How to properly store avocados and slow down browning

• If you don't plan on eating them right away, place ripe avocados in the fridge to extend their shelf life.
• Prevent opened avocados from browning by spritzing with acid and covering tightly in plastic wrap.
• You can freeze avocados, but need to work quickly to reduce oxidation.

Opening a perfectly ripe avocado can feel a little like winning the lottery. Almost as often as we cut into one that's textbook pale-green and creamy, we unearth fruit that's chalky and hard or going brown - all the more dispiriting because avocados aren't cheap.

Of course, choosing an avocado is only half the battle - once cut, its half-life is short. To help you make the most of the ephemeral green fruit, we consulted experts for tips on storing ripe, unripe, and cut avocados.

How to tell if an avocado is ripe

Like tomatoes and bananas, avocados are climacteric fruits, meaning they continue to ripen after harvest, says Guy Crosby, PhD, science editor for America's Test Kitchen and adjunct professor at the Harvard School of Public Health. "At least they are forgiving in that way. If you buy them when they're not quite ripe, they'll ripen eventually."

But when? Crosby points to the four stages of ripeness put forth by the Hass Avocado Board as a guide, noting that feel is a more reliable indicator of ripeness than color.

Quick tip: When testing for ripeness, squeeze gently in the palm of your hand, rather than with your fingers, which can bruise the fruit.

• Unripe: Bright green and hard to the touch, these firm avocados will take four to five days to ripen.

• Breaking: Almost-ripe avocados, varying in color and slightly softer, are one to two days from ripe.

• Ripe: Ready-to-eat ones will be firm, but yield to gentle pressure, "similar to a ripe peach," says chef and culinary consultant Jason Hernandez.

• Overripe: Just as it sounds, these have mushy skin, possibly with deep indentations, and brownish fruit that smells like squash. It's not going to harm you, but it won't be pleasant to eat.

The best way to store an avocado

Avocado storage varies based on its ripeness level and when you plan on eating it. There's no need to refrigerate unless you want to slow down the ripening process. On the flip side, you can speed the process up by a day or two if by putting avocados in a brown paper bag with a fellow ethylene-emitting fruit, like a banana.

What about those common storage myths? Tips abound on how to squeeze a few more precious hours out of a ripe avocado, but with little success. Contrary to popular belief, keeping the pit in your avocado or adding it to your guac won't prevent browning except for right underneath it, Hernandez says. Instead, cover the bowl with plastic wrap, gently pressing it onto the surface to reduce browning.

The same goes with spraying the exposed surface with water, milk, or oil. This creates a temporary barrier to air, but won't make much of a difference long term - and can change the avocado's texture.

How to store avocados

• Unripe: If you're planning to use an unripe avocado in four or five days, store it on the counter. You can also store firm, uncut avocados in the refrigerator for up to two weeks. They will continue to ripen, albeit at a slower rate.
• Ripe: Don't store it - eat it! If you're not planning to eat a ripe avocado right away, though, you can refrigerate it to slow the ripening process, generally for two to three days.
• Cut avocado: "Oxygen is the enemy of the cut avocado," turning the flesh brown or black and mushy, says Dr. Crosby. Mitigate that by spritzing the flesh with lemon or lime juice or even vinegar to lower the pH, which will slow down the rate at which the enzyme responsible for browning (known as polyphenol oxidase) reacts with air. You can also tightly wrap the cut avocado in plastic wrap, making sure the plastic is in contact with the fruit's surface

Can you freeze avocados?

If you're looking to store avocados long term, yes, you can freeze them. It helps to know ahead of time how you plan to use the defrosted avocado - for example, sliced or smashed, says Hernandez. "Either way," he says, "work quickly and have lemon juice ready to reduce oxidation."

How to freeze avocados

• To freeze avocado halves: Cut the avocado in half, peel, and remove the pit. Brush the entire surface with lemon juice and wrap individually and tightly in plastic wrap that clings to the fruit. Transfer to a zip-top bag, remove as much air as possible, and freeze. This technique is best if you plan on slicing the avocado.
• To freeze smashed avocado: If saving for guacs, dips, dressings, and cold sauces, scoop the halves into a bowl, drizzle with lemon juice, and mash to your liking. Portion into freezer bags sized so you don't have a lot of extra air space, remove as much air as you can, and seal tightly. Tip: Flattening the mash to half-inch thickness shortens thawing time.
• To thaw: Place the frozen avocado in the fridge or at a cool room temperature and let thaw for 15 to 30 minutes before using.

Insider's takeaway

The best way to store an avocado depends on its ripeness, whether it's been opened, and how long you plan on saving it for. One thing they all have in common, however? As little exposure to air as possible since oxidization causes the dreaded browning effect.