Off Flavors in Homebrewed Beer – Troubleshooting Off Flavors

This week I take a look at the 17 off flavors in home brewed beer found on the BJCP beer judging score sheet. These are the major off flavors you will encounter when home brewing beer, and I’ve also provided links to my more detailed summaries of the causes and correcting each flavor.

Off Flavors in Beer

For those of you unfamiliar with the Beer Judge Certification Program at BJCP.org, it is the worlds largest program for certifying beer judges who evaluate beers for most of the beer competitions here in the US. They also publish a style guide of standard beer styles along with a number of other references on judging and tasting beer. Even for those who are not into competing, their standards are a great reference.

Along with judging materials they also publish the BJCP score sheet which is a scoring sheet used by beer judges. I don’t compete with my beer, but I have used the score sheet on many occasions to evaluate my beers.

On the score sheet is a short summary of 17 off flavors found in beer, and it is a useful guide. While it won’t cover other problems like imbalances in your beer, it is very useful to know the off-flavors as well as how to troubleshoot them.

I’ve written articles on all of the major off flavors, so I’ve provided a link below to the major article on each off flavor so you can bookmark this page and use it if you are trying to troubleshoot an off flavor in your beer:

Acetaldehyde – A green-apple aroma and flavor that is associated with problems during fermentation.
Alcoholic – Excessive warmth, flavor and a hot finish caused by the presence of higher order alcohols.
Astringent – A puckering, harsh bitter flavor like sucking on a tea bag. Grainy and husky – caused by excessive tannins.
Diacetyl – A movie-popcorn buttery flavor, hints of butterscotch or toffee. Caused by fermentation issues in most cases.
DMS (Dimethyl Sulfide) – A sweet canned or cooked corn flavor. Usually caused by an insufficient boil.
Estery (Fruity) – Fruity flavors like pears, roses, raisins, and estery aromas. Caused by fermentation problems or yeast selection.
Grassy – Lawn mower, fresh cur grass or wet leaves aroma/flavor. Caused by hops, excessive dry hops or poor ingredients.
Light Struck (Skunky) – Aroma and flavor of the skunk. Caused by direct exposure of the beer to sunlight.
Metallic – Tin, copper, iron or blood like flavors. Usually caused by metal in the beer or poor choice of cleaning agents.
Musty – Stale, musty or moldy aromas and flavors. Can be caused by poor ingredients or an actual infection.
Oxidized – Stale, cardboard, winey, paper or sherry like flavors. Caused by exposing finished beer to oxygen.
Phenolic – Spicy, clove/pepper or smoky, plastic, band-aid or medicinal flavors. Caused by yeast, fermentation, mash or water problems.
Solvent – Acetone, lacquer, paint thinner, or moonshine flavors. Caused by out of control ester production.
Sour/Acidic – Sour off flavors. Tartness and aroma of sour beer, lactic acid or vinegar. Caused by bacterial infection.
Sulfur – Aroma of rotten eggs or burning matches. Often caused by yeast and will frequently fade with time.
Vegetal – Aroma of rotten, cooked or canned vegetables. Caused by moist or stale ingredients.
Yeasty – Bready, sulfury or yeast like aroma. Caused by beer being too young or not properly cleared.

As I mentioned this is a summary article – so if you are interested in learning more about any of the off flavors above and getting to root cause, just click on the links above.

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