Fred
01-29-2005, 04:08 PM
I was always intimidated by the prospect of making a sourdough starter that could be used to make sourdough bread until I actually made one. The starter or "sponge" as it's called in the baking business is nothing more than a culture of yeast and bacteria in loose dough or batter.
Don't get fooled into thinking you can make a sourdough sponge with baker's yeast. You'll get a sponge after several hours of fermentation but it won't be the right kind. Sourdough is made from natural yeast and a bacterium that feeds on that yeast called Lactobacillus San Francisco. So where do you get natural yeast and this Lactobacillus? Well, it isn't hard. Here we go.
Get a glass bowl. Natural yeast don't really care for stainless steel or copper bowls so get a glass one or a ceramic one. Take about 1/2 lb of rye flour, put it in the bowl and add warm water to it until it forms a loose dough or firm batter. Cover it with plastic film and put it somewhere out of the way.
The next day, you should see bubbles forming on the top of the starter. This is a good sign. It shows you that the natural yeasts in the flour have begun to ferment some of the natural sugars in the flour. That's right, you had the yeast all along. It was right there in the flour. As the fermentation continues the yeast begin to die. The bacterium that feeds on these dead yeast is that Lactobacillus we were talking about earlier. There is some controversy about where these bacteria come from. Let's just say that if you make the starter, they will come.
On about the third day, the sponge will begin to cave in. It is time to feed it. Just add about a 1/4 cup of bread flour. You won't need any more rye. It has done its job. From now on use bread flour in your starter. Add water again to get it back to its original consistency. After about 5 days the starter is probably ready to use. It should have a somewhat alcoholic smell (caused by alcohol of course) and it should smell something like you expect sourdough bread to taste.
From now on, just replace the starter you take to make bread with more flour and water each time to replace what you took. After a few weeks the culture will become quite stable and predictable. My own culture is about a year old and behaves just like it did when it was a month old. That's all there is to soudough starter.
Some people keep their sponges in the refrigerator. I don't bother. I just keep it in the basement covered with film.
How do we use it to make sourdough bread? Pretty simple. The starter replaces the baker's yeast you would normally use to leaven the bread. If I make up a pound and a half dough, I generally add about 1/4 cup of starter in place of the yeast. I also reduce the water by a couple of ounces to keep the hydration ratio about right. Then my dough has to ferment for about 18 hours so sourdough does take some planning. The natural yeasts are much slower acting than commercial baker's yeast. So be patient. After fermentation, the dough will smell like sourdough. Just deflate it, make it up, proof it (for a couple of hours) and bake up some delicious sourdough bread.
Be sure your sponge gets a feeding at least once every other week. If you don't use any of it for a couple of weeks, just throw a little out, add some flour and water and cover it back up. That's a pretty brief description of sourdough breadmaking but it's enough to get you started. Enjoy.
Don't get fooled into thinking you can make a sourdough sponge with baker's yeast. You'll get a sponge after several hours of fermentation but it won't be the right kind. Sourdough is made from natural yeast and a bacterium that feeds on that yeast called Lactobacillus San Francisco. So where do you get natural yeast and this Lactobacillus? Well, it isn't hard. Here we go.
Get a glass bowl. Natural yeast don't really care for stainless steel or copper bowls so get a glass one or a ceramic one. Take about 1/2 lb of rye flour, put it in the bowl and add warm water to it until it forms a loose dough or firm batter. Cover it with plastic film and put it somewhere out of the way.
The next day, you should see bubbles forming on the top of the starter. This is a good sign. It shows you that the natural yeasts in the flour have begun to ferment some of the natural sugars in the flour. That's right, you had the yeast all along. It was right there in the flour. As the fermentation continues the yeast begin to die. The bacterium that feeds on these dead yeast is that Lactobacillus we were talking about earlier. There is some controversy about where these bacteria come from. Let's just say that if you make the starter, they will come.
On about the third day, the sponge will begin to cave in. It is time to feed it. Just add about a 1/4 cup of bread flour. You won't need any more rye. It has done its job. From now on use bread flour in your starter. Add water again to get it back to its original consistency. After about 5 days the starter is probably ready to use. It should have a somewhat alcoholic smell (caused by alcohol of course) and it should smell something like you expect sourdough bread to taste.
From now on, just replace the starter you take to make bread with more flour and water each time to replace what you took. After a few weeks the culture will become quite stable and predictable. My own culture is about a year old and behaves just like it did when it was a month old. That's all there is to soudough starter.
Some people keep their sponges in the refrigerator. I don't bother. I just keep it in the basement covered with film.
How do we use it to make sourdough bread? Pretty simple. The starter replaces the baker's yeast you would normally use to leaven the bread. If I make up a pound and a half dough, I generally add about 1/4 cup of starter in place of the yeast. I also reduce the water by a couple of ounces to keep the hydration ratio about right. Then my dough has to ferment for about 18 hours so sourdough does take some planning. The natural yeasts are much slower acting than commercial baker's yeast. So be patient. After fermentation, the dough will smell like sourdough. Just deflate it, make it up, proof it (for a couple of hours) and bake up some delicious sourdough bread.
Be sure your sponge gets a feeding at least once every other week. If you don't use any of it for a couple of weeks, just throw a little out, add some flour and water and cover it back up. That's a pretty brief description of sourdough breadmaking but it's enough to get you started. Enjoy.