How to Make Sourdough
Sourdough starter is a fermented mixture of flour and water that captures wild yeast and lactic acid bacteria from the environment. This living culture is used to leaven bread, creating complex flavors and improved digestibility compared to commercial yeast.
Category: Grains & Tubers · Method: Alcoholic/Yeast · Time: 5-7d · Difficulty: 2/5 · Yield: ~500g · Temp: 21-24°C
History
Sourdough is the oldest form of leavened bread, dating back to ancient Egypt around 1500 BCE. Before commercial yeast was developed in the 1800s, all leavened bread was sourdough. San Francisco became famous for its sourdough during the Gold Rush.
Ingredients
- 500g total over 5-7 days All-purpose or bread flour — Unbleached preferred
- 100g for initial days Whole wheat or rye flour — Contains more wild yeast and nutrients
- 500ml total Water — Filtered or dechlorinated
Equipment
- Glass or plastic jar (1 quart)
- Kitchen scale
- Wooden or plastic spoon
- Rubber band to mark rise
- Loose lid or cloth cover
- Thermometer (optional)
Instructions
Float test
When starter is bubbly and doubles reliably, test by dropping a spoonful in water. If it floats, your starter is ready to bake with. Note: This test is most reliable for white flour starters; high-percentage rye or whole wheat starters may fail to float due to bran particles breaking surface tension, even when fully active.
Time: 5 min
Tip: A mature starter smells pleasantly sour and yeasty, not like nail polish remover.
Fermentation Timeline
- Day 1-2: Colonization — Bacteria and yeast from flour and environment begin to grow. May smell unpleasant.
- Day 3-4: Competition — Different microbes compete. Starter may rise then fall flat. This is normal.
- Day 5-6: Stabilization — Beneficial lactobacilli and wild yeast dominate. Pleasant sour smell develops.
- Day 7+: Maturity — Reliable rise and fall cycle. Ready to bake with and maintain.
Signs of Success & Spoilage
Good signs
- Doubles in size within 4-6 hours of feeding
- Passes float test (primarily for wheat-based starters)
- Pleasant tangy, yeasty aroma
- Bubbly throughout, not just on top
- Consistent behavior day to day
Warning signs
- Pink or orange streaks/film: This indicates harmful bacteria (like Serratia marcescens). Discard the entire starter and sanitize the jar.
- Fuzzy mold (white, green, or black): Discard immediately.
- Smells like acetone or vomit (feed more often)
- No activity after 7+ days
- Black liquid (hooch - needs feeding but not dangerous)
Troubleshooting
- Starter not rising
- Cause: Too cold, chlorinated water, or not enough time Solution: Move to warmer spot. Use filtered water. Be patient - some starters take 2 weeks.
- Smells like alcohol
- Cause: Hungry starter - yeast consuming all food Solution: Feed more frequently or use more flour per feeding.
- Hooch (dark liquid) on top
- Cause: Starter is very hungry Solution: Pour off hooch, feed starter. Increase feeding frequency.
Storage
Active starter at room temperature needs daily feeding. Refrigerate for weekly maintenance feeding. Keeps Indefinitely with proper care. Refrigerated starter needs to be fed and warmed up 1-2 days before baking. Can be dried or frozen for long-term backup.
Health Benefits
- Breaks down phytic acid for better mineral absorption
- Lower glycemic index than regular bread
- Easier to digest due to fermentation
- Contains beneficial organic acids
- May be tolerable for some with gluten sensitivity
- Longer shelf life naturally
Serving Suggestions
- Classic sourdough loaves
- Sourdough pizza dough
- Pancakes and waffles with discard
- Crackers from discard
- Sourdough cinnamon rolls
- Focaccia and flatbreads
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