Hi! My mother had an abundance of grapes growing in her garden, and I figured I would experiment and try to make a starter with them. I mixed 2 cups of the grapes with 2 cups bread flour and 2 cups water. Within the hour there was some bubble activity, which continued into the evening. However, when I checked this morning the dough was covered with about 1/4 inch of liquid and no bubbles at all. Thoughts? This is my first time trying this, so I don't know if the liquid is mold scum or what. Thanks in advance.
Most likely water. I've done this with wild blackberries years ago and it does work, but, initially you'll have an abundance of yeast and little labs (which give the sour in sourdough). To get the proper balance between the 2 will take a little time - about like creating a starter from scratch. Keep in mind that a cup of water is equal to about 2 cups of flour (why I say it's probably water floating on top). As long as you've started the process, keep it going, but reduce the water so you have more of a paste like consistency. Then go with 1 part starter to 3 parts flour and a little water to get that pastey consistency daily till it gets sour. Probably a week or 2. To keep from getting a massive amount of starter, start very small. Enjoy!
I made a grape starter in the mid-90s but approached it differently as I wanted the yeast from the grape skins to be vigorous before adding flour, which contains its own yeasts.
I crushed the grapes, added some spring water, and sugar to a sanitized container and left it to ferment. When the young wine was bubbling away I strained the must and only then added flour. I then cut it each day with spring water and flour until I had a starter. The acidity of the wine seemed to help keep the gassy beasties at bay.
I tried the same thing again recently with wild plums and the result was a starter that produced very fruity bread (probably via malic acid). You can read my experience here:
http://www.thefreshloaf.com/node/61024/starter-young-wine
Thank you both phaz and BobbyFourFingers! I appreciate your thoughts and will continue to nurture this little beastie.
Happy fermenting :)