Canning breads or cake.

Asked February 28, 2020, 2:36 AM EST

When searching online for info on canning cakes at home experts agree that oven canning, particularly in a low acid product like a cake, is bad news bears. But what if you water bath can it? or pressure can it? I specifically want to can a sourdough batter which will have a ph much lower than 4.6. Other than it not being an approved recipe what could go wrong? One thing I can think of is the batter is going to puff up significantly during boiling and then collapse during cool down making calculating head space difficult. The composition of the atmosphere in the jar would also have a significant amount of CO2 from the leavening which, I'm guessing, would be unusual for a canned good.

Multnomah County Oregon

1 Response

Thanks for contacting Ask an Expert.

Are you thinking about canning the starter or a bread or cake batter?

In all methods you mentioned there is risk of jar explosions.
Ball/Kerr and other reliable manufacturers have designed canning jars for moist heat conditions. "Oven canning" is a dry heat method and can cause the jars to break, so this practice is never recommended. Ball/Kerr doesn't recommend dry heat methods for canning in their jars.
The nature of starches, when heated, is to expand and thicken - at unpredictable rates. This will likely cause the lids to buckle or jars to explode in boiling water canners or pressure canners.
In a batter other ingredients (extra flour, eggs, milk, oil, etc) are low acid and would outweigh the acidity of the sourdough starter. There are no safe, tested recipes from reliable resources for canning breads and cakes.

Heating the sourdough starter will cause the proteins in the fermented flour to coagulate or set. So if you can it, the very reason you are making and using the starter in a baking recipe will be defeated because it will not be able to help your baked product rise in your recipe. All the flexibility in the gluten will no longer be stretchy.

So, your flapjacks will be "flatter" than a pancake.

Making and using this non-commercial leavening, sourdough starter, is a wonderful tradition with a unique and delicious taste. You also need to use the traditional storage and cooking/baking method, too. And, if you can cook on wood-fired heating source - well, that is just a bonus!