Sourdough Starter Guide
Create and maintain a living starter for naturally leavened bread
Sourdough Starter Encyclopedia
Living culture for naturally leavened bread - wild yeast magic
Starter Development Timeline
Sensory
Minimal activity, smells like wet flour
Activity
Microbes from flour and environment start multiplying slowly
Sensory
Small bubbles, slight rise, fruity or yeasty smell
Activity
Lactobacillus bacteria produce lactic acid, wild yeast populations grow
Sensory
Very active then quieter, may smell sour or acidic
Activity
Initial bacteria dominate, then stable sourdough microbes take over
Sensory
Pleasant sour smell, doubles in 4-8 hours after feeding
Activity
Stable community of lactic acid bacteria and wild yeast established
The Science of Sourdough
Sourdough starters contain wild Saccharomyces yeast (not commercial baker's yeast) and lactic acid bacteria (LAB). The yeast produces CO2 for rise and ethanol. LAB produces lactic and acetic acids for sour flavor. This symbiotic relationship creates bread with complex flavor and natural preservation.
Flour isn't sterile - it contains dormant wild yeasts and bacteria from the grain and milling environment. Whole grain flours have more microbes because the bran and germ harbor diverse populations. When you add water, you activate these dormant microbes.
After feeding, yeast and bacteria consume sugars and produce gases. The starter rises as CO2 becomes trapped in gluten structure. Eventually, food runs out, acid builds up, and the starter collapses. This predictable cycle indicates a healthy starter.
Hydration percentage (water to flour ratio) affects microbial balance. Wetter starters (100%+ hydration) favor lactic acid bacteria, creating milder sour flavor. Stiffer starters (50-80% hydration) favor acetic acid production, creating sharper tang.