There are several commercial off-flavor kits on the market. The one recommended by the Brewers Association is a kit called The Enthusiast, made by a company called FlavorActiV. The kit contains eight different beer off-flavors and ingredients to provide tastings for a medium-sized club. The Brewers Association offers the kit for sale for $150 for American Homebrewers Association (AHA) members and $200 for non-members. The Beer Judge Certification Program (BJCP) also offers a discounted kit to its members for $50.
But, homebrewers are nothing if not cost-minded and innovative. Our club member did some research online and found some doctored beer recipes that use common homebrewer or low-cost ingredients (he said he did not spend more than $10). Below are the off-flavors that we tasted:
|Flavor||Taste/Aroma||Adulterant||Amount Added||How Created|
|Sour/Acidic||Lactic acid||Lactic acid||18 drops food grade 88% lactic acid in 24 oz of base beer||Created during or after fermentation by lactobacillus. In non-sour beers, likely a problem with sanitation.|
|Sour/Acidic||Acetic acid||White vinegar||13.5 tsp vinegar in 24 oz of base beer||Created during or after fermentation by acetobacter. In non-sour beers, likely a problem with sanitation.|
|Astringency||Dry like tea||Grape tannin||5 tsp of tannin solution (1/4 tsp grape tannin powder in 5 TBSP water) in 24 oz of base beer||Created by mash pH rising too high, which pulls tannins from the grain husks. This is usually due to over-sparging.|
|Phenolic||Bandaid plastic or medicinal flavors||Chloraseptic||Add drops of chloraseptic to 24 oz of base beer, until plastic smell is clearly present||Often created by high-chlorine content in brewing water or lack of rinsing of bleach, when used as a sanitizer. Can also be created by certain yeast strains at high fermentation temperatures.|
|Diacetyl||Buttery/butter scotch||Butter extract||18 to 20 drops of extract in 24 oz of base beer||Yeast byproduct during fermentation, the amount of which is determined by yeast strain. Can be a sign of incomplete or sluggish fermentation.|
|Estery||Fruity||Banana extract||24 drops of extract in 24 oz of base beer||Ester created by yeast during fermentation, the amount of which is determined by yeast strain.|
|Alcoholic||Hot alcohol, burning flavor||Cheap vodka||Add vodka to 24 oz of base beer until hot-alcohol is present||Fermenting higher-gravity worts at hotter temperatures can lead to hot alcohols.|
Perception and comprehension of beer off-flavors is critical to being able to correct problems in the brewing process. This is true both at the homebrewing scale and and the production brewery scale. Conducting an off-flavor demonstration is a great way to help brewers develop a common "vocabulary" of flavor flaws and it can be a lot of fun. I highly recommend the Lug Wrench readers give it a try.
Here are some additional beer off-flavor resources:
- BJCP Guidelines for Doctoring Beer
- Mesa Verde Mashers Doctored Beer Presentation
- BJCP Off-Flavor Flashcards
- Meilgaard Beer Flavor Wheel