Oxidised beer is often described as having a stale, winy, vinous, cardboard-like, or sherry-like aroma and flavour. This can be experienced in different ways depending on the type of beer and the level of oxidation. For example, in a New England IPA (NEIPA), oxidation can turn the beer’s vibrant, fresh-squeezed orange juice-like appearance into a brown, sludgy mess, and taste like blended cardboard.

Some beer styles, such as Old Ales and Barley wines, can benefit from ageing and develop flavours such as vinous and warming sherry.

Most people don’t enjoy the taste of cardboard or paper, and prefer to avoid oxidised beer. Even commercial brewers, who have sophisticated equipment, struggle to prevent oxidation in their beers. Homebrewers can also experience oxidation due to oxygen exposure during brewing and transferring processes. To avoid oxidation, it is important to minimize splashing and avoid any bulk movement of beer when transferring it from one vessel to another.

The BJCP describes oxidisation in beer as:

• Any of a combination of stale, winy/vinous, cardboard, papery, or sherry-like aromas and flavours.

Not everyone is sensitive to the popular descriptors of papery/wet cardboard in beer. It can sometimes be confused with the hop burn you experience with highly hopped beers.