To freeze whole lemons: Place the lemons in a sealable plastic bag and place them in the freezer.
To freeze lemon juice and zest: Zest the lemon and place the zest in a resealable plastic bag. Juice the lemons and place the juice in a small container or into ice cube trays (the volume of each cube in a standard tray is about 2 tablespoons). Once the ice cubes are frozen, transfer them to a resealable plastic bag.
Mark the “Use by” date. Use a permanent marker to label with a “use by” date that is 3 months in the future.
Freeze. Place the container or bag in the freezer and freeze for up to 3 to 4 months. For best results, use in 3 months.
Defrost. You can use the frozen zest without thawing. For the juice, defrost it by placing in the refrigerator overnight. To defrost a whole lemon, place it in the refrigerator overnight or microwave the lemon in 20 second bursts until it is thawed. To zest a whole frozen lemon, rinse it with warm water first, then dry it and zest it. Whole lemons become mushy after thawing, so only use the zest and juice (not slices).