Butter freezes well and keeps for up to four months in a freezer, according to Challenge Dairy. Butter that is fresher keeps longer, and very fresh butter potentially keeps for up to 12 months.
Butter in its original packaging, placed within heavy duty freezer storage bags tends to keep freshest when frozen at 20 to 30 degrees Fahrenheit. Despite the extended shelf life of frozen butter, slight changes in flavor and texture tend to occur the longer the butter remains frozen.
It is advisable to thaw frozen butter in the refrigerator before using it. However, frozen butter is fine for recipes that call for very cold butter.