Measure out 1 cup of buttermilk to start.
Pour the buttermilk into ice trays.
On a large freezer bag or freezer container, write how many cubes equal a cup and the date.
Continue with remaining buttermilk if you are freezing more than 1 cup.
When cubes are solid, remove from ice trays and place in the prepared freezer bag or container.
Store in the freezer for up to 3 month.
To thaw, place the desired amount of cubes in a sealed bag and submerge in hot water. You could also place the cubes in the fridge to thaw out over night.
Once thawed out whisk or stir vigorously as the buttermilk tends to separate once thawed.