can botulism grow without moisture? - Ask Extension
I recently purchased a vacuum sealer that seals mason jars. I wanted to use it to vacuum seal the fruits and vegetables that I dehydrate, Particularly...
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can botulism grow without moisture? #428656
Asked September 26, 2017, 12:41 AM EDT
I recently purchased a vacuum sealer that seals mason jars. I wanted to use it to vacuum seal the fruits and vegetables that I dehydrate, Particularly tomatoes but also onions and garlic. I know Botulism grows in a zero oxygen environment, but is there a risk of it growing if there is no or low moisture?
Washington County Oregon
Expert Response
Due to their low water activity, dehydrated foods and foods high in salt and/or sugar do not support growth of C. botulinum. Vegetables should be dried until they are brittle or "crisp." Some vegetables actually shatter if hit with a hammer. At this stage, they should contain about 10 percent moisture, which is too low for botulism growth.
Vacuum sealing is a good method of preventing dehydrated, low acid foods from absorbing enough moisture from the air to support mold growth or other types of spoilage, including botulism.
Botulism is not a concern in higher acid foods, such as fruits.
