The face of the reviewer is irrelevant; the integrity of the testing is everything.
THE PROTOCOL
Reviews are conducted on new, calibrated hardware and self-purchased unless specified. A provided unit is always a test subject and performance is measured, not influenced. Whether self-funded or provided for testing, the data remains indifferent to the source.
THE STANDARDS
The basis of all my reviews start with actually using the product as a daily driver. This not only helps understand the good and the bad from hands-on experiences, but gives ample time to identify patterns and consistencies in taste. I will never write a 'review' of a product without actually using and testing it first, unlike many major media publications.
Outside of personal opinion, data drives the rest. DiFluid Omni particle analyzer and R2 Extract TDS Refractometer helps identify the patterns and consistencies in grind settings and brews. Reviews are rounded out with sound decibel and retention tests.
UNDERSTANDING THE DATA
If the data referenced in my grinder reviews leaves you scratching your head, here's a quick rundown.
Between-Run SD (Standard Deviation)
Between-Run SD measures the absolute mechanical variance of your grinder. It tracks exactly how much the median particle size ($D50$) wanders from dose to dose when the dial is left completely untouched.
- What it tells you: If you grind five separate 15g doses, this number tells you the exact micron spread of those outcomes. A low SD means the burrs are locked in tight; a high SD means the burr carrier is shifting, wobbling, or feeding beans inconsistently.
Repeatability CV (Coefficient of Variation)
Repeatability CV measures the relative mechanical variance. It takes that absolute micron drift (the SD) and calculates how large that error is relative to the overall size of the coffee grounds.
- The Formula: (Between Run SD / Mean D50) x 100
- What it tells you: It translates absolute raw data into actual brewing impact. It answers the question: "Does this micron drift actually matter for this specific brew method?"
Looking only at Between-Run SD can be highly deceptive because a 30-micron error matters a lot more for espresso than it does for a French press. Repeatability CV solves this scaling issue.
THE OPERATOR
An end-game hobbyist and obsessive tinkerer with a love for espresso.
Barista Certifications: