Storing the harvest: potatoes, root vegetables, apples

Storage vegetables and keeping apples are living plant parts. They use up their stored reserves – mainly sugar and starch – and give off heat, carbon dioxide and moisture in the process. This is called respiration. The warmer it is, the faster it runs and the faster the produce ages. So cool temperatures slow down not only rot caused by fungi and bacteria but also the ageing of the produce itself.

Darkness matters above all for potatoes. In light they form green chlorophyll and at the same time more solanine, a natural defence substance that can cause stomach upsets in larger amounts. The green itself is harmless, but it shows that more solanine has formed too.

Apples and some other fruits give off ethylene, a plant gas that triggers ripening. If apples are stored next to potatoes or cabbage, these can sprout or wilt faster. So apples are stored separately, ideally in a room of their own or at least in their own covered crate.

The most important step happens before storing: sorting. Only undamaged, healthy items go into store. Every bruise, every spade cut and every broken skin is an open door for rot. Damaged items are eaten first. Potatoes are not washed; let clinging soil dry briefly instead. For carrots and beetroot, twist the leaves off instead of cutting them close.

Each kind of vegetable likes slightly different air. Root vegetables such as carrots and beetroot wilt quickly in dry air and keep better in crates of slightly damp sand. Onions and garlic, on the other hand, need dry, airy storage, otherwise they go mouldy or sprout. Potatoes lie in the dark in crates with ventilation slots, apples side by side in shallow trays so they do not press on each other.

A thermometer in the storage room shows whether it is really cool. Modern cellars with heating are often too warm; old unheated cellars, garages or sheds are often better – as long as it does not freeze there, because frozen storage vegetables turn mushy.

Green patches and sprouts on potatoes contain more solanine. Cut them away generously; do not eat heavily greened tubers or potatoes that taste bitter. This applies especially to children, because smaller amounts matter more for them.

Rotten or mouldy items are removed immediately, and the ones lying right next to them are checked carefully. With soft, mouldy produce, do not just cut out the spot – throw it away. Wash stored vegetables before eating.

Before fridges existed, many families kept their winter stores in earth cellars or in a clamp. A clamp is a shallow pit in the garden: the root vegetables are layered in it and covered with straw and soil, and the soil keeps the temperature evenly cool. It needs protection from mice and rats, for example fine wire mesh, and a place where water does not collect.

Without a garden you can still store produce: a cool stairwell, an unheated storeroom or a well-insulated box on the balcony that protects from frost. What matters is always the same: cool, dark, not frozen, suitable humidity and regular checks.

Go through the store once a week. Look for soft spots, mould, sprouts and smell. A sweet, rotten smell in the cellar is a sign that something is spoiling somewhere. Look out for signs of mice as well.

Write the variety and the date stored on every crate. Some varieties keep much longer than others; whatever starts to decline first is eaten first. In this way storage ties in with the “first in, first out” principle that applies to other supplies too.

Losses are part of it. Even with good storage, something sometimes spoils. Over the years you learn which varieties and which spot in your own home work best.