Czech wine of these festivals in Znojmo, Mikulov, Brno and Mělník will feature samples of hundreds of local wines as well as local music, dancing and cuisine. These wine-festivals take place in big towns apart from the wine-producing areas as well (such as Prague). Czech wine law classifies wine according to the origin of the grapes and the ripeness of the grapes determined by measuring the must weight in the grape juice at the time of harvest. Sugar content is expressed in units of °NM on the Czecho-Slovak Normalised Must-Weight Scale (Czech: "Normalizovaný moštoměr"), which indicates how many kilograms of sugar are
Phenolic content in wine the vanilla notes in wines that have been aged in oak. Trace amounts of vanillin are found naturally in grapes, but they are most prominent in the lignin structure of oak barrels. Newer barrels will impart more vanillin, with the concentration present decreasing with each subsequent usage. Oak barrel will add compounds such as vanillin and hydrolysable tannins (ellagitannins). The hydrolyzable tannins present in oak are derived from lignin structures in the wood. They help protect the wine from oxidation and reduction. 4-Ethylphenol and 4-ethylguaiacol are produced during ageing of red wine in oak barrels that are infected by brettanomyces