The reponses included to freeze it, to make confit or to preserved it in salted water or oil.
I've tried every methods, but confit that's on my list for next time I have garlic, and I've been consuming fermented garlic.
I'm very proud of that first attempt at salt fermentation (^_^)
More recently I've decided to taste my garlicky oil and I've open one of the jars. The bubbling oil was so active it splash a bit around. So I close it wondering what I have done wrong : 3 months ago, I've peel the skin that was on the older garlic heads, cut any bad looking part, place the garlic with some fresh thyme, fill the jar with olive oil and store it lip tight on a dark shelf.
So first : Thank you for all the idea. It was fun, tasty and avoid plenty of waste.
Second : Do you know what is wrong with the garlic preserved in oil ? Is it simply carbonic gaz from the fermentation that build up ? Should I have blanch my garlic or dried my thyme before hand ?
My parents grow garlic for their own use, and they literally just store it in a basket. No conservation needed. Fine for a year! But this is in Norway, dry and cool (but not cold - they store it in the kitchen), not sure if that matters.