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.
Free forever · No credit card · iPhone & Android

Key ideas in Sourdough from Scratch
- Wild yeast and bacteria are naturally present and alive
- Visible bubbles indicate carbon dioxide production
- Flour provides the necessary sugars for the microbes to eat
- A tangy, fruity, or yeasty smell is a sign of good fermentation
- The mixture is a self-sustaining ecosystem, not a chemical reaction
- A flat, liquid surface with no bubbles indicates dormancy or hunger
- Understanding that a starter is a living biological community requiring food
- Identifying the sensory signs of a healthy, ready-to-use starter
- Keeping all the old starter requires exponentially more flour to feed it
- Heat speeds up the metabolism of yeast
- Discarding prevents the jar from overflowing
- Refrigeration is the best way to 'pause' a starter for a week
- Using temperature to manage the timeline of starter activity
- Floating indicates the starter is full of trapped gas
- The practical purpose of discarding starter during the feeding process
- Sinking means the starter hasn't peaked or has already collapsed
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 happening inside the jar when you see a lot of visible bubbles?
Get it right to open this lesson and 11 more in the app.
Where Sourdough from Scratch takes you
Master the art of wild yeast baking. Learn to maintain a healthy starter and bake your first crusty, tangy loaf with minimal equipment.
- 1
The Living Loaf
- Keeping Your Starter Alive
- The No-Knead Method
- 2
Mastering the Bake
- Timing the Fermentation
- Heat, Steam, and Crust
2 sections · 4 units · 12 levels. Built to play, not to enroll.
You pick the voice
Sourdough from Scratch is taught in the The Bestie style: your friend who just gets it. 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.