Your guacamole is only that good as your avocado. Picking the right avocado that is perfectly ripe and firm is the key to making the best guacamole. While buying avocados in the store, pick the ones that still has the stem attached. If you pick the ones that has the stem removed, you’ll likely end up with avocado that has brown spots in the middle. If you remove stem (when ready to make guac), it should be green underneath. And if it’s brown underneath, it’s over ripe. To see if avocado is ripe, gently press on one end, it should have a little bit of give to it. But it shouldn’t be too soft and mushy. If it doesn’t yield at all, then it’s not ripe and ready.  If it doesn’t yield, give it a couple of days. Thumb rule to pick the right avocado is – Still has the stem on, Should slightly yield to it, Should be firm and not mushy.