Once opened, Cheese (hard such as cheddar, swiss, block parmesan) keeps about 3–4 weeks in the fridge. Unopened, it keeps about 6 months.
3–4 weeks opened in the fridge, against 6 months sealed in the fridge. Green is what this situation leaves you; husk is what it spends.
| Situation | Keeps for |
|---|---|
| Unopened · fridge | 6 months |
| Opened · fridge | 3–4 weeks |
| Freezer | 6 months |
Air and warmth are what shorten an opened item's life — the right container buys back the days the packaging gives up once the seal's broken.
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About 3–4 weeks refrigerated at 40°F (4°C) or below, according to USDA FoodKeeper v128. Refrigerate it once it's open.
Yes — keep Cheese (hard such as cheddar, swiss, block parmesan) at 40°F (4°C) or below once it's open. Refrigerate at 40°F (4°C) or below.
Look for: Sour or off smell; Mould or fuzzy spots; Curdled, slimy, lumpy, or separated texture; Yellowing or other discoloration. Those are the general signs for dairy & eggs — USDA FoodKeeper v128 publishes no spoilage note for Cheese (hard such as cheddar, swiss, block parmesan) specifically. Never taste something to test it — when in doubt, throw it out.
Yes — USDA FoodKeeper v128 gives about 6 months in the freezer at 0°F (−18°C). Frozen food stays safe indefinitely; that window is about quality, not safety.