In order to freeze fresh mint leaves, freeze them in a single layer on a pan and then transfer the leaves to an airtight container or create a paste with oil and freeze in ice cube trays. The leaves do not need to be thawed before use.
Before freezing mint leaves, or other herbs, thoroughly wash and pat dry the leaves to avoid crystallization during freezing. When using the pan method, place the leaves on the pan in a single layer and place in the freezer. Once the leaves are frozen, place them in an air-tight container, pushing out all of the air before sealing.
Freezer bags are one possible method, as they are thicker than regular plastic bags. Consider using a vacuum seal bag to remove all of the air before sealing.
Plastic containers that are freezer safe are another possible method. These containers feature a label on the bottom indicating that they are safe for use in the freezer.
Glass canning jars are another freezer storage method.
As an alternative method, use a blender to blend 1/3 cup of oil with 2 cups of herbs. Then, freeze the paste in covered ice cube trays or an airtight container.
Make sure to label the storage container with the freeze date and type of herb.