Metric Coffee · Colombia Carlos Efrain Cortes

Sat, Jul 18, 2026, 9:02 PM (Shot 82)

DoppioVery FastNormalDay 12 · Too fresh — wait (2d)

Shot

Grind Setting27.5

Dose18g

Grinder Retention0.1g

Adjusted dose 17.9g

WDT UsedYes

Distribution ToolYes

Spring Weight30 lbs

Pre-infusion6s

FlowNormal

Shot Time19s

Stopped at28.6g (+10g drip)

Yield38.6g

Ratio 1:2.162.03 g/sVery FastNormal

Target

Espresso

Aiming for Espresso (35.8g, 25–30s) — yield on target, ran fast.

Taste

Balance

SourSourBitter

Shot Rating

★★★★★

Notes

Flow started at around 9 seconds even across spouts but the shot ran fast. Taste is sour and lingering, curious why we went faster with a finer grind, maybe channeling that was not evident with the spouts flow or just the bean that needs to degas a few more days to be more stable and constant

Drink

DrinkFlat White

Milkwhole

Milk Quantity80ml

Foam10ml

Hot Water0ml

Overall Rating

★★★★★

Latte Art

Pollock

Big blob and spilled everywhere. Taste reminds me of berries, which is aligned to the flavor profile. A few sharp notes

Analysis

✦

AI Analysis

Needs Work

Summary

Grind 27.5 ran faster than grind 29 — 19s Very Fast vs. 24s — and tasted more sour with lingering acidity. Going finer made things worse, which is the diagnostic signal here: classic channeling behavior. Even, symmetric spout flow doesn't rule it out; a narrow channel can run fast and still look clean from the outside. The bean at 12 days on a light washed roast is also still slightly pre-peak, which adds real extraction resistance on top of any prep issue.

What the Numbers Say

Time hit 19s Very Fast — outside the Normal floor by 6 seconds despite the finer grind. Ratio at 2.16 is Normal, so yield was fine. Balance dropped to 2 (Sour) and quality to 2 stars. The counterintuitive result — finer grind, faster shot, worse taste — almost always points to channeling: the water found a path and ignored the rest of the puck. Lag was 10g, which is at the upper end of normal for the Bambino but not a flag on its own.

The One Thing to Change

Hold grind 27.5. Before the next shot, slow your WDT down and pay deliberate attention to right-side edge coverage — full depth, consistent pace, 25–30 seconds. Do not change grind until you've confirmed one shot with clean prep at this setting.

Finer grind producing a faster shot is the channeling signature. The grind isn't wrong — the puck prep may be the variable that broke down. Your known pattern is right-side WDT coverage as the active channel mechanism. Rule that out before moving the grind again. Additionally, at 12 days this bean is just shy of its estimated peak window (light washed ~14 days) — one more day of rest may also help puck stability.

Bean Context

Limoncello and blackberry are high-acidity notes, so some brightness is expected — but lingering sourness at this extraction speed is real under-extraction, not bean character. At 12 days, a light washed bean from 2015m is likely still slightly too fresh; the peak window starts around day 14 for this profile. Two more days of rest could meaningfully reduce resistance and make the grind behave more predictably. The bean isn't doing anything wrong — it just isn't ready yet.

Progress

Four shots in and you've correctly identified that this bean requires dramatically finer grind than anything previous — that's the right read. The finer-runs-faster result today is a useful data point, not a setback: it shifts the focus from grind to prep and freshness, which narrows the path forward.

Cached · Jul 18

Bean

RoasterMetric Coffee

BeanColombia Carlos Efrain Cortes

Days Since Roast12 days — Too fresh — wait (2d)

Roast Date2026-07-06