Sourdough Starter Calculator
Your starter smuggles flour and water into the dough.
Work out Sourdough Starter. Your starter smuggles flour and water into the dough. Shows the working, not just the answer.
Feed at 1:5:5
250 g + 250 g
Peak in roughly 10 h 15 min at 21 °C · 600 g of starter after feeding
The flour and water already inside the starter count towards the dough. Ignoring them is the commonest reason a loaf billed as 70% hydration comes out wetter than expected — 200 g of 100% starter smuggles 100 g of each into the mix. Peak time roughly halves for every 8 °C warmer, and a larger feed ratio delays it because the inoculation is proportionally smaller. A 1:10:10 feed at 18 °C and a 1:2:2 at 26 °C are completely different schedules. Use the starter at peak, not at collapse. A starter that has domed and just begun to flatten has the most leavening power; one that has fallen has eaten its food and turned acidic, which weakens the gluten.
How the Sourdough Starter Calculator works
Feeding amounts for any ratio and hydration, plus what the starter contributes to the final dough. The flour and water inside the starter count towards the loaf, and that is where stated hydration usually goes wrong.
Also known as: how much flour and water to feed my starter · 1:5:5 sourdough feeding · levain build calculator · does starter count towards hydration
Not medical advice. This calculator gives a general estimate, not medical advice. It cannot account for your individual health, medical history, or medication. Talk to a qualified healthcare professional before acting on any result.
Frequently asked questions
How do I feed a starter at 1:5:5?
Take the flour weight inside your starter and add five times that in flour and five times in water. For 100 g of 100% starter — 50 g of flour inside it — that is 250 g each.
Does the starter count towards the dough's hydration?
Yes, and forgetting it is the commonest reason a loaf comes out wetter than expected. 200 g of 100% starter carries 100 g of flour and 100 g of water into the mix.
How long until my starter peaks?
Roughly four to five hours at 21 °C with a small feed, halving for every 8 °C warmer and stretching considerably with larger feed ratios.
Should I use the starter at peak or after it falls?
At peak. A domed starter just beginning to flatten has the most leavening power; a collapsed one has eaten its food and turned acidic, which weakens gluten.
What is a stiff starter?
One fed at less than 100% hydration, commonly 50 to 60%. It ferments more slowly, keeps longer between feeds and produces a milder, less acetic flavour.
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