. Search supermarkets, farmers markets, and local fruit stands. Look for avocados that are firm, unblemished, and uniformly brown. Review these qualities to determine whether an avocado is ripe:   Check the color and appearance: Choose avocados without dark blemishes or deep indentations on the skin. California Hass avocados ripen into a dark green or black shade; if they are green at all, they probably aren't ripe. Florida avocados on the other hand, have lighter-green skin with a yellowish tone, even when they are ripe.   Feel the avocados for ripeness: Gently squeeze the avocado to test its firmness. Don't squeeze very hard with your fingertips, or you'll risk bruising the fruit. A ripe avocado is soft, but it gives in to the pressure of your thumb and other fingers. Under-ripe avocados will be firm and hard; overripe avocados will be mushy to the touch, and often unevenly so.   Check the spot where the stem meets the fruit: Use your fingernail to pick away the circular remainder of the stem. This should reveal a small hole in the skin through which you can note the color of the avocado. If the "meat" is green, it's either ripe or ripening. If the inside of the avocado looks brown, black, or any other color, it's either overripe or moldy. Purchase unripe, firm avocados if you plan on using them in a few days. Store unripe avocados in a paper bag at room temperature between 65 and 75 degrees Fahrenheit (18.33 and 23.88 degrees Celsius) for up to 5 days or until they are ripe. If you want to slow the ripening process, store your avocados in a refrigerator. Only ripe or soft avocados should be refrigerated. Ripe fruit can be refrigerated until it is eaten, and should last for at least two more days. The citric acid adds a tangy flavor, but its primary function is actually to preserve the avocado butter so that it will last longer. The citric acid also prevents the avocado butter from oxidizing and turning brown. If you don't add lemon juice, the avocado butter will begin to go brown within hours of preparation.  If you don't have access to lemons, you can use any concentrated citrus juice: lime, orange, grapefruit, etc. Generally, the more sour the fruit, the more citric acid it contains. You could even use pre-bottled lemon or lime juice. Avoid using citrus juice that has been sweetened, pasteurized, or infused with chemical additives. Only use citrus concentrate. You can also use margarine, a butter substitute, or 1/4 cup olive oil. Lukewarm or room-temperature butter is much softer and more spreadable than cold butter. Because room temperature butter is softer, it's much easier to mix into avocado butter. If you have butter stored in the fridge, move it to room temperature and let it "thaw" before you use it. If you don't want to use butter, you can simply mash up the avocado with all of the other ingredients. Your butter-less "avocado butter" will not have quite the same texture as its buttery counterpart, but you'll be able to use it in all of the same situations. The crux of the recipe is the avocado, the butter, and the citric acid – so everything else that you add is purely a matter of taste. Try adding one clove of minced garlic, one tablespoon of fresh-chopped cilantro, two teaspoons of cumin, and salt and pepper to taste. Feel free to use fewer seasonings for a simpler avocado butter, or more complex seasonings for a spicier butter. Try various seasoning combinations to figure out what you prefer.
Acquire two small, ripe avocados Buy ripe, ready-to-eat avocados if you plan to make avocado butter immediately. Use one tablespoon of fresh-squeezed lemon juice. Use four tablespoons of room-temperature butter. Choose your seasonings.