Since a half cup of buttermilk is the smallest unit of measurement I use, I freeze multiples of half cups. I pour the buttermilk into snack size zip top bags and remove as much air as I can. I then put the bags of buttermilk into a quart size, zip-top freezer bag, write on the bag how many snack bags of buttermilk it contains, date and freeze. This way I can take out as many bags of buttermilk as a recipe calls for. These thaw easily under running water, or cut the bags open and put in a microwave-safe bowl and microwave in 30-second increments at 50% power until thawed.
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