe to eat; they’re just less appetizing. Browning (or enzymatic browning if you're fancy) is a natural chemical reaction that occurs when oxygen comes in contact with polyphenol oxidase, an enzyme found in various fruits and vegetables. Oxidation can lead to a change in the appearance of fruit, as well as a decrease in flavor and nutrition. 

If you’re going to slice an apple and eat it immediately, don’t go through the trouble of treating the slices. Just know that the longer they’re exposed, the browner they’ll get. If you’re slicing hours (or even days) in advance, these methods can help it maintain its natural color, at least for a while. To store sliced apples, always use an airtight container or a resealable bag with all the air pushed out of it.

How to Keep Apples from Browning

1. Brush or Dip the Apple Slices in Lemon Juice

It’s the oldest trick in the book. Lemon juice’s high acidity and low pH deactivates the enzyme that causes browning. Essentially, the acid reacts with the enzyme before the enzyme and oxygen have a chance to react with the apple. Ever wonder why store-bought apple slices are always so white and crunchy? They’re often treated with ascorbic acid, citric acid or sulfites—lemon juice (another acid) works the same way.

Give the apples a quick spritz of lemon juice, or dilute a few drops of lemon juice in water and soak the apple slices. No fresh lemons? Try bottled lemon juice, lemonade or even orange juice—as long as it’s acidic, it’ll slow browning. Vinegar works too because of its acidity, but it’ll potentially impart a more unpleasant taste than these other alternatives. If you’re freezing farmers market Honeycrisps for a future batch of applesauce or apple bread, lemon juice is your best bet.

1. Wash and slice the apple.
2. Fill a small bowl with cold water and the juice of half a lemon.
3. Dip the slices into the mixture. Eat or store for later.

2. Soak the Slices in Saltwater

You may remember from chemistry that salt is also called sodium chloride. Its namesake chemical components keep oxygen from reaching the surface of the slices. After all, it’s nature’s oldest preservative. Just be super careful not to add *too* much salt. Using ½ teaspoon or less in a cup of water will get the job done without altering the apple’s taste.

1. Wash and slice the apple.
2. Dissolve the salt in cold water.
3. Add the apple slices to the saltwater and let them soak for about 3 to 5 minutes.
4. Drain, rinse and dry the apples. Eat or store for later.

3. Submerge the Slices in Honey Water

Thanks to a peptide compound found in honey, this method deactivates the browning enzyme. Cook’s Illustrated found that a good soak kept the slices white for more than a day while a 30-second dunk kept browning at bay for eight hours. This trick also works for veggies like potatoes and other fruits like pears. (And it tastes good to boot.)

1. Wash and slice the apple.
2. Dissolve 2 tablespoons honey in 1 cup water.
3. Dunk the slices in honey water for at least 30 seconds and no more than a few minutes.
4. Remove, rinse and eat or store for later.

4. Submerge the Slices in Liquid

It works like a charm if you don't have any of the other quick fixes on hand. The idea here is that the oxidation process can’t start if the apples aren’t exposed—and they can’t be exposed while in liquid. Some swear by soaking apples for 3 to 5 minutes in a ginger ale or lemon-lime soda that contains citric acid, but we like avoiding the extra sugar and using club soda or water.

1. Wash and slice the apple.
2. Fill a bowl with cold water and add the apple slices.
3. Top the bowl with a paper towel. Once it’s wet, it will submerge the floating slices.
4. Remove the slices after about 10 to 15 minutes. Dry and enjoy, or shake dry and store for later.

5. Sprinkle the Slices with Ascorbic or Citric Acid Powder

You’ve probably seen packaged sliced apples at your local supermarket, shockingly without a single brown spot. It’s because they’re typically treated with ascorbic acid, aka vitamin C. You can buy citric acid powder or ascorbic acid powder online or at specialty grocers like Trader Joe’s to do the same at home. A popular brand to search for is Ball’s Fruit-Fresh Produce Protector.

1. Wash and slice the apple.
2. Sprinkle the powder onto the slices.
3. Eat within 8 hours. 

6. Hold the Slices Together with a Rubber Band

Try this trick whenever you’re taking a sliced apple on the go. It protects the slices from air exposure. All you need is a knife and a thick, tight rubber band. (You can try substituting a rubber band for plastic wrap if you can’t find one.)

1. Wash and slice the apple as you normally would. Don’t throw out the core.
2. Reassemble the apple around the core.
3. Wrap the rubber band around the apple to hold the slices in place. Place it in a bag or food storage container, then toss it in your purse, lunchbox or fridge for later.

Does salt prevent apples from browning?

Why does soaking apples in salt prevent browning?

How do you keep apples from turning brown for a day?

What are 3 ways you can prevent your apples from browning?