1) The baking of bread or cakes in glass canning jars.
Unsafe practice: A batter of banana bread, zucchini bread or similar cake or bread is spooned into glass canning jars and baked. After baking but while jars are still hot, a canning lid and ring are secured. As the jar cools, the air is removed from the jar and the lid is vacuum-sealed into place.
2) The sealing of butter or margarine in glass canning jars.
In both cases, an environment supportive of botulism growth is created. In order for botulism to produce its deadly neurotoxin, it needs three things: no oxygen, low acidity, and a tiny bit of moisture.
If a botulism bacteria is placed in a this environment, it begins to produce a neurotoxin, which if consumed, begins to paralyze muscles. Victims often need antitoxin drugs to deal with it; others need life support when they can no longer breathe on their own, and others succumb and die.
Improper home-canning methods are a major culprit of botulism poisoning.
Canning Rules to Live by:
- Use a recently published canning book which contains tested recipes. Do not get canning recipes from the internet, old books, word-of-mouth, etc. Do not make up your own recipes.
- Follow the recipe and instructions exactly. Do not substitute or omit ingredients. This can change the acidity of the product.
- If the recipe says to pressure cook, do it! Pressure cooking and water bathing are NOT interchangeable methods. A pressure cooker is designed to bring low-acidic food up to higher temperatures.
- Process according to the appropriate time and pressure.