How to Keep Apples from Turning Brown
Cut apples brown because an enzyme in the flesh, polyphenol oxidase, reacts with oxygen the moment the cells are exposed. Slowing that reaction down takes either lowering the pH around the flesh or physically blocking air from reaching it, and some kitchen fixes work far better than others.
Steps
- 1Fill a bowl with 2 cups of cold water and stir in 2 tablespoons of lemon, lime, or orange juice.
- 2Cut the apple into slices or wedges as usual.
- 3Drop the cut pieces into the acidulated water as you go, rather than waiting until all the slices are cut.
- 4Let the slices sit in the solution for 3-5 minutes, no longer, or they start tasting sour.
- 5Drain the slices in a colander and pat them dry with a paper towel before serving or packing.
- 6For a milder flavor trade-off, dissolve 1/4 teaspoon of salt in 2 cups of water instead of using citrus juice and follow the same soak time.
Common mistakes
- Slicing all the apples before treating any of them: the first slices cut can brown in under 5 minutes if they sit exposed to air.
- Using too much lemon juice: a heavy-handed pour makes the apples taste like citrus instead of just protecting the color.
- Storing treated slices wet in a sealed container: trapped moisture makes them soggy by the next day, so pat them dry first.
- Skipping the soak and relying only on plastic wrap pressed to the cut surface: it slows browning somewhat but doesn't stop it the way an acid bath does.
Equipment
- Mixing bowl
- Paring knife or apple slicer
- Colander
- Paper towels
FAQ
Why do apples turn brown when cut but not when whole?
The peel and outer cell walls keep the polyphenol oxidase enzyme separated from oxygen. Cutting ruptures the cells and lets the two meet, triggering the browning reaction within minutes.
Does salt water work as well as lemon juice?
It slows browning noticeably but not as completely as an acid soak, since salt water doesn't lower the pH the way citrus juice does. It's a good option when a citrus taste isn't wanted.
How long do treated apple slices stay fresh-looking?
Slices soaked in acidulated water and then dried typically stay pale for 6-8 hours at room temperature and up to 24 hours refrigerated in an airtight container.
Can honey water keep apples from browning?
Yes, a solution of 1 tablespoon honey dissolved in 1 cup of water works almost as well as citrus juice, since honey contains natural antioxidant compounds that interfere with the enzyme.
Do all apple varieties brown at the same rate?
No. Varieties like Granny Smith and Honeycrisp have lower polyphenol oxidase activity and brown more slowly, while Golden Delicious and Fuji tend to brown faster once cut.
Need exact temperatures or timing? Check our Time & Temperature Guide →