It's an art, not a science—but there are some tricks
There are few feelings of disappointment quite like that of slicing open an avocado only to realize that it's not yet fully ripe or—even worse—gone totally black and rotten. So how can you tell if an avocado is ripe before you've cut into it? There are a few signs your avocado is ripe and ready to eat, and once you know what to look for, you'll improve your accuracy immensely when it comes time to choose a ripe avocado at the grocery store. I should note here that avocados are fickle fruit, and these tips to tell if your avocado is ready to eat aren't foolproof. But knowing they'll definitely make it easier to know when an avocado is worth the $2.50 at the grocery store versus when it's time to just give up.
So here are the three things you should look for when trying to find the perfect avocado.
Note the Color
The most obvious indicator of an avocado's ripeness, especially from far away, is its color. If the avocado is bright green and glossy, it's unripe. You're looking for an avocado that's darker in color—almost a hunter green with a more matte finish. But if it's a deep, dark shade of black, or the fruit has brown, flaky spots, it's overripe—and the inside of the avocado is probably speckled with black, too.
Color alone, however, can't tell you if an avocado is ripe or not. Sometimes, an avocado that looks underripe, with green specks coming through the darker skin, is actually just right. That's why you need to pick up the avocado and gently squeeze it. As the experts from the Haas Avocado Board explain, "If the avocado does not yield to gentle pressure it is considered still 'firm' and will be ripe in a couple of days." The avocado shouldn't feel totally mushy, though; the fruit should still have a bit of structure. Be careful not to squeeze too hard, though, because if you do, you will bruise the fruit, and that doesn't help anybody.
Check the Stem
If you've got an avocado in your hands that feels soft enough but not too soft, looks dark enough without seeming rotten—and you're still not totally sure if it's ripe or not, it's time to check the stem. Erica, the Seattle-based food and gardening blogger behind Northwest Edible Life, told The Kitchn that the best way to know if an avocado is ripe or not is to take the little stem off the top of the fruit. "If it comes away easily and you find green underneath, you've got a good avocado that's ripe and ready to eat." The stem of an overripe avocado will also come off easily, but it'll look black underneath. Meanwhile, the stem of an underripe avocado will be a challenge to wiggle off.
It'll take some practice to learn how to pick the right avocado, but at least you'll be able to make a lot of guacamole until you perfect your technique. If you're still in doubt about whether your avocado is ripe enough, you should err on the side of buying an underripe fruit. That way, you can ripen the avocado at home instead of having to throw away an overripe one, which is really the ultimate tragedy.