In the last Release the Yeast we talked about how yeast does the work that eventually gives us alcohol; this time we’re turning our eyes to the other staff of life – bread, more specifically sourdough bread. Funny thing is, sourdough cultures aren’t just exclusively used for breads and bread products like pancakes and biscuits; you can conceivably make beer with them too.
So what is it?
Sourdoughs are symbiotic relationships between wild yeasts and a lactobacillus bacteria; one such is named Lactobacillus Sanfranciscensis, for its discovery in San Francisco — the spiritual home of modern sourdough. The yeasts provide the leavening action — or puff — to the dough. The sour flavor is the result of the growth of the bacteria, and its acid production. Different lactobacillus strains produce different levels of sourness, some like San Francisco’s are very aggressive, others — like the Parisian strains — are much more mild in character.
In antiquity, all breads were sourdough breads. Most anthropologists believe that the first leavened breads were baked in Egypt. You can imagine how this was discovered, unused flatbread dough suddenly rising with the breath of the gods out of nowhere, that was then baked and deemed divine in flavor and texture. Not until yeasts were actually isolated and then made widely available did humanity know how to make a bread that wasn’t the result of a yeast organism captured in the wild and then cultivated as sourdough. (more…)