makes bread · tools

Yeast → Sourdough Converter

Swap commercial yeast for ripe starter without wrecking the recipe’s hydration. Enter the yeast (and the flour, if you have it), and I’ll tell you how much starter to use and what to subtract from the flour and water. Timing still stretches — sourdough is slower than a packet of yeast. Every loaf on this site is already built on starter; use this when you’re adapting someone else’s yeasted formula. Pair it with the baker’s calculator once you have the spine of the dough.

Convert

Yeast type Yeast amount Unit Recipe flour g Recommended — unlocks % inoculation Recipe water g Optional — for adjusted bowl water Inoculation % Starter as % of flour; 15–25% is typical Starter hydration % 1:1:1 feed = 100%

Use this starter

What	Amount
Ripe starter to add
Flour inside that starter
Water inside that starter
Yeast (instant-equivalent)

Weigh into the bowl

The starter already brings flour and water. Subtract those so the dough’s hydration stays put.

Ingredient	Grams
Flour (after subtracting starter’s share)
Water (after subtracting starter’s share)
Ripe starter

Ripe starter g Starter hydration % Express as Unit

Approximate commercial yeast

What	Amount
Commercial yeast
Flour inside the starter
Water inside the starter

Instant : active dry : fresh ≈ 1 : 1.25 : 3 by weight. A US packet is 7 g. Starter strength varies — treat the result as a starting point, then watch the dough, not the clock. Need a starter first? See how I keep mine.