How to Feed a 1:2:2 Sourdough Starter Ratio to Make 180g (Same-Day 6 - 8 hrs Peak)
Fast same-day levain build math to make 180g of active starter (100% Liquid) using a 1:2:2 feeding ratio.
To make 180g of active starter at a 1:2:2 ratio (1:2:2), weigh 36g of ripe seed, 72g of flour and 72g of water. That 100% Liquid culture will be domed and sweet in 6 - 8 hrs at 75°F, which is exactly the timing you want for Balanced 6–8 hour morning levain build. Feed 200g — 40g / 80g / 80g — if you want to stop discarding permanently.
- Exact 180g Build
- 36g : 72g : 72gStarter : Flour : Water (1:2:2)
- 180g + 20g Jar Reserve
- 40g : 80g : 80gBuilds 200g total (0g discard waste)
- Estimated Peak Window
- 6 - 8 hrsAt 74°F–76°F (23.5°C–24.5°C)
- Levain Hydration
- 100%Balanced 6–8 hour morning levain build
Scaling 1:2:2 Feeds Across 160g to 200g
Peak ripening estimates assume a 75°F kitchen and 23°C room; colder kitchens need roughly 3.8% more time per degree.
| Build This Much | Seed (1 Part) | Flour (2 Parts) | Water (2 Parts) | Ripening Time |
|---|---|---|---|---|
| Levain build 180g ([Target]) | 36g cultured seed | 72g sifted flour + 72g liquid | zero-waste reserve 20g | 6 - 8 hrs dome window |
| Levain build 190g (One Step Down) | 38g cultured seed | 76g sifted flour + 76g liquid | zero-waste reserve 20g | 6 - 8 hrs dome window |
| Levain build 170g (One Step Up) | 34g cultured seed | 68g sifted flour + 68g liquid | zero-waste reserve 20g | 6 - 8 hrs dome window |
| Levain build 200g (Two Steps Down) | 40g cultured seed | 80g sifted flour + 80g liquid | zero-waste reserve 20g | 6 - 8 hrs dome window |
| Levain build 160g (Two Steps Up) | 32g cultured seed | 64g sifted flour + 64g liquid | zero-waste reserve 20g | 6 - 8 hrs dome window |
Real-Time Dough & Starter Scaling Sandbox
Scale this 1:2:2 (1 2 2) Sourdough Starter Rati specification up or down on your digital scale with zero hydration drift.
Fast Same-Day Kinetics: Why a 1:2:2 Ratio Peaks in 6 - 8 hrs (180g Build)
Temperature and ratio interact. The 1:2:2 figure of 1:2:2 does not mean the same thing in a 68°F kitchen as in an 82°F one: with the 6 - 8 hrs window quoted at 75°F, a cooler room stretches it by roughly 3.8% per degree, so 72g of flour in a 100% Liquid feed may need longer than the label implies.
Hydration discipline at 100% Liquid means the 72g of water should be room temperature, not hot. Water above 95°F can shock the lactobacilli and stall the 6 - 8 hrs peak, while water below 60°F pushes fermentation into a slow acidifying phase that flattens the eventual rise.
Zero-Discard Scraping Method for 180g Levain (1:2:2)
- Check Room Temperature: Confirm your kitchen is close to 75°F (24°C). At 68°F a 1:2:2 feed stretches toward 6 - 8 hrs of extra ripening, and at 82°F it contracts noticeably.
- Build the 200g Base (40g Seed): Feed your seed starter with 80g of flour and 80g of water at 100% Liquid.
- Watch for the Convex Dome (6 - 8 hrs): The surface should bulge into a smooth pillow and jiggle when gently shaken, not collapse flat.
- Split the Peak (180g Out, 20g Back): Use 180g of the 200g build in your dough and restart the cycle with the 20g that is left.
Diagnostic Answers: 1:2:2 (1 2 2) Sourdough Starter Ratio for 18
Should the water be warm or cold for a 1:2:2 feed?
Room temperature, roughly 70°F (21°C). Hotter water risks shocking the culture, while colder water stretches the 6 - 8 hrs peak considerably.
How much extra should I build so I never run out of starter?
Build 200g in total — 40g starter, 80g flour, 80g water — and the leftover 20g becomes the seed for the next feed.
Why does my 1:2:2 levain smell sour instead of sweet?
Sourness means the seed was over-acidic going in. Feed 72g of fresh flour against 36g of the old starter twice in a row at 78°F and the taint disappears.