Abstract
Fermented beverages such as beer are known for their relatively long shelf life. However, the main factor limiting their shelf life is the qualitative changes that occur during storage. From the moment the beer is produced, its characteristics, such as taste, aroma, and colloidal stability undergo continuous change. The intensity of these changes depends on the type of beer, storage conditions, and length of storage. While some degree of ageing can have a positive influence on sensory characteristics of a beer, beer stalling is seen as a significant problem. As it is currently understood, beer ageing is mainly caused by the formation of stalling aldehydes. At the same time, compounds which bestow the beer its flavour, such as esters, terpenes, and iso-α-acids undergo qualitative and quantitative changes. As a result, aroma discriminants such as freshness, fruitiness or florality are often lost over time. In their place, aromas described as ribes, cardboard, bread-like, honey-like or sherry-like appear. The article aims to present the changes in beer sensorial, physicochemical, and microbiological characteristics during storage and the factors that affect beer quality during ageing The article also describes the variables which according to the current literature, may alter the flavour stability of a beer.