The bumpy alligator skin of a typical Hass avocado starts out dark green and ripens to eggplant color, says licensed nutritionist Monica Reinagel, author of Nutrition Diva’s Secrets for a Healthy Diet. This hue is key. If you’re looking for an avocado you can eat tonight, you want one with dark green to purple-y or brown skin. If you’re looking to stock your kitchen with a few fruits you can eat later, shop for one that’s mid to dark green. Then make sure there aren’t any deep scratches or scrapes on the outside that could affect the fruit inside.

If you spot larger, smoother, leather-y avocados that are bright Kelly green, those are the Florida variety. “These have less fat and more water, so they’re lower in calories but also not quite as creamy. Unless a recipe specifically says Florida avocado, I always assume to use ‘Hass,’” Reinagel says. The color also stays more or less the same as it ripens, so use the steps below to pick the perfect Florida fruit.

Press down on the avocado with your thumb. A good one will have a little give rather than feeling like you’re pressing against a wall. “Ripeness is best determined by pressure because softening of the fruit can happen at any rate, independent of the color,” says Emiliano Escobedo, executive director of the Hass Avocado Board. But don’t make the mistake of thinking more give equals more goodness. If your thumbprint stays indented or the flesh feels squishy, skip it, as it’s likely overripe, Escobedo adds.

Here’s a trick that’s circulating around the Internet: If you pop the little button stem off the top end of the avocado, it’ll tell you if the avocado is a good candidate. If the skin under it is green, you’re good to go. If the skin under it is brown, it’s past its prime. But there’s a huge caveat: “When you pop off the stem, you allow air to enter into the avocado, which can cause premature oxidation and browning. So leave those stems on until you’re ready to eat the avocado,” Reinagel says. Removing the stem at the store can also create an opportunity for the avocado to rot without ripening, says Mary Dawn Wright executive research chef of the Sabra Dipping Company.