How to Build 80g of 1:3:2 Semi-Stiff (67%) Sourdough Starter (13g Seed, 40g Flour, 27g Water)
Low-hydration stiff levain math (67% Semi-Stiff Levain) to build 80g of sweet, low-acidity starter for artisan bread or enriched dough.
There are exactly 6 parts in a 1:3:2 Semi-Stiff (67%) feed. At 80g that is 13.3g per part — 13g of it is the seed culture you already own, 40g is new flour and 27g is water. Expect a 8 - 10 hrs window to full dome at 75°F. The zero-discard version builds 100g (17g / 50g / 33g) so 20g always survives in the jar. Suits High-elasticity creamy crumb stiff levain build.
- Exact 80g Build
- 13g : 40g : 27gStarter : Flour : Water (1:3:2 Semi-Stiff (67%))
- 80g + 20g Jar Reserve
- 17g : 50g : 33gBuilds 100g total (0g discard waste)
- Estimated Peak Window
- 8 - 10 hrsAt 74°F–76°F (23.5°C–24.5°C)
- Levain Hydration
- 67%High-elasticity creamy crumb stiff levain build
Gram-by-Gram 1:3:2 Semi-Stiff (67%) Levain Breakdown for 80g (67% Semi-Stiff Levain)
Zero-waste gram breakdown for 1:3:2 Semi-Stiff (67%) (67% Semi-Stiff Levain) centred on the 80g target, with the 100g jar reserve alongside.
| Target Levain Yield | Seed Starter (1 Part) | Fresh Flour (3 Parts) | Water (2 Parts) | Peak Ripening Time @ 75°F |
|---|---|---|---|---|
| 70g target ([Target]) | seed 12g | flour 35g | water 23g | ripe in 8 - 10 hrs |
| 100g target (One Step Down) | seed 17g | flour 50g | water 33g | ripe in 8 - 10 hrs |
| 80g target (One Step Up) | seed 13g | flour 40g | water 27g | ripe in 8 - 10 hrs |
| 60g target (Two Steps Down) | seed 10g | flour 30g | water 20g | ripe in 8 - 10 hrs |
| 90g target (Two Steps Up) | seed 15g | flour 45g | water 30g | ripe in 8 - 10 hrs |
Dynamic Stoichiometric Workbench (13g : 40g : 27g)
Test custom loaf weights or alternative fermentation schedules directly against the 17g : 50g : 33g benchmark above.
How 1:3:2 Semi-Stiff (67%) Hydration Shifts Lactic-to-Acetic Fermentation in a 80g Build
Monod growth kinetics explain the 8 - 10 hrs window: the 1:3:2 Semi-Stiff (67%) refresh drops the seed fraction to 13.3g per 6 parts, so fermentable sugar concentration sits just above the half-saturation constant for 13g of inoculum. Yeast divides fastest while sugar is plentiful, then slows as the 40g of new flour is exhausted and lactic acid accumulates.
Scaling the refresh scales the acid dilution too. A 80g 1:3:2 Semi-Stiff (67%) build and a 100g build do not carry the same proportion of the previous batch's acid, because the extra 50g of flour and 33g of water dilute the 17g seed further — which is why the buffered version always tastes marginally milder.
Zero-Discard Scraping Method for 80g Levain (1:3:2 Semi-Stiff (67%))
- Reserve the 20g Jar Remainder (17g): Tip your starter jar and scrape every last gram into a clean vessel — roughly 17g — so nothing is discarded.
- Combine the 1:3:2 Semi-Stiff (67%) Feed (50g + 33g): Stir 50g of flour into 17g of seed, then add 33g of room-temperature water until no dry flour remains.
- Mark the 100g Target: Level the jar and tape a line at the starting height; the culture should dome well past it within 8 - 10 hrs at 75°F.
- Harvest 80g and Return 20g: Pour 80g of peaked levain into your dough, then scrape the surviving 20g back into the jar and refrigerate at 38°F.
Key Baker's Math Questions (Exact 80g Build: 13g : 40g : 27g)
What happens if I use 1:3:2 Semi-Stiff (67%) starter in a very wet dough?
The 67% Semi-Stiff Levain levain carries less acid, so a wet dough keeps more of its elasticity. Hold back a little extra water if your flour absorbs like 40g of bread flour does.
Why is my 1:3:2 Semi-Stiff (67%) starter not doubling?
Usually the seed was neglected in the refrigerator. Two warm 1:2:2 refreshes at 76–78°F, each with 40g of fresh flour, will strip the acid and restart the yeast.
Does the 80g figure include the jar remnants?
No. 80g is the usable sourdough culture you take out of the jar; the jar build is 100g so that 20g of culture always survives the transfer.