What are signs of Oxidation in beer?

Oxidation in beer often results in distinct off-flavors, with papery or cardboard-like flavors being a primary indicator. When beer undergoes oxidation, the chemical compounds in the beer react with oxygen, leading to the degradation of delicate flavors and aromas. This process can introduce stale or flat characteristics reminiscent of paper or cardboard.

On the other hand, fruity flavors can sometimes appear in certain beer styles, especially those with hop characteristics or yeast contributions, but they are not indicative of oxidation. Similarly, minty flavors are often associated with certain hop varieties or inappropriate storage conditions rather than the oxidation process. Bready flavors are typically a sign of malt presence and are not related to oxidation.

Thus, the presence of papery, cardboard flavors effectively signals that the beer has undergone undesirable oxidative reactions, making it a clear indicator of oxidation in beer.