Common Infection Organisms
Here are a few organisms that can infect beer, and their tell-tale characteristics that become present in beer.
Acetic Acid bacteria
Lactic acid bacteria
Fusarium (Barley mold)
Smells like vinegar
Smells like vomit
Cooked vegetable smell
Sour, smells like celery
Sour, buttery, or sometimes butterscotch taste, DMS (dimethyl sulfide)
Ropiness or oiliness on surface, beer remains cloudy once fermentation is complete, medicinal smell, harsh/unpleasant bitterness
This is mold that can contaminate barley in the field. Caused by excessively wet conditions will survive malting, kilning, and find its way into finished beer. Will cause uncontrolable gushing of bottles.