Sourdough Started

Sourdough is a tricky beast. You need to sneak up on it sideways, taking care but with a dash of reckless abandon. Most breads are made with some variant of baker's yeast, but not soursough. With the latter, you throw a few simple ingredients together in a bowl and leave them open to the world, hoping, no praying, that Saccharomyces exiguus yeast will alight and take hold before anything else more vile can take roost.

In the past, a sourdough starter was the only reliable way to make bread for some people. My sister used to lead tours of the Chilkoot Trail in Alaska, and tells stories of how gold prospectors would carry a dried chunk of sourdough with them, feeding it with fresh water and flour a few days before they wanted to make bread. (More often than not, they didn't have the money for flour for bread. It's the thought that counts, right?) Today, sourdough is still popular, especially in the San Francisco area, a region famous for the distinctive taste of its sourdough.

To make a starter, start with a very clean bowl. We're trying to get avoid bad bacteria, so let's not give them any head start. Mix equal parts water and flour. Two cups of each is a nice amount. Add salt, maybe a 1/2 teaspoon. Cover the bowl loosely with a clean towel and put it aside. Stir once or twice a day to aerate and mix. Within 2-3 days, you will hopefully have a bubbling brew of sourdough starter.

What has happened is that the sourdough yeast, often present on flour grains or in the air, has alit on the flour mixture. The yeast forms a symbiotic relationship with lactobacillus bacteria (also floating around) and begun to feed on the starches in one big eating frenzy. The bubbling is millions upon millions of tiny carbon dioxide burps from satiated yeasts.

Why don't stinky, vile bacteria and yeasts take hold instead? Sometimes they do. My first attempt at a starter several weeks ago went skunky and smelled foul beyond belief. In general though, chemistry is working in your favor. Most wild bacteria in the air feed best on sugars and don't do as well with the starches in a starter. As soon as the good bacteria begin to take hold, they produce lactic and acetic acids as byproducts, making the starter an even less hospitable environ for other bacteria. This lactic acid, the same as can be found in yogurt and buttermilk, is also what gives sourdough it's mild, sour bite. The process also produces small amounts of watery ethanol on the surface of the starter. Gold miners used to drink this foul smelling hooch, but you should stir it back into the starter. Trust me on this one.

One important note: sourdough starters, like small children, need occasional feedings. Once the bubbling has started and you have a nice sour smell wafting up, take a cup of starter out every day and replace it with an equal amount of flour/water mix. If you're not going to use the starter in the near future, put it in the fridge and feed it every week or two instead.

Any questions? In coming posts, I'll cover sourdough recipes as I try them.