Pressure Canning for Low-Acid Vegetables: A Guide for Australian Gardeners

Why Pressure Canning is RequiredWater bath canning reaches only 100°C — the boiling point of water. Clostridium botulinum spores survive this temperature in low-acid foods (pH above 4.6) and can germinate in the sealed, anaerobic jar to produce the botulism toxin. Pressure canning reaches 116–121°C — the temperature required to kill all botulism spores in low-acid foods within a practical processing time. There is no safe shortcut: low-acid foods must be pressure canned or kept refrigera…