Food & DrinkThe BestieAdvanced
Coffee Extraction and Tasting, a free food & drink course on Tomo

Coffee Extraction and Tasting

Master professional cupping protocols, dial in modern espresso ratios, and engineer precise extractions. Explore water chemistry, milk physics, and sensory analysis to unlock elite-level coffee craft.

Like Duolingo, but for Coffee Extraction and Tasting. 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 Dialing and Extraction Dynamics, Sensory Analysis and Palate Calibration, The Architecture of Espresso Drinks, and Underlying Chemistry: Water and Terroir.

24 bite-size levelsAbout 5 minutes each

Free forever · No credit card · iPhone & Android

Cupper Carl, the guide who teaches the Coffee Extraction and Tasting course
Coffee Extraction and Tasting
with Cupper Carl
24
Levels
4
Sections
5
Min/day
What you'll learn

Key ideas in Coffee Extraction and Tasting

  • Light-roast, high-altitude coffees have intact cellular matrix structures requiring higher solvent volume to extract pleasant sugars and tame sharp malic acidity
  • Darker roasts break down cell walls and become highly porous, making soluble material extract readily while risking over-extraction of bitter, roasty phenolics at long yields
  • Brew time is an output variable reflecting bed resistance, not a quality parameter that guarantees good cup balance on its own
  • Sensory balance dictates whether grind changes are necessary; if extraction balance and taste are optimal, an atypical contact time does not require correction
  • High pressure (9 bar) combined with fine grinds compresses the bed into an impermeable mass that causes localized micro-channeling
  • Coarsening the grind and reducing pressure to 5–6 bar stabilizes bed permeability, achieving high and uniform extraction efficiency at rapid shot speeds (12–16 seconds)
  • As soluble mass erodes throughout the shot, puck structural integrity decreases and water finds paths of least resistance faster
  • Maintaining flat 9 bar pressure against an eroding puck drives fines into bottom screen pores (fines migration) and cracks the bed, accelerating bitter, astringent over-extraction
  • Bottom paper filters prevent espresso basket holes from getting clogged by fines, drastically increasing flow rate at the periphery and enabling a finer grind
  • Deep needle distribution (WDT with 0.25–0.4mm needles) breaks up agglomerates and evens bulk density, eliminating void-induced micro-channels
  • Puck prep tools increase overall extraction ceiling and average total dissolved solids (TDS) rather than slowing down shot time
  • TDS measures concentration of dissolved solids in the cup, whereas EY measures the percentage of dry coffee mass pulled out into the brew
  • A high TDS can coexist with a severely under-extracted EY if high dose/short ratio limits overall solubles dissolution
  • Coarsening grind slightly while lengthening the brew ratio (more water per gram of coffee) extracts deeper into the bean mass while diluting the high TDS
  • Fines lack internal pore structure and dissolve almost instantaneously, migrating to form an impermeable cake layer that sets hydraulic backpressure
  • Large boulder cores require time-dependent diffusive extraction; if the brew finishes before hot water diffuses into the core, vegetal notes persist
Why not just Google it

You've tried the other tabs

Wikipedia

Thirty open tabs. Four facts you actually kept.

YouTube

You watched. You nodded. By Sunday it was gone.

ChatGPT

One answer, then back to scrolling.

Online courses

Eight weeks. You meant to finish. You didn't.

Tomo gives Coffee Extraction and Tasting 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.

Try a question

Here's what playing it feels like

A real question from this course. Take your best guess.

Dialing Espresso by Bean Density

Why do darker roasts usually taste better pulled at a shorter brew ratio like 1:1.5?

Get it right to open this lesson and 23 more in the app.

Course map

Where Coffee Extraction and Tasting takes you

  1. 1

    Dialing and Extraction Dynamics

    • Dialing Modern Espresso Ratios
    • Filter Extraction and Flow Physics
  2. 2

    Sensory Analysis and Palate Calibration

    • Professional Cupping Protocols
    • Diagnosing Roasting and Green Defects
  3. 3

    The Architecture of Espresso Drinks

    • Milk Physics and Microfoam Chemistry
    • Espresso Drink Taxonomy and Balance
  4. 4

    Underlying Chemistry: Water and Terroir

    • Water Chemistry and Solute Extraction
    • Origin, Processing, and Bean Solubility

4 sections · 8 units · 24 levels. Built to play, not to enroll.

New

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How it's taught

You pick the voice

This course
The Bestie

Coffee Extraction and Tasting is taught in 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 Coffee Extraction and Tasting today.

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