Master Crumb

My Sourdough is Too Sour

Some people love tangy sourdough; others find it overwhelming. If your bread is too sour for your taste, you can adjust your process to produce a milder loaf while keeping all the benefits of natural fermentation.

What Makes Sourdough Sour?

The sour flavor comes from acids produced by lactic acid bacteria (LAB) in your starter:

  • Lactic acid – Milder, yogurt-like tang
  • Acetic acid – Sharper, vinegar-like tang

The ratio of these acids and total acidity determines how sour your bread tastes.

Factors That Increase Sourness

Long Fermentation

More time = more acid production. Both bulk fermentation and final proof contribute to sourness.

Cold Temperature

Cooler temperatures favor acetic acid production (the sharper, more vinegary tang). Long cold retards produce more sour bread.

Mature/Hungry Starter

A starter that's past its peak (hasn't been fed recently) is more acidic. Using it produces more sour bread.

Whole Grain Flour

Whole wheat and rye ferment faster and tend to produce more acid than white flour.

Stiff Starter

Lower hydration starters (stiffer consistency) produce more acetic acid than liquid starters.

How to Reduce Sourness

1. Shorten Fermentation Time

The most effective change. Reduce both bulk fermentation and final proof:

  • Shape when dough is 50% risen, not 75%
  • Final proof at room temp for shorter time
  • Avoid very long cold retards (keep under 12 hours)

2. Use Warmer Temperatures

Warmer fermentation favors yeast and lactic acid (milder) over acetic acid (sharper):

  • Keep dough at 24-27°C (75-80°F)
  • Use warmer water in your mix
  • Find a warm spot for fermentation

3. Use Young, Active Starter

Feed your starter and use it at its peak (doubled, not yet falling):

  • Feed 4-6 hours before mixing dough
  • Use when doubled but still domed
  • Never use starter that's fallen back or smells very acidic

4. Use Less Starter

Less starter = less acid and less acid-producing bacteria:

  • Try 10% starter instead of 20%
  • This extends fermentation but produces less acid overall

5. Use More White Flour

Replace some whole grain with bread flour or AP flour. Whole grains ferment faster and produce more acid.

6. Keep Starter at Room Temperature

Refrigerated starters develop more acetic acid. For milder bread:

  • Keep starter at room temperature
  • Feed twice daily if needed
  • Use while young and active

7. Skip or Shorten Cold Retard

Cold retard develops tang. For milder bread:

  • Final proof at room temperature
  • Bake same day
  • Or limit cold retard to 8 hours maximum

The Mildest Possible Sourdough

For very mild sourdough, combine several strategies:

  • Young starter (just peaked, 4-6 hours after feeding)
  • Low starter percentage (10%)
  • Warm fermentation (24-27°C)
  • Shorter bulk (until 50% rise)
  • Room temperature final proof (2-3 hours)
  • Mostly white flour

This produces bread with mild tang—still distinctly sourdough but not aggressively sour.

Is It Still Sourdough If It's Not Sour?

Yes! "Sourdough" refers to the leavening method (wild yeast and bacteria), not the flavor. Many traditional breads—like French pain au levain—are naturally leavened but quite mild.

The intensely sour San Francisco-style sourdough is just one expression of the style.

Starter Maintenance for Mild Bread

Keep your starter less acidic:

  • Feed frequently (once or twice daily at room temp)
  • Higher hydration starter (100% hydration or more)
  • Use mostly white flour for feedings
  • Keep warm (24°C/75°F)
  • Never let it go hungry (deflated, liquid on top)

Troubleshooting Extreme Sourness

If your bread is overwhelmingly sour despite adjustments:

Check Your Starter

  • Has it been neglected? Rebuild it with frequent feedings
  • Is it very old and acidic? Start fresh
  • Are you using it past peak? Time it better

Check Your Timing

  • Is bulk going too long? Stop earlier
  • Is cold retard exceeding 24 hours? Shorten it
  • Is your kitchen very warm? Adjust water temp

Finding Your Preference

Sourness is subjective. What's "too sour" for one person is "just right" for another. Experiment with these variables until you find your sweet spot. Keep notes on what you changed and how the bread tasted.