Keep frozen for up to 1 year. Thaw in the fridge for 24–48 hours, or quick-thaw in a bowl of cold water for 2–3 hours. Once thawed, use within 2–3 days.
Learn more about optimal thawing methods
On a well-marbled cow, this is about the best and most expensive part; however, the cow needs to marbled or it will be tough.