The chemical nature of flavour in beer

Beer has been a popular beverage for thousands of years,and it is often described as the result of the oldest biotechnological process. The flavor of the beer comprises taste (not volatile compounds) and smell (volatile compounds). Beer constituents comprise more than 800 compounds and many of them contribute to its fl avor characteristics, such as bitterness, sweetness, acidity, hop character, carbonation, alcoholic and fruity or ester flavor. These flavor notes derive from volatile and not volatile chemical compound influence. Alcohols,esters, carbonylic compounds, phenols, terpenes, etc. are only some of chemical classes to which these compounds belong. These compounds influence beer fl avor when their level is higher than the threshold value. However, synergic effects of more compounds are able to take a determinate compound to underline a determinate fl avor (taste or odor) even without that the same is over its threshold value. Besides the compounds infl uencing positively the fl avor, there are others that,even though generally present in small concentrations, can give formation to off-flavor conditioning the general beer flavor. The importance of a particular compound as regards to its contribution to beer fl avor is determined by its concentration, odor and taste threshold values, and its interaction with other volatile and non-volatile constituents.