How to Feed a 1:1:1 Sourdough Starter Ratio to Make 120g (Same-Day 4 - 5 hrs Peak)
Fast same-day levain build math to make 120g of active starter (100% Liquid) using a 1:1:1 feeding ratio.
Want 120 grams of active levain and zero waste? Mix 40g of your existing culture with 40g flour and 40g water — a 1:1:1 ratio at 100% Liquid. Fed at 75°F the starter peaks in 4 - 5 hrs and smells sweet rather than sour. Scale up to 140g (47g seed, 47g flour, 46g water) and the extra 20g stays in the jar as tomorrow's seed. Ideal for Fast 4–5 hour same-day bake build.
- Exact 120g Build
- 40g : 40g : 40gStarter : Flour : Water (1:1:1)
- 120g + 20g Jar Reserve
- 47g : 47g : 46gBuilds 140g 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
Scaling 1:1:1 Feeds Across 100g to 140g
Zero-waste gram breakdown for 1:1:1 (100% Liquid) centred on the 120g target, with the 140g jar reserve alongside.
| Target Levain Yield | Seed Starter (1 Part) | Fresh Flour (1 Parts) | Water (1 Parts) | Peak Ripening Time @ 75°F |
|---|---|---|---|---|
| Levain build 120g ([Baseline]) | 40g cultured seed | 40g sifted flour + 40g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
| Levain build 130g (Trimmed Read) | 43g cultured seed | 43g sifted flour + 44g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
| Levain build 110g (Extended Read) | 37g cultured seed | 37g sifted flour + 36g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
| Levain build 140g (Compact Read) | 47g cultured seed | 47g sifted flour + 46g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
| Levain build 100g (Generous Read) | 33g cultured seed | 33g sifted flour + 34g liquid | zero-waste reserve 20g | 4 - 5 hrs dome window |
Live Parameter Solver for How to Feed a 1:1:1 Sourdough Starter Rati
Dial in custom baker's percentages and export your adjusted 40g : 40g : 40g formula for bake day.
Fast Same-Day Kinetics: Why a 1:1:1 Ratio Peaks in 4 - 5 hrs (120g Build)
Flour quality matters more than ratio labels at this size: 40g of fresh flour feeding 40g of seed at 100% Liquid determines how much maltose the amylase releases per hour, which in turn sets the 4 - 5 hrs ripening curve at 75°F.
Flour choice shifts the timeline more than most bakers expect. At 1:1:1 with 40g of flour, a malted bread flour peaks faster and sweeter than an unmalted one, because the added amylase liberates more maltose per minute and the culture simply runs out of substrate sooner.
Zero-Discard Scraping Method for 120g Levain (1:1:1)
- Reserve the 20g Jar Remainder (47g): Tip your starter jar and scrape every last gram into a clean vessel — roughly 47g — so nothing is discarded.
- Combine the 1:1:1 Feed (47g + 46g): Stir 47g of flour into 47g of seed, then add 46g of room-temperature water until no dry flour remains.
- Mark the 140g Target: Level the jar and tape a line at the starting height; the culture should dome well past it within 4 - 5 hrs at 75°F.
- Harvest 120g and Return 20g: Pour 120g of peaked levain into your dough, then scrape the surviving 20g back into the jar and refrigerate at 38°F.
Cereal Chemistry & Bench Execution FAQs
Why does my 1:1:1 levain smell sour instead of sweet?
Sourness means the seed was over-acidic going in. Feed 40g of fresh flour against 40g of the old starter twice in a row at 78°F and the taint disappears.
What happens if I use 1:1:1 starter in a very wet dough?
The 100% Liquid levain carries less acid, so a wet dough keeps more of its elasticity. Hold back a little extra water if your flour absorbs like 40g of bread flour does.
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 40g of fresh flour, will strip the acid and restart the yeast.