Precision Coffee Extraction and Chemistry
Explore the physical and chemical dynamics of specialty coffee brewing. Calibrate extractions using refractometry, manipulate mineral buffers in water, and decode fermentation and roast kinetics.
Like Duolingo, but for Precision Coffee Extraction and Chemistry. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
24 levels across 4 sections, about 48 minutes end to end, roughly 10 days at five minutes a day. It moves through Engineering the Extraction, Measurement and Sensory Calibration, The Solvent and the Grind, and The Chemistry of the Bean.
Free forever · No credit card · iPhone & Android

Key ideas in Precision Coffee Extraction and Chemistry
- Low-pressure saturation allows grounds to swell uniformly and eliminates dry pockets without triggering hydraulic fracturing
- Water naturally tracks along the smooth basket perimeter if puck resistance spikes before full saturation occurs
- Even wetting equalizes hydraulic resistance across the radius of the puck before high compressive pressure is applied
- Coffee pucks lose roughly 18-22% of dry mass during extraction, steadily decreasing internal hydraulic resistance
- Maintaining fixed pump pressure against an eroding puck causes flow velocity to spike, increasing astringent, late-stage extraction
- Tapering pressure down in the tail stabilizes the volumetric flow rate by matching the puck's decreasing resistance
- Coarser grind distributions prevent high-velocity fines from clogging the lower basket pores during high-flow extraction
- Brewing between 5 to 6 bar limits bed compaction, enabling high extraction uniformity in under 16 seconds
- Short contact times and wider interstitial channels prevent the localized micro-channeling common to ultrafine espresso pucks
- Polar, volatile organic acids dissolve and extract almost instantaneously during early bed wetting
- Simple sugars and mid-weight maillard aromatic compounds extract as the core body of the shot
- Lipids, polyphenols, and bitter chlorogenic acid breakdown products require sustained solvent flow to dislodge and wash out late
- Headspace volume directly controls how much room the dry coffee matrix has to expand during degassing and initial wetting
- Excessive headspace allows the upper bed to unconstrain and expand freely, breaking surface integrity and lowering peak hydraulic resistance
- Insufficient headspace forces the swelling puck against the dispersion screen prematurely, causing localized compacting and dense resistance points
- A broken stream introduces intense local agitation that churns the coffee bed rather than gently saturating it
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 Precision Coffee Extraction and Chemistry 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 does water tend to rush down the edges of the portafilter basket if high pressure hits an unsaturated puck?
Get it right to open this lesson and 23 more in the app.
Where Precision Coffee Extraction and Chemistry takes you
- 1
Engineering the Extraction
- Flow Profiling and Puck Dynamics in Espresso
- Percolation Physics and Slurry Dynamics in Pour-Over
- 2
Measurement and Sensory Calibration
- Quantitative Extraction Analysis with Refractometry
- Deconstructing Acid Profiles and Extraction Defects
- 3
The Solvent and the Grind
- Water Chemistry and Mineral Buffers
- Grind Particle Distribution and Burr Geometry
- 4
The Chemistry of the Bean
- Fermentation Biochemistry and Post-Harvest Processing
- Roast Kinetics and Thermal Degradation
4 sections · 8 units · 24 levels. Built to play, not to enroll.
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
Precision Coffee Extraction and Chemistry 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.
More Food & Drink on Tomo
Coffee Extraction, Chemistry, and Terroir
Master the physics of extraction, water mineral kinetics, fermentation biochemistry, and roast thermodynamics. Designed for experienced coffee professionals and passionate enthusiasts ready to move beyond the basics.
The Science of Specialty Coffee
Move beyond the basics of brewing to master the chemical and physical variables that define world-class coffee. Explore water chemistry, advanced extraction physics, and the complex biology of the coffee bean.
Advanced Espresso Extraction
Move beyond the basic double shot. Master the variables of flow, pressure, and chemistry to achieve professional-grade extraction and flavor clarity.
Coffee Extraction Dynamics
Move past standard brew ratios and dial in coffee with physical and chemical precision. Master flow profiling, mineral buffer manipulation, and kinetic extraction to systematically unlock complex roasts.
Precision Coffee Extraction
Move past standard recipes by mastering the physics and chemistry of coffee brewing. Control fluid dynamics, particle kinetics, and water ion balances to consistently extract peak flavor clarity.
Coffee: Dialing, Extraction, and Technique
Troubleshoot extraction flaws, master puck and bed physics, and engineer your water chemistry. Designed for experienced brewers looking to eliminate guesswork and achieve repeatable cup perfection.
Start Precision Coffee Extraction and Chemistry today.
Download Tomo, search Precision Coffee Extraction and Chemistry, and play your first lesson in under a minute.