Sourdough Bread

Secrets of real sourdough bread

Sourdough bread is made by the fermentation of dough using naturally occurring lactobacilli and yeast. Sourdough bread has a mildly sour tastenot present in most breads made with baker’s yeast, and better inherent keeping qualities than other breads due to the lactic acid produced by the lactobacilli.

The origins of bread-making are so ancient that everything said about them must be pure speculation. One of the oldest sourdough breads dates from 3700 BCE and was excavated in Switzerland, but the origin of sourdough fermentation likely relates to the origin of agriculture in the Fertile Crescent several thousand years earlier … Bread production relied on the use of sourdough as a leavening agent for most of human history; the use of baker’s yeast as a leavening agent dates back less than 150 years.”

Sourdough remained the usual form of leavening down into the European Middle Ages until being replaced by barm from the beer brewing process, and then later purpose-cultured yeast.

In the southern part of Europe, where panettone was originally made with sourdough, sourdough has become less common in recent times; it has been replaced by the faster-growing baker’s yeast, sometimes supplemented with longer fermentation rests to allow for some bacterial activity to build flavor.

The sourdough tradition was carried into Alaska and the western Canadian territories during the Klondike Gold Rush of 1898. Conventional leavenings such as yeast and baking soda were much less reliable in the conditions faced by the prospectors. Experienced miners and other settlers frequently carried a pouch of starter either around their neck or on a belt; these were fiercely guarded to keep from freezing. However, freezing does not kill a sourdough starter; excessive heat does. Old hands came to be called “sourdoughs”, a term that is still applied to any Alaskan or Klondike old-timer. The significance of the nickname’s association with Yukon culture was immortalized in the writings of Robert Service, particularly his collection of “Songs of a Sourdough”.

Sourdough bread has a relatively low glycemic index compared with other types of bread.