Food-safety guidance on handling, cooking, storage, spoilage signs and when food should be discarded.
The clearest signs of a spoiled sweet potato are mold, wet sunken soft spots, leaking fluid, a fermented or rotten odor and decay extending into the flesh. Mild wrinkling usually reflects moisture loss and declining quality rather than spoilage by itself. Chilling injury can also produce internal browning, shriveling and greater susceptibility to fungal decay.
When cooking oil starts to smoke, it has reached a temperature at which some of its components are breaking down and producing volatile compounds. It does not become instantly poisonous, but it is outside a sensible cooking range: lower or remove the heat, ventilate, and do not keep driving the temperature upward.
Normal frying bubbles come from water in food turning rapidly into steam. Surface water or ice can vaporize abruptly and throw hot oil droplets from the pan. Persistent foam is different: starch, proteins, batter crumbs and degradation products in reused oil can stabilize bubbles and create a layer that does not collapse as quickly.
Dry rice does not suddenly become unsafe when a best-by date passes, but quality does decline. Under ordinary pantry conditions, tightly stored white rice commonly keeps good quality for about 1–2 years. Brown rice has a much shorter window, around 6 months, because it retains oil-rich bran and germ that can oxidize and turn rancid.
Yes, both Serrano ham and cooked ham can be frozen. The tradeoff is quality: USDA lists about 1 month of freezer quality for cut dry-cured Serrano/Parma/prosciutto-style ham, while opened or sliced cooked ham is generally listed at 1–2 months. Portion tightly, remove excess air and thaw in the refrigerator.
Opened dry pasta does not become perishable in a few days. Its low moisture makes it shelf-stable, and about one year is a useful quality reference when it is tightly closed and kept cool and dry. Discard it for insects, mold, moisture or abnormal odors rather than because the package has merely been open for a while.
Localized brown patches inside an avocado often come from bruising, overripeness or internal tissue damage and do not automatically make the whole fruit unsafe. If the surrounding flesh looks normal, feels creamy rather than slimy and smells fresh, trim the damaged area. Mold, fermented or rancid odors and widespread breakdown are reasons to discard it.
Opened cheese should go back into the refrigerator protected from drying and contamination. Hard cheese keeps best when wrapped without trapping heavy condensation; soft and fresh cheese should stay covered and be used sooner. The cheese type matters as much as the date you opened it.
Yes, cooked shrimp can be frozen. Freeze them while they are still safely handled, package them with little air, keep the freezer at 0°F (-18°C) or below, and thaw in the refrigerator when possible. Freezing cannot correct seafood that already spent too long warm.
Yes, you can eat pasta the next day if it was refrigerated soon after cooking and kept cold. The risk is driven more by time spent warm than by the fact that 24 hours have passed. For properly chilled leftovers, USDA uses a 3-to-4-day refrigerator window.
Yes. Freeze fresh salmon promptly, remove as much air as possible and keep the freezer at 0°F/-18°C or colder. USDA quality guidance for raw frozen fish is roughly 3-8 months. If the salmon will be eaten raw, use the specific parasite-destruction rules that apply to that preparation rather than assuming ordinary storage time is enough.
A whole bone-in cured ham does not suddenly expire on one fixed day after the first slice. For best eating quality, plan to finish it in roughly 3-6 weeks; specialist ham retailers sometimes give 6-8 weeks under good conditions. Heat, light and an uncovered cut surface shorten that window.