Sourdough from Scratch
Like Duolingo, but for Sourdough from Scratch. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
For the part of you with thirty open tabs that never became anything.
A short one: 10 levels across 2 sections, about 20 minutes end to end, roughly 4 days at five minutes a day. It moves through The Living Loaf and From Dough to Crust. It starts from scratch.
Free forever · No credit card · iPhone & Android

Key ideas in Sourdough from Scratch
- The source of the microorganisms in a sourdough starter
- The purpose of feeding the starter
- Carbon dioxide bubbles trapped in the starter make it buoyant
- Heat speeds up the metabolism of yeast and bacteria
- A starter that sinks is either past its peak or not active enough to lift dough
- Cold temperatures significantly slow down the fermentation process
- How temperature dictates the pace of fermentation
- Without discarding, the amount of flour needed for each feeding would grow exponentially
- The Float Test as a readiness indicator
- Keeping the total volume small makes the starter easier to manage in a home kitchen
- Discarding ensures the ratio of fresh food to old starter remains high
- The necessity of discarding starter
- Flour needs time to fully hydrate to start gluten development
- Enzymes in the flour naturally soften the dough during this rest
- A rested dough is much easier to work with and less sticky
- The benefit of the autolyse rest period
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives Sourdough from Scratch the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
What is the primary biological reason we add fresh flour to a starter?
Get it right to open this lesson and 9 more in the app.
Where Sourdough from Scratch takes you
Stop buying yeast and start a lifelong partnership with a wild starter. Learn to bake crusty, tangy loaves using nothing but flour, water, and time.
- 1
The Living Loaf
- Your Starter: The Kitchen Pet
- The No-Knead Rhythm
- 2
From Dough to Crust
- Reading and Shaping the Dough
- The Magic of Steam and Heat
2 sections · 4 units · 10 levels. Built to play, not to enroll.
You pick the voice
Sourdough from Scratch is taught in the The Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
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Start Sourdough from Scratch today.
Download Tomo, search Sourdough from Scratch, and play your first lesson in under a minute.