The “Mother”, or generative source of vinegar, is a cloudy, gummy substance composed of cellulose and bacteria. Louis Pasteur first showed it was Acetobacter aceti that was the particualr bacterium responsible for the conversion of ethanol into acetic acid. Though ubiquitious in the wild, Acetobacter aceti tend to frequent what scientists call “alcohilic ecological niches”. No, these are not dive bars in college towns. They are natural areas of moisture around flowers, fruits, honey, or wherever sugar fermentation naturally occurs.
If you wish to start a healthy Mother, you must either find and remove a bit from the bottom of a bottle of good vinegar, or go buy yourself a healthy starter-dose of Mycoderma Aceti from a local brewers outlet or wine merchant. The clear fluid comes in a small phial and can be added to any large open-mouthed crock along with a bottle or two of wine (preferably made from organically-sourced fruit), and set in a warm, well-ventilated spot in your kitchen or pantry.
Now, roughly once a week or so for the next few months, add a glass of wine to the crock. Obviously, this will force you to buy and drink a slightly excessive amount of wine on a regular basis, but every art, even the art of fermentation, demands a measure of sacrifice.
After just a few weeks your Mother will appear as a hazy grayish veil that drapes herself protectively over the surface of the wine in the crock. To keep your Mother healthy you must give her plenty of breathing room. This means leaving sufficient empty space in the crock, and loosely tying a piece of linen or cheesecloth over the mouth of the container. This will provide her with the oxygen she needs and also prevent the unwanted intrusion of flying insects.
Just keep offering your Mother a glass of wine every week or so for the next few months until the crock is two-thirds full. Don’t go overboard. Adding too much wine at once will weaken her maternal instinct. Most importantly, never give your Mother sweet or fortified wines (port, sherry, etc.), as they will delay or even prevent fermenttion.
After a month or two your Mother will begin to thicken as she defends her brood of bacteria from the elements. Someone with way too much free time on their hands once calculated that a typical Mother actually thickens at a rate of roughly 1.25 inches per year.
As more of the wine is transformed into vinegar (you can use your finger to moniter the growing acidity level), you will notice your Mother begin to weaken and descend through the wine to the bottom of the crock. Eventually, she will hit “crock-bottom” so to speak. At this point she can either be moved to a new crock with some fresh wine to begin a new batch, or discarded altogether. After she is gone, The vinegar remaining in the crock now needs only to be strained through a folded piece of cheesecloth in order to remove any last bits of cellulose and transferred to smaller bottles for storage.