How to Feed a 1:2:2 Sourdough Starter Ratio to Make 30g (Same-Day 6 - 8 hrs Peak)
Fast same-day levain build math to make 30g of active starter (100% Liquid) using a 1:2:2 feeding ratio.
There are exactly 5 parts in a 1:2:2 feed. At 30g that is 6.0g per part — 6g of it is the seed culture you already own, 12g is new flour and 12g is water. Expect a 6 - 8 hrs window to full dome at 75°F. The zero-discard version builds 50g (10g / 20g / 20g) so 20g always survives in the jar. Suits Balanced 6–8 hour morning levain build.
- Exact 30g Build
- 6g : 12g : 12gStarter : Flour : Water (1:2:2)
- 30g + 20g Jar Reserve
- 10g : 20g : 20gBuilds 50g 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
30g 1:2:2 Feeding Neighbourhood: Seed, Flour, Water & Peak Window
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 20g ([Anchor]) | 4g cultured seed | 8g sifted flour + 8g liquid | zero-waste reserve 20g | 6 - 8 hrs dome window |
| Levain build 50g (Down 10g) | 10g cultured seed | 20g sifted flour + 20g liquid | zero-waste reserve 20g | 6 - 8 hrs dome window |
| Levain build 30g (Up 10g) | 6g cultured seed | 12g sifted flour + 12g liquid | zero-waste reserve 20g | 6 - 8 hrs dome window |
| Levain build 20g (Down 20g) | 4g cultured seed | 8g sifted flour + 8g liquid | zero-waste reserve 20g | 6 - 8 hrs dome window |
| Levain build 40g (Up 20g) | 8g cultured seed | 16g sifted flour + 16g 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 (30g Build)
Flour quality matters more than ratio labels at this size: 12g of fresh flour feeding 6g of seed at 100% Liquid determines how much maltose the amylase releases per hour, which in turn sets the 6 - 8 hrs ripening curve at 75°F.
The practical limit of a 1:2:2 feed is handling, not biology. At 100% Liquid the 12g of water against 12g 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 30g Levain (1:2:2)
- Divide 30 g by 5 Parts (6.0g Each): A 1:2:2 ratio has 5 parts, so each part of your 30 g target weighs 6.0g.
- Measure the 1 Seed Part (6g): That is your existing culture, weighed cold and fresh from the refrigerator.
- Measure the 2 Flour Part (12g) and 2 Water Part (12g): Add both, mix to a stiff paste, and cover the jar.
- Peak and Reserve (6 - 8 hrs): After 6 - 8 hrs at 75°F, portion out 30 g and keep the balance as tomorrow's seed.
Diagnostic Answers: 1:2:2 (1 2 2) Sourdough Starter Ratio for 30
Why does my 1:2:2 levain smell sour instead of sweet?
Sourness means the seed was over-acidic going in. Feed 12g of fresh flour against 6g of the old starter twice in a row at 78°F and the taint disappears.
Can I scale this 30g build up to 60g?
Double every number: 12g starter, 24g flour, 24g water. The ratio, and therefore the 6 - 8 hrs peak, is unchanged.
What is the real difference between 1:2:2 and a 1:1:1 feed?
A 1:1:1 feed keeps one third of the batch as seed and peaks fastest; 1:2:2 keeps one 5th, so it ripens more slowly but with far less inherited acidity.