Seafood questions come with photos: orange liquid in a salmon pack, grey salmon, green growth on frozen tilapia, shrimp that taste off. Underneath most of them is the cold chain. Here is what we look for, and what to specify when buying seafood by the case or pallet.
Salmon purge and color
Purge is the liquid fish releases in the package. Some purge is normal, and salmon purge is often orange or red from the flesh pigment. A loose or broken vacuum seal is the bigger concern, because the fish has been exposed to air.
Color depends on species and diet. Sockeye is naturally deep red; other species are paler. Fish frozen quickly and kept hard-frozen keeps color best. Thaw-refreeze cycles and long storage without good glazing fade it.
Grey on salmon is often the bloodline, the darker, oily muscle under the skin. It is normal. Off odors, a slimy surface or a sour smell are not.
When frozen fish is still safe
USDA FSIS guidance is clear on the basics:
- Food kept frozen at 0°F stays safe indefinitely; quality is what declines.
- Meat and fish thawed in the refrigerator can be refrozen, with some quality loss.
- Perishable food left out more than 2 hours, or 1 hour when it is above 90°F, should be discarded.
Mold or unusual growth on frozen fish means the package warmed up at some point. Throw it out. For raw uses such as poke or sushi, buy fish sold and handled for raw use, keep it frozen until needed, and thaw it in the refrigerator.
Shrimp counts and specs
Shrimp are sold by count per pound. 21/25 means 21 to 25 shrimp per pound; lower numbers mean bigger shrimp. When you order, also specify:
- Raw or cooked
- Shell-on or peeled, and deveined or not
- Tail-on or tail-off
- Glaze and net weight
- Whether you want shrimp without added moisture-retaining treatments, which some buyers say change taste and texture
Tail-off peeled shrimp are the usual choice for soups, pastas and cocktails. Our seafood board lists counts and packs, including 21/25 shrimp.
Receiving seafood
- Check product temperature: frozen at 0°F or below, fresh at 40°F or below.
- Look for thaw signs: ice crystals inside bags, frozen-together blocks, stained boxes.
- Check vacuum seals and glaze.
- Smell a sample: clean and briny is right; sour or ammonia is not.
- Note problems on the bill of lading before signing.
What to ask
Ask for species, catch or farm method, and freeze date. For tilapia, salmon and shrimp programs, consistent specs mean consistent yields and fewer complaints.
A tight cold chain from the plant to your cooler is the best quality guarantee in seafood.