Canning and preserving

In short: In canning, food is heated in clean jars so that germs are killed and a vacuum seals the jar. Jam, fruit and vegetables then keep for months.

In more detail: Food keeps through heat, acid, sugar or salt. Cleanliness and tight jars are crucial.

In detail

• Prepare jars: Rinse hot or sterilise in the oven; do not touch anything that touches the food.
• Jam: Boil fruit with gelling sugar, fill hot, turn jars upside down or close directly.
• Canning in a pot: Heat jars in a water bath at about 80–100 °C for 20 to 90 minutes depending on contents.
• Low-acid foods: Vegetables and meat need higher temperatures. Care is needed because of botulism.
• Checking: The lid must curve inward. Discard jars with mould or gas formation (küchenhygiene-und-lebensmittelinfektionen-salmonellen-und-co-vermeiden).