How to Feed a 1:1:1 Sourdough Starter Ratio to Make 400g (Same-Day 4 - 5 hrs Peak)
Fast same-day levain build math to make 400g of active starter (100% Liquid) using a 1:1:1 feeding ratio.
A 400g 1:1:1 levain is 133g ripe culture plus 133g flour plus 134g water. Because a 1:1:1 ratio dilutes the previous batch's organic acid hard, this 100% Liquid culture peaks bright and clean in 4 - 5 hrs rather than tasting of vinegar. For a zero-waste routine, build 420g (140g / 140g / 140g) and return 20g to the fridge. Use it for Fast 4–5 hour same-day bake build.
- Exact 400g Build
- 133g : 133g : 134gStarter : Flour : Water (1:1:1)
- 400g + 20g Jar Reserve
- 140g : 140g : 140gBuilds 420g 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 380g to 420g
Zero-waste gram breakdown for 1:1:1 (100% Liquid) centred on the 400g target, with the 420g jar reserve alongside.
| Target Levain Yield | Seed Starter (1 Part) | Fresh Flour (1 Parts) | Water (1 Parts) | Peak Ripening Time @ 75°F |
|---|---|---|---|---|
| 380g 1:1:1 levain [Anchor] | 127g seed culture | 127g flour | 126g water | peak 4 - 5 hrs |
| 400g 1:1:1 levain Down 10g | 133g seed culture | 133g flour | 134g water | peak 4 - 5 hrs |
| 420g 1:1:1 levain Up 10g | 140g seed culture | 140g flour | 140g water | peak 4 - 5 hrs |
| 390g 1:1:1 levain Down 20g | 130g seed culture | 130g flour | 130g water | peak 4 - 5 hrs |
| 410g 1:1:1 levain Up 20g | 137g seed culture | 137g flour | 136g water | peak 4 - 5 hrs |
On-Bench Hydration & Fermentation Adjuster
Modify base flour mass, levain inoculation, or ambient kitchen temperature below to recalculate from this 133g : 133g : 134g baseline.
Fast Same-Day Kinetics: Why a 1:1:1 Ratio Peaks in 4 - 5 hrs (400g Build)
Flour quality matters more than ratio labels at this size: 133g of fresh flour feeding 133g 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.
Retard the leftover, not the levain. The 4 - 5 hrs peak at 100% Liquid is a room-temperature event; once you have used your 400g, park the remaining 20g of the 420g build in the refrigerator at 38°F, where the culture rests without consuming its own starch supply.
Zero-Discard Scraping Method for 400g Levain (1:1:1)
- Reserve the 20g Jar Remainder (140g): Tip your starter jar and scrape every last gram into a clean vessel — roughly 140g — so nothing is discarded.
- Combine the 1:1:1 Feed (140g + 140g): Stir 140g of flour into 140g of seed, then add 140g of room-temperature water until no dry flour remains.
- Mark the 420g 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 400g and Return 20g: Pour 400g of peaked sourdough culture into your dough, then scrape the surviving 20g back into the jar and refrigerate at 38°F.
Common Scaling & Troubleshooting Questions (133g : 133g : 134g)
Can I still make 400g if I only have 200g of culture?
Feed 200g of seed with 133g flour and 134g water, then treat the resulting 467g of levain as your culture instead.
How long does a 1:1:1 refreshing take to peak?
At 75°F (24°C) the culture domes in 4 - 5 hrs; a cooler room adds roughly 3.8% for every degree below that.
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.