Most of us are on a mission to get the most bang for our buck at the grocery store. Sometimes, this means opting for frozen rather than fresh, which often includes meat. If you enjoy fish, there’s one way you can make sure the frozen stuff is as fresh as possible.

When purchasing frozen fish, you should be on the lookout for two different labels: “frozen at sea,” and “individually quick frozen.” Both of these describe how a fish was frozen before making it to the grocery store.

The first method, frozen at sea, means exactly what it sounds like. When a fish is caught, it’s immediately filleted and frozen on the boat. Labels that have this marker are able to better retain freshness as they aren’t brought back, thawed, and processed again like options labeled as “previously frozen.”

The second method is individually quick frozen which sees fish and seafood fast-frozen in single units in a few minutes or hours. Like the FAS method, the IQF process first sees fish filleted but instead of being frozen immediately, it’s placed in a layer of water to help keep it fresh. Then, it’s frozen.