January 8, 2026
Grounds for debate
Systematically Improving Espresso: Mathematical Modeling and Experiment (2020)
Scientists blame your grinder; coffee nerds say “we knew”
TLDR: A study says grinder settings and water pressure drive espresso consistency and could cut bean use by 25%. Commenters split between “we already knew channeling,” demands for calibration details, and waiting for YouTube gurus to weigh in—proving coffee science isn’t official until the internet agrees.
A 2020 study tried to tame espresso chaos with math, claiming the real culprits aren’t your clumsy tamp but the grinder and water pressure—and promising protocols that use up to 25% fewer beans. The crowd? Split between “duh, it’s channeling” and “show me the calibration receipts.” One hobbyist cheers, “they’ve modeled espresso channeling,” while explaining the basics: when water finds tunnels in the coffee bed, extraction gets patchy and your shot tastes moody. The paper predicts yield drops when you grind coarser, but finds a peak in the middle—too fine or too coarse both flop—fueling the theory that inhomogeneous flow (uneven water paths) ruins consistency at fine settings. Engineers perked up: “parameterization, please,” imagining machine designers tweaking pressure like F1 pit crews. Meanwhile, the entertainment faction refuses to move until the YouTube High Council weighs in—“I’ll wait for the Lance Hedrick / James Hoffmann video”—and one commenter dropped a bibliography bomb so heavy it could be used as a tamp. The spiciest pushback: a methods critique about missing calibration for the espresso machine, raising eyebrows about reproducibility. Verdict: math meets crema, but the comments want proof, plots, and a Hoffmann monologue before crowning any new espresso gospel.
Key Points
- •A mathematical model and experiments identify grinder settings and water pressure as key drivers of espresso reproducibility.
- •Assuming homogeneous flow, the model predicts extraction yield decreases monotonically with coarser grinds.
- •Experiments reveal a peak in extraction yield at intermediate grind sizes, with lower yields at very coarse and very fine settings.
- •Findings indicate inhomogeneous flow at fine grinds contributes to poor reproducibility and material waste.
- •Proposed brewing protocols aim to reduce variation and cut coffee usage per shot by up to 25%, with potential economic and sustainability benefits.