BJCP Beer Evaluation Framework

1. Evaluating against a personal ideal rather than the BJCP style guidelines — marking down a hefeweizen for haziness, or an IPA for bitterness, when both are style-correct. 2. Failing to identify diacetyl at low concentrations — diacetyl threshold is approximately 0.1 mg/L; trained evaluators must detect it at this level, which requires repeated calibration tasting. 3. Confusing light-strike (skunking) with oxidation — both produce off-putting aromas, but skunking (mercaptan) is distinctly skunk-like, while oxidation is cardboard/wet paper. Treatment differs. 4. Missing fermentation character in Belgian ales — the phenolic and ester complexity of Belgian yeast is often confused with hop character or oxidation by evaluators unfamiliar with the style. 5. Assessing head retention as a quality metric universally — low head retention is a fault in Pilsner; it is acceptable in some high-alcohol imperial stouts. Context matters. 6. Conflating bitterness with astringency — bitterness (IBU, clean) is from iso-alpha acids from hops; astringency (rough, drying, tannin) is from polyphenol extraction from grain husks or excessive dry-hopping. They are different sensory experiences. 7. Scoring too low for style-appropriate characteristics — evaluators sometimes dock points for strong roast in a stout or high carbonation in a Berliner Weisse, both of which are required style elements. 8. Ignoring temperature when evaluating — serving temperature dramatically affects apparent bitterness, carbonation, and aroma intensity. All evaluation should note whether temperature was appropriate for the style.