Baking formulas and oven work
Levain Build Calculator
Work backward from a target levain weight and hydration to determine new flour and water additions around a known seed starter.
Set the levain endpoint first
A liquid levain from a known seed
Using target ripe levain of 300 g, target levain hydration of 100 %, seed starter used of 30 g, seed hydration of 100 % gives new flour to add of 135.0 g and new water to add of 135.0 g. Ferment until the chosen maturity cue rather than assuming that equal build weights mature on an identical schedule.
Seed composition belongs in the balance
A levain target includes the seed starter plus newly added flour and water. Crediting the seed composition prevents the build from overshooting both weight and hydration.
The target should describe ripe levain available to mix. Bowl residue or starter reserved for maintenance is a separate allowance.
Inoculation remains a schedule decision
Seed percentage changes fermentation speed and flavor development. This calculator balances composition but does not choose an inoculation for the schedule.
Carry the levain components into calculations that express maintenance feeds as ratios, measure levain flour against total flour and include levain in final hydration.
Balancing target levain components
Method basis: Target flour and water are reconstructed from hydration, then the seed starter’s known components are credited.
Build toward the mixing time
- Set the usable ripe-levain target.
- Describe target and seed hydration.
- Subtract seed flour and water.
Levain maturity and transfer
Usable target and jar reserve are different quantities.
Seed strength can matter more than a perfectly rounded gram.
The build equation does not select flour or ripening temperature.
Documenting the build
Retain seed source, build flour, water temperature, target hydration, mixing time, room temperature, and the cue used to call the levain ripe.
If a build is staged, calculate each stage from the actual retained weight entering the next one. Do not assume every gram from the earlier stage transfers cleanly.
A mature levain may lose a little mass through handling or drying. When production tolerances are tight, add a modest explicit residue allowance to the target rather than altering hydration.
Use the calculated flour and water in the overall formula ledger. Otherwise the levain may be correct by itself while final dough hydration and flour percentages remain wrong.
Levain-build questions
Why can an addition show zero?
The seed already supplies at least the target amount of that component; choose a larger target or compatible hydration.
Is starter left in the jar part of the target?
Only if you deliberately include that reserve. Production levain and maintenance seed are clearer as separate builds.
Can a stiff seed make a liquid levain?
Yes, provided enough water is added and the target is large enough.
What if the seed weight is larger than the target?
Reduce the seed or increase the target. A build cannot remove flour or water already present in the seed.