Homemade Vinegar1 part Bragg Apple Cider Vinegar (with the mother)
3 parts alcohol (red wine, white wine, champagne, beer, cider, whatever)
Mix the ingredients together and store in an open container. Cover the top of the container with cheesecloth or a coffee filter - make sure your cover allows air to reach the vinegar, since air is actually the key ingredient here. Put your container in a cupboard or garage or basement or something - somewhere dark with a steady temperature. Allow the vinegar to sit for 4-6 weeks. Taste it along the way, when it tastes like vinegar, put a lid on it and it is ready for use. Save the last bit, plus all of the mother, to be your starter for the next batch.
The core of homemade vinegar comes from the vinegar mother, which you can get in stores by buying Bragg Apple Cider Vinegar (on the label it says "with the mother"). Think of vinegar mother in the same sense as bread starter or something, it's the core, the starting point of the vinegar. It is a weird gunky film that is composed of cellulose and acetic acid bacteria (Brock compares it to a jellyfish, I think that is pretty appropriate). The vinegar creation process is the act of the mother interacting with the air and converting alcohol to acetic acid. What is really interesting about that process is that few things actually consume alcohol, and acetic acid bacteria is one of them. The mother is really gross looking, in fact, at first I thought something was wrong with my vinegar, and my wife and I were both super grossed out by it. It develops as a skin on top of the alcohol where it interacts with air. Every week I would check on my vinegar and smell it, and swirl the jar to get the mother to mix into the vinegar. I don't know if that is good or bad, but I assume that if we want air to be in contact with the vinegar and we want the mother to be the interacting agent with the air, then swirling existing gunk into the vinegar and allowing more gunk to form on the top is probably a good thing. I could be totally wrong though.
I guess the first disclaimer here is that I have not actually used the vinegar in a recipe yet, but I tasted it on its own and it was quite good. Just look at that red wine vinegar in the photo, it looks like balsamic or something. It's so thick - and it has all of the characteristics of wine. It has the initial tartness that you expect from vinegar, but storebought red wine vinegar is just that one note (and is also translucent, but wine is not translucent.. Hmmm.. makes you wonder). This vinegar is rich, it has body, it still tastes wine-y at the end. Brock tells a story of inheriting his grandmother's 40 year old vinegar starter and keeping it going. I can only hope that this experiment kicks off the beginning of a long-lasting vinegar tradition for my yet-to-exist kids and grand kids.