Shrimp are among the most versatile of seafoods, so it's always tempting to stock up on them when they go on sale. There's no real downside to a freezer full of shrimp, unless you forget to use them up in a timely fashion. They'll stay food safe for as long as the freezer operates, but they're only at their best for a few months.
Safety vs Quality
If you've bought frozen shrimp in their original packaging, the packaging will often have a "Use-by" or "Best before" date on it. That's the vendor's estimate of how long your shrimp will retain their best flavor and quality. Usually it will be 4 to 6 months for uncooked shrimp, or about half that for cooked. You can still eat them after that time -- they'll be safe for as long as they stay properly frozen -- but their texture will suffer, they'll begin to acquire off-flavors from the freezer, and eventually they'll succumb to freezer burn.
Freezer burn happens when part of the shrimp's surface is exposed to the dry, frigid air inside your freezer. Essentially it means that part of the surface becomes freeze-dried, leaving it tough, discolored and bad-tasting. It's not a big deal with a large roast, because you can cut off the bad part. This isn't usually an option with shrimp, so prevention is your best defense.
How to Do It
- For the best storage life, divide the frozen shrimp into meal-sized portions as soon as you get home.
- Use a vacuum-sealer, if you have one, to extract as much air as possible.
- Otherwise, use regular freezer bags but suck out as much air as you can, through a straw, before sealing.
- Over-wrapping in foil or a second freezer bag provides extra protection and longer storage life.
- Date each bag with a permanent felt marker noting the "best before" date from the original packaging, or with the date you packaged them.
For the longest storage life, keep your shrimp in a chest freezer rather than a refrigerator freezer. The relatively small freezer compartment in your fridge warms up quickly whenever you open it and takes time to return to its usual 0 degrees Fahrenheit. Chest freezers are deeper, hold more food and are opened less frequently, so they'll maintain a storage temperature more capably. They can also be set 10 to 20 degrees lower, which extends the shrimp's usable life.
Picking the Best
The longest-storing frozen shrimp are frozen into a solid block of ice. They're packed in sizes of 3 pounds or larger, for restaurant or commercial use. The ones you see in the supermarket are typically individually quick frozen (IQF) instead, either right on the boat or as soon as they're landed. Some are individually glazed in ice to act as an airtight seal and protect against freezer burn. For the longest storage life, pick shrimp with their shells on but heads off. They should be loose inside their packaging.
If retail shrimp are frozen together in an irregular lump -- as opposed to a uniform block -- that's a sign they weren't kept cold enough in storage. It means they were at least partially thawed under unknown conditions and should be avoided.
Freezing Your Own
Unless you buy right from the shrimping dock -- not an option for most people -- those "fresh" shrimp in the showcase were previously frozen. Either fresh or thawed shrimp can safely be home-frozen. Keep them ice-cold on the way home, then package and date them in airtight single-meal portions just as you would with frozen shrimp. Spread them in a single layer in the coldest part of the freezer, so they'll freeze in the shortest time possible.