Part of the Flavor and Sensory school. Class 4 of 6.
The capability: you can name a defect rather than only notice one.
Prerequisites: Modules 14, 15, 28, 30.
The practice
Acquire or create reference faults and taste each against a sound sample.
Oxidized vermouth against fresh — the highest-yield four seconds in the curriculum, and it has to be done once.
Old juice against fresh.
An over-extracted infusion against a correct one.
A corked wine and a heat-damaged one, if you can find them.
Diacetyl and oxidation in beer.
And a line-sourced sourness against a clean tap — via the bottle-versus-tap comparison, per Module 32.
The reference
The sound sample, always alongside. A fault tasted alone teaches almost nothing.
What you are building
Names for things you would otherwise only be able to call "off."
Because a defect with no name cannot be taught, tracked, or looked for — and a bartender who says "something is wrong with this" has not helped anyone.
And the harsh-versus-dull discrimination specifically: harsh means too much acid, dull means old juice, per Module 12 — two defects, two fixes, confused constantly.
Verification and boundary
Blind: identify five faults from a set of ten samples.
Boundary: faulted product is not served, and any deliberate creation must comply with the local health authority's requirements.