How to Build 400g of 1:2:1 Stiff (50%) Sourdough Starter (100g Seed, 200g Flour, 100g Water)
Low-hydration stiff levain math (50% Stiff Lievito Madre) to build 400g of sweet, low-acidity starter for artisan bread or enriched dough.
There are exactly 4 parts in a 1:2:1 Stiff (50%) feed. At 400g that is 100.0g per part — 100g of it is the seed culture you already own, 200g is new flour and 100g is water. Expect a 6 - 8 hrs window to full dome at 75°F. The zero-discard version builds 420g (105g / 210g / 105g) so 20g always survives in the jar. Suits Italian Lievito Madre / Panettone low-acid stiff build.
- Exact 400g Build
- 100g : 200g : 100gStarter : Flour : Water (1:2:1 Stiff (50%))
- 400g + 20g Jar Reserve
- 105g : 210g : 105gBuilds 420g total (0g discard waste)
- Estimated Peak Window
- 6 - 8 hrsAt 74°F–76°F (23.5°C–24.5°C)
- Levain Hydration
- 50%Italian Lievito Madre / Panettone low-acid stiff build
400g 1:2:1 Stiff (50%) Feeding Neighbourhood: Seed, Flour, Water & Peak Window
Neighbourhood of 1:2:1 Stiff (50%) builds used to sanity-check a scaled recipe before committing flour to the mixer.
| Levain Yield | Culture (1) | Feed Flour (2) | Feed Water (1) | Estimated Peak Window |
|---|---|---|---|---|
| 400g 1:2:1 Stiff (50%) levain [Target] | 100g seed culture | 200g flour | 100g water | peak 6 - 8 hrs |
| 410g 1:2:1 Stiff (50%) levain One Step Down | 103g seed culture | 205g flour | 102g water | peak 6 - 8 hrs |
| 390g 1:2:1 Stiff (50%) levain One Step Up | 98g seed culture | 195g flour | 97g water | peak 6 - 8 hrs |
| 420g 1:2:1 Stiff (50%) levain Two Steps Down | 105g seed culture | 210g flour | 105g water | peak 6 - 8 hrs |
| 380g 1:2:1 Stiff (50%) levain Two Steps Up | 95g seed culture | 190g flour | 95g water | peak 6 - 8 hrs |
Dynamic Stoichiometric Workbench (100g : 200g : 100g)
Test custom loaf weights or alternative fermentation schedules directly against the 105g : 210g : 105g benchmark above.
How 1:2:1 Stiff (50%) Hydration Shifts Lactic-to-Acetic Fermentation in a 400g Build
Scaling to 400g means every gram is shared across 4 parts (100.0g each). The 100g seed portion carries the entire wild yeast and lactobacilli population, the 200g flour portion supplies the substrate, and the 100g water portion sets the mobile phase for both.
Watch the jar wall. A 400g build in a straight-sided container rises almost exactly in proportion to its weight because 50% Stiff Lievito Madre levain traps little gas structure; mark the starting line with a rubber band and you can read the 6 - 8 hrs window without guessing.
Zero-Discard Scraping Method for 400g Levain (1:2:1 Stiff (50%))
- Divide 400g by 4 Parts (100.0g Each): A 1:2:1 Stiff (50%) ratio has 4 parts, so each part of your 400g target weighs 100.0g.
- Measure the 1 Seed Part (100g): That is your existing culture, weighed cold and fresh from the refrigerator.
- Measure the 2 Flour Part (200g) and 1 Water Part (100g): 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 400g and keep the balance as tomorrow's seed.
Key Baker's Math Questions (Exact 400g Build: 100g : 200g : 100g)
Does the 400 grams figure include the jar remnants?
No. 400 grams is the usable levain you take out of the jar; the jar build is 420g so that 20g of culture always survives the transfer.
Why is my 1:2:1 Stiff (50%) starter not doubling?
Usually the seed was neglected in the refrigerator. Two warm 1:2:2 refreshes at 76–78°F, each with 200g of fresh flour, will strip the acid and restart the yeast.
Why does my 1:2:1 Stiff (50%) sourdough culture smell sour instead of sweet?
Sourness means the seed was over-acidic going in. Feed 200g of fresh flour against 100g of the old starter twice in a row at 78°F and the taint disappears.