250gramsbread flour (9 ounces or approximately 2 cups)
250mllukewarm water (10 tablespoons or 9 fluid ounces)
Ingredients for Feeding Starter:
100gramsbread flour (3 ½ ounces or approximately ¾ cup + 1 tablespoon) approximately ¾ cup +1 tablespoon bread four
100mllukewarm water (7 tablespoons or 3 ½ fluid ounces)
Instructions
Slice grapes in half and combine with flour and water. Tip into an airtight container and let sit at room temperature for three days. I've used a large mason jar or a covered mixing bowl. The mixtures will bubble and grow quite a bit so use a large enough container.
After three days, remove the grapes and discard half of the mixture. “Feed” the remaining starter (100 grams starter) with 100 grams flour and 100 grams water. Stir until thoroughly combined. Leave in the same airtight container for another 24 hours.
After this, the starter should be ready to use. The starter should be bubbly and about the consistency of pancake batter. If your mixture is not bubbly, that means the bacteria is not active, feed it again and let sit in container for a couple of days.
If you’re planning on making sourdough bread regularly (like, once a week), then you should discard half of the starter and refeed the mixture every couple days. The mixture is best left at room temperature (except on very hot days--then place in fridge).
If you are making bread less than once a week, you can store the starter in the fridge. Refeed it weekly if storing in the fridge. To use from the fridge, pull the starter out and let come to room temperature. Refeed and use once starter shows signs of activity.
Remember to discard and refeed the starter after you make bread every time.
Notes
You can feed your starter more or less, you just need to be consistent with the ratio. For feeding by weight do a ratio of 1 part starter, to 1 part flour, to 1 part water.For volume, do a ratio of 1 part starter, to 2 parts flour, to 1 part water.Once stable, you can feed your starter 1x a day or if refrigerating it, feed it 1-2x a week.