The Art of the Dial-In
Move beyond following recipes to understanding the variables of extraction. Learn to diagnose flavor profiles and manipulate water, heat, and grind to brew the perfect cup every time.
Like Duolingo, but for The Art of the Dial-In. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
A short one: 14 levels across 2 sections, about 28 minutes end to end, roughly 6 days at five minutes a day. It moves through Diagnosing the Cup and Precision Variables. It assumes you already know the basics.
Free forever · No credit card · iPhone & Android
Key ideas in The Art of the Dial-In
- Acids dissolve first, so sourness means the water didn't extract enough sugars
- Under-extraction occurs when the brew time is too short for the coffee type
- Over-extraction pulls out heavy polyphenols that cause a dry mouthfeel
- Bitterness and ashiness are the final flavors to emerge during a long brew
- Identifying under-extraction through sensory cues
- Recognizing the physical sensation of over-extraction
- Bypass involves adding clean hot water to the finished brew to lower concentration
- Finer grinds increase surface area to speed up extraction and add sweetness
- Adding water post-brew changes strength without extracting bitter tannins
- Coarser grinds slow down extraction to prevent bitter flavors from dominating
- Using grind size to correct flavor imbalances
- Higher temperatures increase the energy available to extract stubborn sugars
- Applying the bypass technique to fix intensity
- Temperature is a secondary lever used for micro-adjustments after the grind is set
- Identifying when to use temperature as a fine-tuning tool
- Acids and fats dissolve first
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 The Art of the Dial-In 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.
If your coffee tastes unpleasantly sharp and sour, what is the most likely chemical explanation?
Get it right to open this lesson and 13 more in the app.
How to learn The Art of the Dial-In, step by step
Go in order. 14 short levels across 2 sections, about 28 minutes in all, five minutes a day.
- 1
Diagnosing the Cup
- Saving a Bad Brew
- The Extraction Spectrum
- 2
Precision Variables
- Water Chemistry and Heat
- Agitation and Flow Control
- The Recipe Framework
2 sections · 5 units · 14 levels. Built to play, not to enroll.
Questions about The Art of the Dial-In
How do I learn The Art of the Dial-In?
Go in order: start with Diagnosing the Cup, then Precision Variables. On Tomo that's 14 short levels, about 28 minutes in all, played five minutes a day. Start free and play the first level in under a minute.
Is there a Duolingo-style app for The Art of the Dial-In?
Yes. Tomo works like Duolingo: short daily lessons, streaks and quick quizzes. The Art of the Dial-In is one of its free courses, and you can type any other topic to get a course of your own.
Is The Art of the Dial-In free?
Yes. The Art of the Dial-In is playable on Tomo's free plan, which doesn't expire. No credit card, no waitlist. Download the app and start your first lesson.
How long does it take to learn The Art of the Dial-In?
14 levels across 2 sections, about 28 minutes of play in total. It's built for five minutes a day, so you finish it a little at a time instead of all at once.
Do I need any background to start The Art of the Dial-In?
No. It's pitched at an intermediate level, so it starts where you are and builds up. If you can tap a phone, you can start.
Tomo is in ChatGPT
Tomo is also a ChatGPT plugin: the same playable courses, built and played inside your chat.
Add Tomo to ChatGPT- What to ask
- “Make me a Tomo course on black holes.” “Turn this chat into a Tomo course.”
- What you get
- Quick questions with instant feedback, hearts and stars, ready to play in about a minute.
- Where it goes
- No sign-up to start. Connect your Tomo account and your streak carries on in the app.
You pick the voice
The Art of the Dial-In is taught in 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.
More Food & Drink on Tomo
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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.
Better Coffee at Home
Stop settling for mediocre mornings. Learn to brew cafe-quality coffee by mastering the variables that actually matter, from bean selection to extraction science.
Dialing In Better Coffee
Move beyond following rigid recipes and learn how extraction mechanics shape every cup. Diagnose sour or bitter off-notes, tune your grind and flow, and brew coffee with intention.
The Professional Barista
Move beyond basic brewing to master the precision, chemistry, and workflow of a high-end specialty coffee bar.
Start The Art of the Dial-In today.
Download Tomo, search The Art of the Dial-In, and play your first lesson in under a minute.