Step 1

Take 50 grams of ripe or over-ripe sourdough starter. Place it in a jar. Add 50 grams water and 50 grams flour. Mix together until combined. Scrape down the edges and mark with a rubber band or dry erase marker so you can judge how much the starter has risen. Cover the jar with a loose fitting lid or plastic wrap and set in a warm 78ºF place to rise.Note: This recipe shows an example of a 1:1:1 feeding ratio. I recommend a minimum of equal weights of starter, flour and water be fed at any feeding. You can adjust the actual amounts to work for you.

Step 2

Over the next few hours, the sourdough starter will go through a fermentation cycle where it will begin to rise. Once it has at least doubled in size and reaches a peak height, it will be very bubbly throughout and smell milky sweet. If your starter is being kept around 78ºF, it will be peaked and active in about 3-4 hours. At this point the starter is ripe, active and ready to be used in a sourdough recipe.

Step 3

If you do nothing to it, the starter will continue through the fermentation cycle and will fall back down. It will become runny and will need to be re-fed to be used as active starter again. Discard (throw away or store in the refrigerator to use in a discard recipe) 100 grams of the starter. Feed the remaining 50 grams of over-ripe starter with 50 grams of water and 50 grams of flour to begin the cycle again.

Step 4

Continue this cycle of feeding and then discarding the sourdough starter to keep your starter active and strong. You can re-feed the starter any time as it falls back down. At a minimum, once the starter has completed the fermentation cycle, it should be fed again. I find it helpful to change my feeding ratio, alter the temperature, and use my refrigerator to make a sourdough starter work for me (see recipe notes for more information).