With harvest season upon us, the Centers for Disease Control and Prevention (CDC) recently issued important information, through Foodsafety.gov, about the dangers of botulism and the steps home canners should take to prevent the proliferation of toxins in their canned goods. Armed with this knowledge, home cooks will be able to ensure that the foods they put away for the winter months are safe for consumption.
Botulism is an illness caused by the soil-based Clostridium botulinum germ. When vegetables containing the germ are improperly canned, it can grow and create a tasteless, odorless toxin that can cause deadly nerve damage and paralysis if consumed. Low-acid vegetables with a pH level greater than 4.6 are especially likely to cause botulism, since they aren’t acidic enough to inhibit the growth of the botulinum bacteria. These vegetables include: asparagus, green beans, beets, corn, potatoes, and some tomatoes. Tomatoes, especially, require supplemental citric acid or lemon juice in order to be safely canned. Other low-acid foods that may cause botulism if improperly canned are all meats, fish and seafood, and figs.
The symptoms of foodborne botulism include double vision, blurred vision, dropping eyelids, slurred speech, dry mouth, a thick-feeling tongue, difficulty swallowing, and muscle weakness. People exhibiting these symptoms should seek emergency medical treatment immediately.
If you wish to can, preserve, or ferment your own produce, you should strictly follow the canning techniques provided by the USDA and / or state and county extension services. Proper canning techniques include using pressure canning only for low-acid foods (not boiling water canners). After canning, jars that have been improperly canned and may be contaminated with the botulism toxin may appear to be bulging, swollen, cracked, leaking, or otherwise damaged. If the food inside is discolored, moldy, rancid, or if the container spurts liquid or foam when opened, the contents have possibly been contaminated and should be disposed of immediately without tasting. Any spills should be promptly wiped up with a bleach solution (.25 cup bleach per 2 cups water).
