My husband is canning medium hot peppers in a vinegar, water, sugar ,salt, and alum

Solution . He adds dill , when he added the garlic cloves they turned BLUE within 30min.


WHAT is going on here and are they safe to eat ?

According to my canning cookbook, nothing is wrong if garlic turns blue. This is the explanation of why that happens:

The discoloration is due to pigments that form between sulfur compounds in garlic and amino acids. When the garlic tissue is disrupted, as happens in processing, an enzyme is liberated and reacts with it to form thiosulfinates compounds that then react with the natural amino acids in the garlic to form blue pigments. The age of garlic determines how much isoalliin there is in the first place, and the nature of the processing determines how much enzyme is liberated.

Just enjoy the fruits of your labor !