A 2 gallon safe plastic or glass container, about a 7 ½ liter capacity, well cleaned
A large rubber band
Plastic wrap
Ingredients
1medium potatounpeeled and cubed
3 ½cups28 fluid ounces water
Unbleached bread flour
1teaspoon6 grams granulated sugar
Instructions
Bring water and cubed potato to a boil in a saucepan for about 12-15 minutes, or until the potato chunks are fork-tender. Allow the mixture to cool to about 78 degrees Fahrenheit (about 25 degrees Celsius).
Measure out 2 cups (16 fluid ounces or 480 ml) of the potato water, saving the potato for another use. Discard the remaining water.
In the 2 gallon container, mix together the 2 cups of potato water, 1 ¾ cups (8 ¾ ounces or 250 grams) bread flour, and granulated sugar. Use a wooden spoon and blend well.
Cover the container with plastic wrap and secure with a large rubber band. Let it sit out at cool room temperature, about 70-75 degrees Fahrenheit (21-24 degrees Celsius) for 24 hours.
Stir the starter once every day, and allow it to sit for 3 more days.
On day 4, the starter may begin to separate. Feed the starter by stirring in 1 ¼ cups (9 ounces or 255 grams) bread flour and 2 cups (16 fluid ounces or 480 ml) of 78 degrees Fahrenheit (25 degrees Celsius) water.
Cover the starter with the plastic wrap and rubber band, and allow it to sit for 4 more days (to day 8) at cool room temperature. Do not stir.
On day 9, begin a regular feeding schedule of 3 feedings per day approximately every 4-6 hours. The feedings should consist of 1 cup (8 fluid ounces, 240 ml) cool 78 degrees Fahrenheit (25 degrees Celsius) water and 1 ¼ cup (6 ounces or 185 grams) bread flour. Feed the starter first thing in the morning, the second feed at about mid-day, and the third before you go to bed.
Feed the starter for 3 more days, through day 11.
On day 12, you can begin baking with your starter.
Notes
NOTE – if you want to limit the amount of starter you are producing, before the first feed of the day, discard all but 2 cups of the starter, wash out your container, begin the day’s feedings with the remaining 2 cups.NOTE – after you have used a portion of your starter in a recipe, remember to save 2 cups of the starter and place it in a smaller, air-tight container, dated and labeled, and placed in the refrigerator for 2-4 months.