How to Feed a 1:1:1 Sourdough Starter Ratio to Make 100g (Same-Day 4 - 5 hrs Peak)
Fast same-day levain build math to make 100g of active starter (100% Liquid) using a 1:1:1 feeding ratio.
A 100g 1:1:1 levain is 33g ripe starter plus 33g flour plus 34g 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 120g (40g / 40g / 40g) and return 20g to the fridge. Use it for Fast 4–5 hour same-day bake build.
- Exact 100g Build
- 33g : 33g : 34gStarter : Flour : Water (1:1:1)
- 100g + 20g Jar Reserve
- 40g : 40g : 40gBuilds 120g 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
Reference Table: 1:1:1 Ratios at 100g and Its Neighbours
Weights derived from the 3-part 1:1:1 division, where one part equals 33.3g.
| How Much to Make | Starter (1 Part) | Flour (1 Parts) | Water (1 Parts) | Peak Hours (75°F) |
|---|---|---|---|---|
| 100g 1:1:1 ([Anchor]) | seed 33g | fresh flour 33g | room-temp water 34g | peak 4 - 5 hrs at 75°F |
| 90g 1:1:1 (Down 10g) | seed 30g | fresh flour 30g | room-temp water 30g | peak 4 - 5 hrs at 75°F |
| 110g 1:1:1 (Up 10g) | seed 37g | fresh flour 37g | room-temp water 36g | peak 4 - 5 hrs at 75°F |
| 80g 1:1:1 (Down 20g) | seed 27g | fresh flour 27g | room-temp water 26g | peak 4 - 5 hrs at 75°F |
| 120g 1:1:1 (Up 20g) | seed 40g | fresh flour 40g | room-temp water 40g | peak 4 - 5 hrs at 75°F |
Real-Time Dough & Starter Scaling Sandbox
Scale this 1:1:1 (1 1 1) Sourdough Starter Rati specification up or down on your digital scale with zero hydration drift.
Fast Same-Day Kinetics: Why a 1:1:1 Ratio Peaks in 4 - 5 hrs (100g Build)
Monod growth kinetics explain the 4 - 5 hrs window: the 1:1:1 feed drops the seed fraction to 33.3g per 3 parts, so fermentable sugar concentration sits just above the half-saturation constant for 33g of inoculum. Yeast divides fastest while sugar is plentiful, then slows as the 33g of new flour is exhausted and lactic acid accumulates.
Scaling the feed scales the acid dilution too. A 100g 1:1:1 build and a 120g build do not carry the same proportion of the previous batch's acid, because the extra 40g of flour and 40g of water dilute the 40g seed further — which is why the buffered version always tastes marginally milder.
Zero-Discard Scraping Method for 100g Levain (1:1:1)
- Reserve the 20g Jar Remainder (40g): Tip your starter jar and scrape every last gram into a clean vessel — roughly 40g — so nothing is discarded.
- Combine the 1:1:1 Feed (40g + 40g): Stir 40g of flour into 40g of seed, then add 40g of room-temperature water until no dry flour remains.
- Mark the 120g 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 100g and Return 20g: Pour 100g of peaked levain into your dough, then scrape the surviving 20g back into the jar and refrigerate at 38°F.
Diagnostic Answers: 1:1:1 (1 1 1) Sourdough Starter Ratio for 10
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.
Why does my 1:1:1 levain smell sour instead of sweet?
Sourness means the seed was over-acidic going in. Feed 33g of fresh flour against 33g of the old starter twice in a row at 78°F and the taint disappears.
How many grams of starter, flour and water make 100g at a 1:1:1 ratio?
33g starter + 33g flour + 34g water = 100g, split across 3 parts of 33.3g each.