Perfectly Preserved Podcast Ep. 3 - Acid and Canning Explained
Acid is a key element in canning. Anna and Jenny dive deep in this episode to explain exactly why acid is so important in safe home canning practices.
All foods have an acid value. Lemons are highly acidic, for example, and area about a 2.2 on the pH scale. Veggies like green beans are around 6.6. Water is about a 7. Recipes that are safe for water bath canning are 4.6 or MORE acid, which is a LOWER number (a little confusing, I know!). That means that all water bath canning recipes are somewhere between a 2 to 4.6 in acid value. If a recipe is MORE alkaline/LESS acid/HIGHER number, that means the MUST be pressure canned.
Water bath canning is done at the temperature of boiling water. That heat coupled with the acid present in a high acid water bath canning recipe makes the environment inside the jar of preserves inhospitable to spoilers that could make us sick. That means that a jar of raspberry jam (very high in acid!) would NEVER grow the botulism toxin, which requires a LOW acid environment (among other things) to survive. You simply do not have to worry about food poisoning when you water bath can water bath canning recipes- because of ACID!