1/2 cup whole wheat or rye flour (or other whole grain)
1/2 cup slightly warm water (filtered or de-chlorinated)
In a quart-sized wide mouth jar, mix together the flour and water. Cover the jar with a loose lid or a piece of muslin cloth secured with a rubber band. Let it sit for 24 hours at room temperature (about 60-70 degrees).
After 24 hours, remove about 1 tbsp of starter. Compost the rest of the starter. (We know, it seems so wasteful, but you’re coaxing the population of wild yeast and bacteria into balance, so you have to get rid of the ones that have died valiantly for your cause!) Add 1/2 cup water to the reserved starter. Stir to combine, then add 1/2 cup flour and stir well. Cover and let it sit for another 24 hours at room temperature.
Then simply repeat, repeat, repeat : every day, reserve 1 tbsp of starter (compost the rest) and mix in equal parts whole wheat flour and water.
After about two weeks, you should have a healthy sourdough starter. A healthy starter will LOOK plump and bubbly, SMELL pleasantly sour and yeasty, and TASTE pleasantly sour and doughy.
As your starter matures, (over weeks, months and years) it will develop more nuanced flavor and overall heartiness.
Follow our Sourdough Feeding Guide to sustain your starter long term.
Recipe adapted from Josey Baker Bread.