How to Feed a 1:1:1 Sourdough Starter Ratio to Make 90g (Same-Day 4 - 5 hrs Peak)
Fast same-day levain build math to make 90g of active starter (100% Liquid) using a 1:1:1 feeding ratio.
There are exactly 3 parts in a 1:1:1 feed. At 90g that is 30.0g per part — 30g of it is the seed culture you already own, 30g is new flour and 30g is water. Expect a 4 - 5 hrs window to full dome at 75°F. The zero-discard version builds 110g (37g / 37g / 36g) so 20g always survives in the jar. Suits Fast 4–5 hour same-day bake build.
- Exact 90g Build
- 30g : 30g : 30gStarter : Flour : Water (1:1:1)
- 90g + 20g Jar Reserve
- 37g : 37g : 36gBuilds 110g total (0g discard waste)
- Estimated Peak Window
- 4 - 5 hrsAt 74°F–76°F (23.5°C–24.5°C)
- Levain Hydration
- 100%Fast 4–5 hour same-day bake build
1:1:1 Sourdough Starter Feeding Chart Around a 90g Build
Zero-waste gram breakdown for 1:1:1 (100% Liquid) centred on the 90g target, with the 110g jar reserve alongside.
| Target Levain Yield | Seed Starter (1 Part) | Fresh Flour (1 Parts) | Water (1 Parts) | Peak Ripening Time @ 75°F |
|---|---|---|---|---|
| Levain build 80g ([Anchor]) | 27g cultured seed | 27g sifted flour + 26g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
| Levain build 110g (Down 10g) | 37g cultured seed | 37g sifted flour + 36g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
| Levain build 90g (Up 10g) | 30g cultured seed | 30g sifted flour + 30g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
| Levain build 70g (Down 20g) | 23g cultured seed | 23g sifted flour + 24g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
| Levain build 100g (Up 20g) | 33g cultured seed | 33g sifted flour + 34g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
Custom Batch Recalculation Engine
Fine-tune starter hydration between 50% stiff and 125% liquid while keeping your starter feeding ratio × target weight ratios locked.
Fast Same-Day Kinetics: Why a 1:1:1 Ratio Peaks in 4 - 5 hrs (90g Build)
Zero-waste feeding only works when the arithmetic is exact. The 90g build needs 30g of flour and 30g of water against 30g of seed; the 110g jar build needs 37g and 36g against 37g. Round to whole grams and the 20g reserve survives every cycle.
The practical limit of a 1:1:1 feed is handling, not biology. At 100% Liquid the 30g of water against 30g of flour produces a thick paste that clings to a spoon; at 1:1:1 it is a pourable batter. Choose the ratio that suits how you actually stir, not the one that sounds most professional.
Zero-Discard Scraping Method for 90g Levain (1:1:1)
- Check Room Temperature: Confirm your kitchen is close to 75°F (24°C). At 68°F a 1:1:1 feed stretches toward 4 - 5 hrs of extra ripening, and at 82°F it contracts noticeably.
- Build the 110g Base (37g Seed): Feed your seed starter with 37g of flour and 36g of water at 100% Liquid.
- Watch for the Convex Dome (4 - 5 hrs): The surface should bulge into a smooth pillow and jiggle when gently shaken, not collapse flat.
- Split the Peak (90 g Out, 20g Back): Use 90 g of the 110g build in your dough and restart the cycle with the 20g that is left.
Technical Q&A: How to Feed a 1:1:1 Sourdough Starter Ratio to M
Why is my 1:1:1 culture not doubling?
Usually the seed was neglected in the refrigerator. Two warm 1:2:2 refreshes at 76–78°F, each with 30g of fresh flour, will strip the acid and restart the yeast.
Is a 1:1:1 ratio too acidic for a 90g levain?
No. At 1:1:1 the acid from the previous batch is diluted across 1 parts of flour and 1 parts of water, giving a 100% liquid levain that tastes clean and mild.
How long can I keep the leftover starter in the fridge?
At 38°F (3°C) the 20g reserve rests indefinitely. Cold slows the culture without stopping it, and the 4 - 5 hrs peak simply arrives sooner once you feed it.