This is question we get quite regularly. Both our Spicy Pickled Garlic and our Pickled Garlic with Dill can sometimes have garlic in it that takes on a blue-green colour.
Here's the skinny on why that happens. It's all due to chemistry folks. Garlic contains an odourless sulfur compound called alliin. It also contains an enzyme called alliinase. Both alliin and alliinase are released when garlic is crushed or chopped - and when those two are combined it produces a component called allicin, which gives garlic that familiar pungent smell or flavour. When garlic is combined with an acid, in this case such apple cider vinegar or white vinegar, the allicin reacts with amino acids (proteins) in the garlic to produce rings of carbon-nitrogen called pyrroles. Pyrroles linked together form polypyrroles (multiple pyrroles) , which give off those lovely colours that you see. Four pyrroles clustered together create green (this is why chlorophyll is green). Three pyrroles together creates the blue colour.
Here's the other great thing - it does not change the taste or flavour whatsoever. And above all, it's perfectly safe to eat.
Fun fact: in many cultures around the world, blue-green garlic is prized and is considered
very healthy to consume. In China, the making of Laba garlic is celebrated, especially during the Lunar Festival. Laba garlic, is a specially preserved garlic which is pickled in (you guessed it? Laba vinegar. And of course, it's blue-green!
In my Ukrainian culture and heritage, I grew up with garlic being the core of practically everything that was cooked. There is a saying in my culture, which I have never forgotten: "start cooking your garlic (and onion too) in the pan, and then plan your meal around it". I still do this to this day. In fact, Sudbury, Ontario - my hometown - was the home of the first ever Garlic Festival in all of Canada. Since then, the 'food of the Gods' has been celebrated all over the country, and continues to do so, no matter the colour!
So, our advice? Enjoy your garlic, no matter the colour - like we do. :-)
Oh, and if you are interested in buying our great garlic that we grow on the farm, here's the link to the store: https://www.angelstarfarm.ca/product-page/pickled-garlic-with-dill
/olena at asf