Home preserving: crunchy pickles, sauerkraut and jam without mistakes

Pickling in vinegar preserves with acid: vinegar creates an environment where bacteria can't grow. Cucumbers, tomatoes, peppers and courgettes pickled in vinegar keep for a year at room temperature.

Fermenting and brining rely on lactic acid fermentation: salt suppresses harmful bacteria while beneficial lactic bacteria turn the vegetables' sugar into lactic acid. That's how sauerkraut, brined cucumbers and pickled apples are made. They're kept cool.

Jam and preserves use sugar: a high concentration draws water away from microbes. The classic is 1 kg sugar per 1 kg fruit.

Wash jars with baking soda (not washing-up liquid — it's hard to rinse off) and check the rims for chips: a chipped jar won't seal.

Choose small, firm cucumbers with dark bumps — pickling varieties. Smooth salad cucumbers go soft. Soak the cucumbers in cold water for 3–4 hours: they take on water and stay crunchy.

In each litre jar: a dill head, 2–3 garlic cloves, a horseradish or blackcurrant leaf, 3–4 black peppercorns, a bay leaf.

This method seals cucumbers and tomatoes without processing the filled jars in a water bath.

These aren't preserves but a quick snack: they keep in the fridge for up to a week.

Brine: 1 litre water, 2 level tbsp salt. Pack cucumbers with the ends trimmed tightly into a jar or pan with dill, garlic, horseradish and blackcurrant leaves. With cold brine they're ready in 2–3 days; with hot brine in 12–24 hours. Leave at room temperature, then move to the fridge.

The key number is 2% salt by weight of cabbage: 20 g (a heaped tablespoon) per 1 kg of shredded cabbage. Less and the cabbage can go soft and sour off; more and fermentation slows and it tastes salty.

Shred the cabbage, add 1 grated carrot per 1 kg and the salt. Squeeze with your hands for 1–2 minutes until the cabbage releases juice. Pack tightly into a jar so the juice covers the cabbage completely. Leave 2–3 cm of headspace — the juice rises during fermentation.

Keep at 18–22 °C for 3–5 days. Every day, poke the cabbage to the bottom in several places with a wooden stick to release gas — otherwise it turns bitter. When fermentation calms down and the cabbage is pleasantly sour, move it somewhere cold.

The classic ratio is 1:1 by weight of fruit and sugar. Jam like this keeps in the cupboard for a year. If you want less sugar (1:0.5), keep it in the fridge or use a pectin setting agent as the pack directs.

For whole berries in syrup, cover them with sugar for 4–6 hours to release juice, then cook in 2–3 stages of 5 minutes, cooling for a few hours in between. The berries soak up syrup and don't fall apart. Skim off the foam — it collects impurities.

The most serious danger in home preserves is botulism. The bacteria live in soil and multiply without oxygen in low-acid conditions. In a sealed jar they produce a toxin with no smell or taste that can be fatal.

Vinegar pickles, sauerkraut and jam with enough sugar are unsuitable for botulism. The danger is low-acid foods sealed airtight without an industrial pressure canner.

Keep sealed jars somewhere dark and cool — 5–15 °C, a pantry or cellar. Pickles and jam keep up to a year; after that the taste declines. Sauerkraut and brined cucumbers keep at 0–5 °C, in the fridge or cellar, for up to 6 months.

Label the jars with the contents and date. After a month all jars of cucumbers look the same.

Keep an opened jar in the fridge: pickles up to 2 weeks, jam up to a month. Use a clean, dry spoon so you don't introduce mould.