4 Letter Word · Mexico Amatenango de la Frontera

Shot 1 on the Mexico Amatenango de la Frontera, pulled at 8 days post-roast — right at the producer's recommended 10-day minimum. Time came in at 24s (Fast) and ratio at 1.93 (Short), missing your Espresso target of 36.8g yield and a 25–30s window. You noted lingering sourness and attributed it to freshness, which is the right instinct here — but the spraying on the naked portafilter tells a fuller story worth addressing alongside the grind move.

24s is Fast by your labels. The ratio at 1.93 lands in Short territory, 1.2g under your 36.8g target. Balance 3 (slightly sour) with a linger is consistent with under-extraction, but 8 days on a medium-light washed bean that the roaster says needs at least 10 days means the freshness factor is real and compounding — CO2 outgassing disrupts extraction and pushes shots sour regardless of grind. The spraying on the naked PF in the first phase, combined with flow starting earlier on the right side, signals uneven distribution — a pattern you've seen before on right-side WDT undercoverage. The fast time and early right-side onset together suggest both grind and distribution are contributing.

Mexico Amatenango de la Frontera is a medium-light washed Chiapas from a cooperative, with toffee, caramel, and juicy orange notes — a profile that should read fruit-forward and clean when properly extracted. At 8 days post-roast, you're 2 days shy of the roaster's own rest recommendation, and CO2 outgassing on a fresh washed medium-light is a legitimate sourness amplifier right now. The lingering sour linger you're tasting is consistent with both under-extraction (fast shot, distribution issue) and under-resting — these are stacking. Closest comparable in your history is the Ándale Market bag 2, a medium-light washed Mexican/Guatemalan blend that dialed in at grind 28 — but that's a very different grind range given the bean density differences. More useful starting context: your 4 Letter Word Matas (medium-light washed Brazil) dialed in at 38.5, and bag 31 Shoondhisa (medium-light natural) is running at 42. A medium-light washed Chiapas at grind 40 running fast suggests 38 is a reasonable target zone.

Right-side early flow on the naked PF is a pattern you've now caught and corrected on multiple beans — you identified it here immediately. That's real diagnostic progress.