- Apr 19, 2009
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Because wiping the rim with your finger is not very sanitary. I know that it doesn't really touch your food, but by not warming up the lids, you are also not killing any of the germs on the middle of the lid. IMO, warming the lids up is a small/easy task that greatly increases the sanitaryness (not sure if that's a word)
Warming the lids does not kill any germs on the middle of them, nor does it kill any germs that would be between the seal and the rim of the jar. Pre-heating lids should never be done in boiling water, only simmering and simmering water is not hot enough to sanitize anything. That's the canner's job and the reason the jars, once assembled, are run through either a boiling water bath or a pressure chamber depending on the contents.
That said, you're right that it's not a good idea. Not because it won't work immediately or that it isn't sanitary, but because it doesn't offer the best seal longterm and stored jars can more easily lose their seal months down the road. If you've ever taken a jar from your pantry and discovered the lid was no longer attached, you know the disappointment of that wasted food -- and if you have kids you can imagine the danger in having that happen in your pantry. Kids are not always the most observant and could easily consume tainted food without noticing that the lid had lost its seal.