Haddock

Haddock keeps 1–3 days refrigerated and 6–8 months frozen as a lean whitefish. Store it dry, covered, and over ice in the coldest part of the fridge.

Haddock is a close relative of cod and stores much the same way, with one difference: its flesh is softer and finer-grained, so it deteriorates in texture slightly faster. Treat the short end of the 1–3 day window as the realistic one.

Smoked haddock — finnan haddie — is a different product with different rules. Cold-smoking is a mild preservation, not a cooking step, so smoked haddock still needs refrigeration and typically keeps one to two weeks unopened, or the package date if sooner. Dyed bright-yellow smoked haddock is colored for tradition and tells you nothing about age.

Fresh haddock freezes well. Wrap airtight, and freeze on the day of purchase rather than at the end of the refrigerator window.

Haddock is very lean, so oxidative rancidity is a minor factor and the freezer window runs long at 6–8 months. Its failure mode is structural and bacterial rather than chemical.

The flesh is finer and softer than cod's, with more delicate connective tissue between the muscle blocks. As that tissue breaks down the fillet loses its spring, turns from pearly translucent to flat white, and begins to weep a milky liquid. Press it: fresh haddock rebounds, aging haddock holds the dent.

As a North Atlantic marine fish, haddock carries the usual load of trimethylamine oxide, which bacteria convert to trimethylamine as it ages. That is the sharp ammoniac smell, and in haddock it arrives reasonably promptly — the smell test is more reliable here than it is for freshwater species like tilapia.

One point specific to smoked haddock: the smoke and salt slow bacterial growth, but cold-smoked fish has not been cooked. It is a ready-to-eat refrigerated product, which puts it in the same Listeria risk category as cold-smoked salmon, and the same caution applies for pregnant and immunocompromised people.