Captive Care of the Sourdough Starter, Making Bread the Ancient Way
Sourdough starter, how the ancients leavened their bread
I have considered writing a hub about sourdough starter as a recipe, however I have decided against it. Making and maintaining a sourdough starter has more in common with caring for an exotic pet than with cooking. The basic principle of using a sourdough starter to bake bread is very simple, rather than using cultured bakers yeast to leaven bread, you leave a mixture of flour and water to ferment, and rely on the bacteria and yeast, that are already present in the flour to multiply, until their numbers are high enough so the carbon dioxide produced through their respiration becomes trapped in the dough leavening the bread.
Because a by product of the respiration of the Lactobacillus bacteria in the sour dough is lactic acid, the bread has a delicious sour taste. The dough is also generally denser and more substantial that made with commercial yeast.
The sourdough starter was the first form of leavening available to bakers. It is thought that it dates back to Ancient Egypt, around 1500 BC. Personally I find it very satisfying to go back to basic techniques when cooking, to produce food from the fundamental ingredients and rely as little as possible on prettily packaged supermarket produce (within reason obviously, packaged microwave food definitely has its uses). Once bread started being mass produced, faster and easier methods were adapted, although I think a lot of taste was lost in the process.
Sourdough, bacteria and yeast
A sourdough culture basically consists of bacteria and yeasts that are naturally found in flour, propagated. Given a thin dough and some time at a warm temperature, these organisms will multiply and cause the starter to ferment. The main bacterium appears to be Lactobacillus sanfranciscenisis, so named because it was first identified in sourdough cultures in San Francisco, a city famed for its breads. The yeasts develop in symbiosis with the bacteria, although there is usually less of them, about 10% of the culture are yeasts, Candida mileri or Sachharomyces exiguous.
Making the sourdough starter, slow fermentation
A starter can be made by creating a thin mixture of flour and water. It is better to use whole grain unbleached flower since it is richer in micro-organisms. Although opinions vary, I think it might be safer to use dechlorinated water, either filtered or bottled. Some people swear that tap water is fine, while others worry that the chlorine in the water will kill the all important Bacillus. Some recipes call for the addition of unwashed grapes, while the starter for traditional Greek starter calls for using water in which basil leaves had been steeped. However I have found that I can make a good starter without any additions.
The mixture is kept in a warm place, and fed daily with more flour and water. During this process it becomes necessary to throw away about half of the mixture daily, unless you want to end up with a bathtub of the stuff. As time goes on the starter will start becoming fizzy and will develop a, not unpleasant, sour smell, as the flour ferments. This is the only potentially tricky part of the process, there are reports of the culture going bad, as the wrong types of bugs develop, although I’ve never had this problem.
Some people prefer to get their starter from commercial sources. Bakeries will often give you or sell you a bit of their own starter. You only need a small amount to start with, you can easily increase the volume by adding some more food (flour and water) for the sourdough bugs and yeasts to ferment. Properly cared for a culture can last indefinitely. I made the one I am using now about three years ago, but some bakeries have cultures that are decades long.