I’ve sent these directions to PizzaMaking.com forum members who have requested free sourdough starter cultures from me.
These procedures have worked for me in the reactivation and maintenance of sourdough cultures from dried starters. Feel free to deviate from my suggestions based on your experience and inclination.
Reactivation of the dried starter is fairly straightforward. The starter is mixed with water and then refreshed periodically. I use spring water (to avoid the chlorine present in the municipal supply) and King Arthur bread flour or KA Sir Lancelot. (No need to use exactly the same flour as in your final dough)
Nothing other than flour and water should be added to your starter. NEVER add commercial yeast!
After the dried culture has been rehydrated and fed for several days, it may then be refrigerated. “Withdrawals” are made from this mother culture to build an overnight poolish to incorporate in your pizza dough.
Once established, a starter culture is fairly stable, but efforts should be taken to minimize the possibility of contamination. Make sure everything is very clean: your hands, containers, spoons, thermometer, work surface, etc. Try to minimize the amount of time the culture is exposed to the open air. Be careful not to cross-contaminate different cultures by using the same (unwashed) equipment in different cultures
Although a “mother” culture being held under refrigeration doesn’t need regular feedings like one held at room temperature, it should be refreshed and transferred to a clean container periodically. I do so about once a month.
If you are maintaining multiple cultures, it’s a good idea to label both the lid and the container w/ the type of culture and the date of last refreshment. (If only the lids are marked, it’s easy to put them back on the wrong container.)
Begin by pouring 4 oz. of spring water into a plastic container (Tupperware or Rubbermaid Servin’ Saver food storage containers w/ plastic snap- lids work well).
Microwave container and water for about 15 seconds on high (ovens vary) until water temperature has reached 95 degrees F. Use a (clean) thermometer to check this temperature. If it is too hot, allow temp to drop to 95 degree range before adding dried starter.
Add ½ packet starter to water (keep half as back-up) and stir/ chop-up dried starter with (clean) spoon. Mix for several minutes…the starter need not be totally dissolved.
Add 5 tablespoons bread flour and mix thoroughly.
Cover container with lid. Leave container at room temperature.
Swirl container a few times during the next 24 hrs.
Starter may show a few bubbles after 24 hours but may take as long as 36 hours before activity is noticeable.
Upon initial reactivation of the starter, I’d recommend regularly feeding the starter twice a day for at least three days in order to “stabilize” the culture prior to refrigerating or
using in pizza dough making.
After this initial three-day stabilization period the culture may be refrigerated, and a small portion withdrawn to inoculate a 50/50 spring water/flour mix for a shorter period (12 hrs.) prior to incorporation in dough.
If the starter is always doubled, you’d go through increasingly larger quantities of flour and need ever larger containers. Instead, simply dump-out half of the starter you have ,then rebuild the original quantity with new flour and spring water. For instance: If you had a pint of starter that needed refreshing, pour out half the pint of starter and add 7/8 cup of flour (4 oz. ) and ½ cup of water (4 oz.). to equal one pint (16. oz.) of newly refreshed starter.
I wish success and pleasure in your pizza making!