Build 42 Food Preservation — Freezer Math, Jarring, Drying Racks, and the Winter Pantry

Build 42 does not give you one universal preservation machine — it gives you several narrow lanes, and the winter wins or loses on matching each harvest to the lane its inputs can afford. The four routes are the freezer (bulk), preserved jars (selected crops), drying racks (named herbs and grain), and the butter churn (surplus dairy). This guide gives the exact numbers for each and a decision framework for your fuel situation. Facts cross-checked against PZwiki's Food, Jar, and drying-rack pages and stable 42.20.0 on 2026-08-05.

The four preservation lanes

Freezer: the numbers

• A powered fridge slows spoilage ~5×; a freezer ~25×; a fully frozen item stops decaying entirely while frozen.
• Freezing is a generator decision: fridges and freezers on generator power draw 0.008–0.013 L/h — sustainable only with real fuel income. Full math in the generator guide.
• Without power, a fridge is just furniture — plan the generator before the water dies.
• Practical rule: keep cold slots for meat, cooked meals, and raw perishables you will actually need later. Shelf-stable items (canned, dried herbs) do not belong in the freezer.

Jarring: the small-batch crop reserve

The verified Make Jar of Preserved Food recipe on 42.20:

1 jar + 1 lid + 6 units of a preservable crop + 2.0 vinegar + 1 salt or seasoning salt + 0.5 water

Preservable foods: bell peppers, broccoli, cabbage, carrots, eggplant, leeks, potatoes, radishes, tomatoes, and fish roe. Vinegar is loot-only — every jar spends a resource the recipe itself cannot replace.

• After jarring, the food must be cooked at a heat source or it rots at normal speed (no bottle-cap sealing).
• Shelf life: ~60 days fresh + 30 stale. Opening returns the jar and food; the lid is consumed.
• Jars can be looted or made via glassmaking (Glass Jar at Glassmaking 5) — see the glass chain.
• If vinegar or lids are scarce, skip jars entirely and lean on the freezer and racks.

Drying racks: named herbs and the flour chain

Plant drying racks are a separate lane, not a generic answer for every perishable:

• Small plant drying rack handles named plants: Black Sage, Comfrey, Common Mallow, Ginseng, Plantain, Wild Garlic, Basil, and similar — their dried forms keep medical or food uses without competing for freezer space.
• Large plant drying rack handles grain and large crops: wheat sheaves, barley, corn, flax, hemp, rye, sunflower heads, and tobacco — input 1–20 units, roughly two in-game days per batch.
• Build cost (Carpentry 1): 6 long sticks, 8 units of twine, 2 nails, a hammer, and a saw.
• Start drying while the harvest is fresh, then route the dried grain into the flour chain rather than expecting a ready-to-eat meal.

Butter: absorbing surplus dairy

If livestock out-produces what your cold storage can hold, churn (cow or sheep milk, ~5 units per batch) into butter, then keep it cold if its tooltip shows freshness. Butter is a compact, high-value packaged ingredient that rides out winter better than raw milk.

Decision framework: what to do depends on your fuel

Stage jars, lids, vinegar, salt, and fuel before planting the next field — the winter pantry works when the bottleneck is decided before the harvest arrives. Pair this with the cooking guide for pot meals and the farming guide for the harvest side.

Verified on 42.20 · Last checked 2026-08-05

Freezer/fridge factors, the jar recipe and shelf life, drying-rack inputs, and churn requirements come from PZwiki's Food, Jar, and drying-rack pages (42.18-era stamps) plus current B42 references, cross-checked against stable 42.20.0 (July 29, 2026). Exact drying times and butter freshness windows are community-reported — re-verify after any patch.