Use ripe avocados (yield slightly to gentle pressure). Cut in half, remove the pit, and scoop out the flesh. For purée, mash with a fork or blend until smooth. Add 1 tablespoon of lemon or lime juice per avocado to prevent browning.
For purée (most versatile): mash the flesh with citrus juice. Pack into small freezer bags (one avocado per bag), press out air, and lay flat to freeze. Or spoon into ice cube trays, freeze solid, and transfer cubes to a bag.
For halves or slices: brush all surfaces with lemon or lime juice, wrap tightly in plastic wrap (pressing wrap directly against the flesh), place in a freezer bag, and press out air. Halves and slices will be softer than fresh when thawed and are best for spreading or mashing.
4 to 6 months.
Thaw in the refrigerator for 4 to 6 hours, or place the sealed bag in cold water for faster thawing. Use immediately after thawing as browning accelerates once thawed. Stir or mash to restore a uniform texture.