Any loaf count, any hydration, timed backwards from the bake.
You know the formula. What you keep redoing is the arithmetic: three loaves this time, 900 g each, 78% hydration, 20% levain at 100%, and the levain has to be ripe at 4 pm so the bread comes out at noon tomorrow. This does all of it in one screen.
WHAT IT WORKS OUT
- Grams of every flour in your blend, water, ripe levain and salt, with the flour and water inside the levain accounted for
- The levain build: seed starter, flour and water at your ratio, with spare for the jar
- Water temperature for your target dough temperature from room, flour and levain temperatures (friction factor for mixers)
- A schedule backwards from the bake: levain build, autolyse, mix, four folds, shape, cold proof, preheat, bake, each with a clock time
- Warnings when the hydration is slack for the flour, the levain is fast, or the water would be too hot
THE FERMENTATION MODEL
- Tell it the bulk time that works for you at a known dough temperature. It rescales that for the dough temperature you are targeting (Q10 of 2.5), your levain percentage and the whole-grain share of the blend
- Flour absorption: whole wheat, rye, spelt and the rest each pull the effective hydration up or down, and it tells you the number that gives the feel you want
- Bake day, live: tick "I have mixed", type the dough temperature off the probe and the kitchen temperature, and the rest of the day re-plans: new end of bulk, new fold times, earliest bake
Recipe book
Save each formula. Reopen, change the loaf count, done. Metric grams; °C or °F.
Who it's for
Home sourdough bakers who scale up for friends, bake on a schedule, or just want to stop doing the maths on the back of a flour bag.
What you get
- The scaler (one .html file, runs in any browser, offline)
- A 2-page quick-start guide
Good to know
- One file. No install, no account, no subscription, no internet needed after download.
- Your data stays on your computer. Export a backup any time; import it on another machine.
- Works on Mac, Windows, Linux and iPad (open the file in Safari or Chrome).
- Instant download.
What's inside the download
- Sourdough-Formula-Scaler.html
- Quick-Start-Guide.pdf
Made by Matthew Busel, a one-person studio in Tuckahoe, NY. About me. Questions: support@tensorust.com.
Food and drink
Sourdough Formula Scaler
any loaf count, levain build, water temperature, schedule backwards from the bake
Baker's percentages and loaf count in. Grams for every flour, water, levain and salt out, the levain build, the water temperature for your target dough temp, and a schedule backwards from the bake with bulk time rescaled for dough temperature, levain and whole grains. On bake day, type the real dough temperature and it re-predicts the end of bulk.
Works or I fix it. If a file doesn't open or work as described, email support@tensorust.com within 30 days and I fix it or send a working copy. All sales are final, so check the screenshots or ask first.
- Updated
- Oct 2026
- File
- ZIP, 213 KB: 1 HTML app, 1 PDF
- Who it's for
- Home sourdough bakers who scale up for friends, bake on a schedule, or just want to stop doing the maths on the back of a flour bag.
One-time price in US dollars, checkout by Stripe. After paying you land on a page with your download link. Each link works for 15 minutes, and reopening that page makes fresh ones.
- Sourdough-Formula-Scaler.zip