Sunday, 20 September 2009

On Sourdough Starters

by Kate
Living The Frugal Life

I got interested in bread baking as part of a frugality kick about two and half years ago. It wasn't really that much of a departure for me, as I trained professionally as a chef and am pretty comfortable knocking around a home kitchen. But I never expected to get to the point where all the bread we eat is made at home, by me.

I save a considerable amount of money by making our bread. Buying our flour in 50-pound bags helps even more, and I've stockpiled enough bread in our chest freezer to get us through summers without the need to bake and heat our house up when it's already hot outside. On the other hand, baking in winter helps us use less heating oil in our furnace. But when it comes to the yeast in the bread we eat, there's only a very minimal savings to be had in using a sourdough starter instead.

Sourdough bread has its virtues, taste not least among them. It's also widely held that bread made from sourdough remains fresh longer than bread made with purchased yeast. But undeniably, sourdough has its drawbacks as well. It is far more temperamental than any manufactured form of yeast. It needs tending to, and is not always ready the moment when baking is most necessary or desired. It requires more planning, and perhaps most crucially, more judgment from the baker, which of course must rest on the baker's experience and skill. So if you are new to the art and science of baking, you might want to spend a year or two working with the far more predictable active dry or instant yeasts. But despite these drawbacks, sourdough breads persist because they are delicious and because they use yeasts that are always freely available.

From what I've read, a well established sourdough starter always contains and is dominated by the local micro-organisms of the area in which it's found. The three major micro-organisms are yeast, lactobacillus and acetobacillus. We breathe all three of these in with each breath we take, as they thoroughly permeate our environments. Fortunately, they are all harmless to humans. In bread doughs the bacteria compete with the fungus (yeast) for the same nutrients. While yeast produces bubbles of carbon dioxide that cause the dough to rise, the bacteria are busy breaking down parts of the starchy flour and creating flavorful byproducts in the process. (This is why good bread tastes considerably better than raw flour.) In doughs made with commercial yeast, especially doughs made with added sweeteners, yeast gets a serious leg up on the lactobacillus and acetobacillus, outcompeting them and smothering any effect they would have on the dough. Such breads are either lacking in flavor, or they have flavoring ingredients - natural or otherwise - added in to make them tasty. But in doughs made with only very small quantities of commercial yeast (which therefore require very long rise times), the acetobacillus and lactobacillus naturally present in the flour and air have a chance to contribute to the flavor of the bread. Sourdough starter already has populations of all these micro-organisms in a more or less friendly balance. That's what gives the bread its distinctive flavor.

Different regions have different wild populations of acetobacillus, lactobacillus, and yeast. Think of the cities of the world which are famed for their bread. Those cities are blessed with some of the very best populations of these micro-organisms as far as bread baking goes. Even if you were to smuggle a sourdough starter back from one of these illustrious bread cities, after a few weeks the flora and fauna local to your area would take up residence in your starter and outmuscle the imports. (Unless of course you bake bread in a surgically sterile cleanroom.) So given a little time, sourdough is always a local product.

If you want to work with a sourdough starter, you can start one from scratch. Or you can acquire a portion of someone else's starter. I have even used the cheater method of saving a bit of store-bought raw pizza dough to begin a starter. You could also send a self addressed stamped envelope to Carl's Friends for a little bit of dried sourdough starter.

If you want to follow the from scratch method, I recommend beginning in either spring or fall, when room temperature is roughly 65-70 F/18-21 C. You can find a detailed walkthrough for beginning a sourdough starter here, using a few different variations. One method I have found to work well is to begin with whole rye flour, which naturally contains more yeast than wheat flour. Of course, these yeasts come from wherever the rye was grown, but the local yeast will take over soon enough. Whole rye starters are rather smelly and don't rise much at all in the first few days, so don't be alarmed if you observe these traits when working with whole rye flour. If you have chlorinated water, be sure to allow it to sit out overnight before mixing it into the starter. You will need to repeat this off-gassing for chlorinated water at each stage of the starter process, so it may be worth your while to seek out some well water or spring water for this project.

There's an entire world of breads, pancakes and crepes out there that you can explore once you have a sourdough starter ready to go. Have fun with it!