Espresso Calibration Morning
Coffee: Ethiopia Guji Karume
Process: Natural
Batch: 250g
Weight Loss: 14.1%
Rest: 8 days
Intent (originally): Not explicitly espresso-focused
Context
This morning wasn’t supposed to be significant.
It was simply an attempt to pull espresso from Roast 17 and see how it behaved under pressure.
What followed turned into one of the most important sensory calibration moments I’ve had since starting to roast at home.
Shot 1 — 20g in / 80g out / 30 seconds
The first shot ran at:
- 20g dose
- 80g yield
- 30 seconds
Structurally that is closer to a lungo than espresso (1:4 ratio).
The result:
- Light body
- Slight dryness after a sip or two
- Not acrid
- Not harsh
- Better with milk
At this point I had assumed the dryness might be roast-related.
It wasn’t.
Adjustment — 3 Clicks Finer
A small grind adjustment (3 clicks finer) produced:
- 20g in
- 42.2g out
- 30 seconds
Approximately a 1:2 ratio.
Everything changed.
Shot 2 — Structural Shift
The second shot was:
- Thicker
- Fuller in body
- No drying bitterness
- Noticeably more acidity
- Lingering aftertaste
Instead of dryness, I experienced:
Whole-mouth tingle
Acidity building toward a “wow” moment
Then softening
Not separate or lemon-like
Integrated into the cup
Most importantly:
The mouth was not drying.
This was the breakthrough.
The Eureka Moment — Sour vs Bitter
I’ve often struggled to differentiate sour and bitter in espresso.
This morning clarified it physically rather than intellectually.
Bitter (what I experienced in the first shot)
- Hits toward the back of the tongue
- Creates dryness
- Leaves a slightly chalky or hollow finish
- Often appears in longer extractions
The 1:4 shot dried the mouth.
That was bitterness from late extraction.
Sour (what I did not experience)
- Sharp spike at the front or sides of the tongue
- Immediate unpleasantness
- Thin body
- Makes you wince
The second shot was not sour.
It was acidic — but not sour.
Acidity (what I actually tasted)
- Whole-mouth tingle
- Integrated into body
- Builds, then softens
- Leaves a clean, slightly acidic coating
- Not drying
That distinction was huge.
Acidity can be intense without being sour.
Bitterness can be subtle without being acrid.
And dryness is a physical cue worth paying attention to.
What This Actually Taught Me
- The dryness in Shot 1 was extraction-related, not roast-related.
- Ratio matters more than I had been giving it credit for.
- A 3-click grind change can fundamentally alter perception.
- 14.1% WL Ethiopia under pressure leans lively and bright.
- My preference is becoming clearer.
The Personal Realisation
Years ago I had an espresso in Italy that felt:
- Warm
- Round
- Sweet-forward
- No sharp lingering acidity
- No drying finish
This shot was good — probably a 6/10 in resemblance — but it wasn’t that.
It was brighter.
More expressive.
More modern.
And while it was absolutely drinkable (excellent in cappuccino), it wasn’t the style I’m chasing.
That’s not failure.
That’s preference emerging.
Where This Leaves Me
Roast 17 at 14.1% WL:
- Extracts cleanly.
- Responds well to grind adjustment.
- Shows lively integrated acidity.
- Leans brighter than my preferred espresso profile.
The next experiment is obvious:
Push development slightly further (~15.5% WL) and observe structural change.
Why This Matters
This wasn’t about tasting notes.
There were no cherries, florals, or citrus descriptors involved.
It was about:
- Dry vs watering mouth
- Body vs thinness
- Integration vs separation
- Lingering acidity vs drying bitterness
This morning clarified something I’ve struggled with:
I can taste espresso.
I just needed the right framework.
Coffee. One roast at a time.