- It is difficult to prepare a sourdough starter from scratch. Microorganisms naturally present in the ingredients may not be the ideal ones for producing a good starter or some other necessary condition may not have been met. It takes experience with the art of sourdough to recognize a really good starter. Most bread cookbooks have sections on sourdough.
- Discard starters that smell bad, turn reddish or orange in color or grow mold. Good starters are bubbly and have a sour smell; the Amish Friendship Bread starter should smell sweet and tangy.
- Neither pasteurized nor raw milk are good choices for preparing a starter from scratch. Pasteurized milk probably will not produce enough lactic acid to form a good starter, because pasteurization kills the lactobacillus organisms in the raw milk that would initiate fermentation. Eventually you just get a foul-smelling spoiled mixture. People are able to keep already-started starters going with additions of pasteurized milk because the organisms are already there from the original starter culture, which may have been started from raw milk, a possible source of pathogenic bacteria.
- Starters originally started with raw milk may be a source of pathogenic bacteria, such as E. coli O157:H7. Never taste a raw starter. Baking to doneness will destroy harmful bacteria that might be present.
- Cultured buttermilk, water or yogurt with active bacterial cultures are good choices for preparing a starter. For starters that call for water, flour and sugar -- and perhaps yeast -- the use of whole wheat or rye flour may give a better inoculum of lactic acid-forming bacteria than white, all-purpose flour.
- Follow the usual recommendations for personal and kitchen cleanliness while preparing starters.
- You can refrigerate or freeze starters, and Cornell recommends storing starters in the refrigerator after the fermentation has progressed satisfactorily -- follow the recipes for this. Refrigeration does slow it down, but you can get it going again by warming them to room temperature a few hours before use in baking.