Usually, when a jar has a label that can be removed, we soak it off so that the only label on the jar is the one where we write what food is in it now and the numbers for purchasing. That looks better and is less confusing. I just demonstrated another reason:
If a jar’s original label had metallic printing on it, and you put it in the microwave, it will give off sparks and an unpleasant smoke smell. Why would you microwave a jar? Well, if that jar is full of honey that has crystallized, a few seconds in the microwave will soften it so that you can pour it out.
But if that jar has a metallic label that you did not remove but only covered with the co-op label, this is what happens in only six seconds in the microwave:
Yikes! There was no damage to the honey, my microwave, or myself–but I wonder if whatever chemicals in the labels turned so black have created something that’s not safe to handle. I decided to use a new jar of honey in the zucchini bread (I’m revising my recipe–stay tuned!) and figure out what’s best to do about this jar tomorrow.