Rinse the shiso leaves and pat dry with a paper towel. Cut the leafstalk (the part that connects the leaf and the stem) off.
Shred the shiso leaves and place them on the bottom half of a piece of paper towel.
Fold over the top half of the paper towel to wrap the shiso leaves.
Fold the paper towel with the shiso inside a few times, put it in a freezer bag and freeze it.
The frozen shiso leaves are hard and crunchy. They'll soften once they're thawed.
Story Behind this Recipe
Since I only use a few at a time, I thought about how to store leftover shiso leaves.
Since the leaves will be frozen, I thought shredded leaves may be easier to use, so this is how I usually store them. You can also wrap an individual leaf without shredding it with a piece of paper towel and freeze it!