Pickles

Unopened shelf-stable pickles keep 1–2 years in the pantry. Once opened, refrigerate them — they keep about 1–2 years in the fridge, which is an unusually generous window.

Keep them submerged in the brine. This is the only technique that matters. Pickles above the liquid line dry out, discolor, and mold, while the same pickles submerged stay good for months. If the brine is running low, do not top it up with plain water — that dilutes the acid.

Always use a clean fork rather than fingers.

Refrigerator pickles — the fresh, unprocessed kind, sold chilled — are a different product with a shorter life, usually about 2 months, and they must stay cold.

Pickles do not freeze; they turn limp and hollow.

There are two quite different things called pickles, made by opposite methods.

Vinegar pickles, which are most of what is sold, are preserved by immersion in acetic acid — a pH around 3.2–3.5, far below the 4.6 threshold for pathogen growth — and then heat-processed. Nothing much can grow in them, which is why an opened jar lasts a year in a fridge.

Fermented pickles, the traditional barrel-cured kind, are preserved by lactic acid bacteria converting the cucumbers' sugars into acid in a salt brine. The bacteria are the preservative. These are usually sold refrigerated, are often cloudy, and are alive in a way vinegar pickles are not.

That distinction explains a common confusion: cloudy brine is normal in fermented pickles and a warning sign in vinegar pickles. In a fermented jar it is lactic acid bacteria doing their job; in a shelf-stable vinegar jar it suggests contamination.

The white sediment sometimes seen in either is usually harmless yeast or calcium salts.

Real problems: a bulging lid, which indicates gas production; mold on the surface; brine that has turned slimy or ropy; and a soft, mushy texture throughout, which means pectin-degrading enzymes have broken the cucumber down.

Discard the whole jar if the lid is domed or the brine is ropy.