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 during early access · No credit card · iPhone & Android

Key ideas in Sourdough from Scratch
- The starter contains live wild yeast and bacteria
- Living organisms in the starter require regular maintenance to stay alive
- Unlike commercial dry yeast, a starter is a wet, active culture
- Flour provides the sugars and starches that the yeast colony eats
- Regular feeding prevents the colony from starving or becoming overly acidic
- Feeding 'refreshes' the activity level of the microbes
- Understanding that a starter is a living ecosystem requiring care rather than an inert ingredient
- Recognizing the purpose of feeding a starter
- Visible bubbles indicate carbon dioxide production by the yeast
- A pleasant, tangy, or fruity aroma is a sign of healthy fermentation
- Cold temperatures slow down the metabolism of the yeast and bacteria
- A significant increase in volume (rising) shows the starter has strength
- Identifying sensory cues for a healthy, active starter
- Keeping all the old starter would require exponentially more flour to feed it properly
- Discarding keeps the total volume of the starter manageable for home kitchens
- Applying the refrigerator 'pause' strategy for low-frequency baking
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.
Why can't you just leave a sourdough starter in the pantry for months without touching it?
Get it right to open this lesson and 8 more in the app.
Where Sourdough from Scratch takes you
Stop buying expensive loaves and start baking your own. Learn to keep a wild yeast 'pet' alive and turn three simple ingredients into professional-grade bread.
- 1
Meet Your Wild Yeast
- Keeping Your Starter Alive
- The First No-Knead Loaf
- 2
Mastering the Bake
- Reading the Dough's Mood
- The Magic of Heat and Steam
2 sections · 4 units · 9 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.
More Food & Drink on Tomo
Beyond the Label: Mastering Wine
Move past the basics and learn to decode complex flavors, pair like a pro, and navigate any wine list with confidence. Discover the hidden factors that make a great bottle stand out from the rest.
Mastering Your Morning Cup
Stop settling for bitter coffee and start brewing like a pro. Learn to fix your flavor, master the Moka Pot, and unlock the science behind the world's favorite bean.
Brewing Your Best Cup
Stop settling for mediocre coffee. Learn the simple, high-impact adjustments that turn your morning routine into a cafe-quality experience.
The Science and Craft of Coffee
Go beyond the basics of brewing to master the thermodynamics of roasting, the chemistry of extraction, and the complex microbiology of post-harvest processing.
Dialing In Your Coffee
Move beyond the recipe and learn to manipulate variables like a professional barista to find the 'sweet spot' in every bean.
Sourdough from Scratch
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.
Start Sourdough from Scratch today.
Download Tomo, search Sourdough from Scratch, and play your first lesson in under a minute.