Do you teach your team to connect development time ratio to shot parameters? When I bring a light Ethiopia into the bar (end temp about 201°C, DTR 12–13% on a Probat P12), we start with a longer preinfusion and a tighter grind to push clarity without tipping into astringency, and I’d love to compare how you structure that lesson so baristas grasp the why behind the recipe.
With that 201°C, “12–13% DTR” Ethiopia on the P12, I run a three-shot ladder at fixed yield and temp — keep grind constant, then 6s/12s/18s preinfusion — and have trainees circle the first cup where astringency pops, then we go one notch finer and repeat so they feel the grind–preinfusion tradeoff. I’m with you on tighter grind, but on higher-flow pumps I cap preinfusion around 12s to avoid channeling; do you normalize to the same EY or just taste and pick?
I tie “12–13% DTR” to flow: cap peak about [redacted]/s, then fade pressure after 15s…
I have trainees bump brew temp +1°C on that “201°C” Ethiopia before touching grind, then taste it against a cooler shot to connect shorter development to solubility. If the machine doesn’t like the heat, I instead drop dose 0.5 g and hold yield constant to keep clarity without the drying edge. Do you log TDS to show the shift or keep it sensory?
I anchor the lesson on puck prep vs perceived “astringency”: run a bottomless with a paper under the basket and a puck screen, keep dose/ratio fixed, and have them taste how the paper cuts fines migration so a tighter grind gives clarity without bite — it’s a paper hat for the puck. Small caveat: if your water’s >50 ppm alkalinity, that same Ethiopia can read flat, so I drop HCO3– to about 30–40 ppm before tweaking preinfusion “so baristas grasp the why.” Do you ever teach it this way, @OP?