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Sourdough Starter Guide: Feeding Ratios and Maintenance

Food & Cooking · Guide · By DailyTools Editorial Team · August 1, 2026 · 2 min read

A healthy starter doubles in 4–8 hours after feeding at room temperature. Equal parts flour and water by weight is the standard 100% hydration baseline.

Guide illustration for sourdough starter feeding and maintenance

Food & Cooking

Sourdough starter is a culture of wild yeast and lactic acid bacteria in flour and water paste. You maintain it by regular feeding — fresh flour and water that microbes consume, producing CO₂ and acids that leaven and flavour bread. Ratios describe how much flour and water you add relative to existing starter.

100% hydration baseline

Most home starters run at 100% hydration: equal weights of flour and water at each feed (1:1:1 — starter : flour : water by weight). Example: discard to 50 g starter, add 50 g flour + 50 g water. The Sourdough Calculator scales feeds for your jar size and target rise volume.

Building from scratch

  1. Day 1: mix 50 g whole wheat or rye + 50 g water; cover loosely
  2. Days 2–7: discard half (or fixed amount), feed 1:1:1 daily
  3. When it doubles in 4–8 h and smells fruity-tangy, ready to bake
  4. May take 7–14 days depending on temperature and flour

Discard and refrigerator storage

Discard prevents exponential growth — use in pancakes, crackers, or compost. Refrigerated starter slows metabolism; feed weekly or refresh twice before baking day. Stiff starters (lower hydration) ferment slower; liquid starters (125%+ hydration) ferment faster with milder acidity.

Signs of health vs problems

  • Healthy: doubles predictably, bubbles throughout, pleasant sour aroma
  • Hungry: liquid hooch on top, acetone smell — pour hooch or stir in, feed
  • Contamination: pink/orange streaks, mould — discard and restart

Frequently asked questions

Do I need special flour?

Whole grain rye or wheat jump-starts microbes; AP flour works once established.

What is levain vs starter?

Levain is starter built in one feed specifically for a bake — often larger and peaked at mixing time.

Can I use tap water?

Usually yes; heavily chlorinated water may slow start — let sit overnight or use filtered.

How much starter in a recipe?

Typical breads use 15–25% levain relative to flour weight; the calculator helps scale from your jar.

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