I followed the sourdough starter recipe out of Sunset's Bread book. Mixed warm milk and plain yogurt and let it sit a day or so, then mixed flour with it and let it sit for 4 days (the book says 2-5 days, until it's bubbly). Today is the 4th day and I opened it to find mold. Am I doing this wrong? Aren't you supposed to leave it in a warm place until it bubbles, THEN you refrigerate it??

-- gita (gita@directcon.net), January 31, 2002

Answers

I have never tried to go from yogurt to sourdough starter, so I did a little search and found: I have my students gram stain a small bit of the yogurt to see that there are actually living bacteria in it. The bacteria we see are Gram positive (purple) and are cocci (round) in chains (Streptococcus lactis) and bacilli (rods) in chains or singles (Lactobacillus sp.) These are bacteria that use lactose (milk sugar) for their energy source. The acids they produce as end products of their metabolism (waste)curdle the milk protein and also give the sour taste to the yogurt.

You need yeast, not bacteria for sourdough starter. Given the result above, it is no suprise that you had all kinds of things growing in your container.

Perhaps your recipe meant that adding yogurt to sourdough bread mix would enhance the sour flavor.

-- BC (desertdweller44@yahoo.com), January 31, 2002.

Using the yogurt, your sour dough is not developing sour yeast (which it is suppose to do)..it is just going bad and producing bateria mold (the bad kind of bateria). The same type of bateria that makes milk go sour then change from sour milk to rotten milk.

Switch to a basic sour dough starter from some of the other posts. Once it "sours" and foams and separates into liquid from solids, if you don't use it every day or two, then you should refrigerate it and feed it with equal parts of water and flour every month. Be sure you stir it real well before using and before adding the feeder. Be sure also to stir real well after feeding it.

If you can't find the sour dough starter recipes, email me I will be glad to give you a couple that I have had excellent results with.

-- Karen (mountains_mama@hotmail.com), January 31, 2002.