Can I make real, sour, sourdough bread if I don’t live in San Francisco?
So asks reader Dean (and Liz, and Darren, and Susan). The answer is a definitive “maybe”. There’s no question that bakers in the Bay Area have the edge when it comes to creating very sour breads. However truly sour, naturally-leavened loaves are possible in other regions of the country (or world), provided you can manipulate your starter’s moisture level, temperature, and rising/proofing times in the right way.
Allow me to explain. All bread starters are tag teams of yeasts and bacteria, with yeasts being primarily responsible for the rise, and bacteria for the flavor. The lion’s share of that flavor comes from acid, which is produced by different types of bacteria in varying amounts. As you might expect, the starter bacteria the thrive in the Bay Area, L. sanfranciscensis and L. pontis, are world champs in realm of acid production. L. sanfranciscensis produces unusually high levels of lactic acid, while L. pontis makes mostly acetic acid, which is the stuff that gives vinegar its sharp flavor.
READ ON