A cache keeps food only if the food goes in dry, the container is hard and sealed, and every layer between the food and the soil is a barrier to water and to animals. Moisture, not thieves, is the usual cause of failure, and moist or low-acid food sealed airtight and buried can grow botulinum toxin, so cache dry staples and nothing else.
Part of Hidden Food Caches
Waterproofing and preservation for a cache is the choice of food, container, liners and seals that keep stored food dry, pest-free and safe through months or years out of sight.
Dry Food, Hard Container, Layered Seals
The parent article states the principle: moisture causes mould, rust, rot and spoilage, and is the primary reason caches fail. Its answer is layers: a waterproof rigid container, additional plastic bags inside it, a desiccant, tight packing to minimise air space, and for extra protection wax on the seams. The sub-articles take each layer in turn: Container Selection, Moisture Control and Pest Prevention.
The first decision is not the container but the food. The parent article’s list of what to cache is dry staples (rice, dried beans and lentils, salt, sugar, honey, dried pasta), plus canned goods, cooking oil and spices. The rule that decides what belongs there is simple: a food in a sealed, buried container is kept cool, in the dark and without air. Those are exactly the conditions in which Clostridium botulinum makes its toxin if the food is moist enough and has not been heat-processed to destroy the spores.
What You Need
- Dry staples at the moisture levels in Grain Storage
- A rigid, sealable container and a plastic liner
- A desiccant — silica gel or baked rice, as the parent article describes
- Wax for seams — beeswax or paraffin
- A cache log kept elsewhere, as set out in Inventory and Rotation
Method: Choose, Dry, Layer, Seal
Step 1: Choose food that is safe to seal. Dry grains, pulses, salt, sugar, dried pasta and hard biscuit. Honey is shelf-stable, but it can carry botulinum spores, and I am recalling that it must never be fed to children under one year; keep it out of any cache meant for infants. Cooking oil goes rancid within a year or two, as the parent table shows; it is not a long-term cache food.
Step 2: Leave out what is risky. The following do not go into a sealed buried container:
- home-canned vegetables, meat, beans or soup that were not pressure-processed (boiling-water canning does not destroy botulinum spores in low-acid food, as Food Safety explains)
- cooked food of any kind, fresh food, and anything oiled with garlic or herbs
- food packed damp, partly dried or with visible moisture, and meat or fish that is not fully dried and salted
- any container that already shows swelling, a bulging lid or leaking
Step 3: Check the dryness. Grain must be at or below the moisture levels in the grain article before sealing; pemmican and dried meat only if made as described in Pemmican Making.
Step 4: Layer. Food in a sealed plastic liner, the liner in a rigid container with a gasket lid, desiccant at the top, the lid sealed and its seam waxed. Pack the container full so that little air remains.
Step 5: Label inside, not outside. A date and contents list goes inside the container. Nothing on the outside tells a finder what is there.
Step 6: Check on a schedule. The parent article says to check every cache every 3-6 months. Open and inspect for moisture, pests and damage, and replace anything doubtful. See Inventory and Rotation for the other side of that advice.
Common Mistakes
- Sealing food that is slightly damp. A sealed container keeps the moisture in with the food.
- Trusting a vacuum seal as a preservative. The parent article says vacuum-sealed food lasts longer; that holds for dry food. For moist, low-acid food, removing air helps the very organism that makes the toxin.
- Relying on the desiccant to dry the food. It dries the air, not the grain; see Moisture Control.
- Metal cans of unknown age in a damp hole. Rust perforates them; see Container Selection.
Safety
A swollen, gassy or off-smelling container is lethal, not just spoiled
Botulinum toxin is among the most poisonous substances known and even a very small amount can cause paralysis and death. It is not destroyed by the gentle warmth a cache or a pocket provides, and it can be present in food that looks and smells normal. Never taste food from a bulging, hissing, leaking or foul-smelling can, jar or container. Do not open it indoors or feed it to animals. Seal it again, bury it deep away from water, animals and children, and wash hands and surfaces that touched it. Pressure-can low-acid food or leave it out of the cache; see Food Safety.
What’s Next
- Learn next: Container Selection — what to put the food in
- Combine with: Emergency Caches — storage-side view of the same caches