The previous consumption sequence roughly coincides with that of availability in the wine. Worth special note is the fact that urea was totally consumed. This is important because urea is known to be an unwanted compound for fermented drinks owing to its being a precursor for some carcinogens such as ethyl carbamate (Weber and Sharypov, 2009); however,although some urea formed during the wine ageing process, it was removed by the subsequent acetification process. l-serineand l-aspartic acid, which also formed during wine ageing, were completely removed by acetification.