Mikulovská wine grown in Mikulovská than any other Moravian region. The most planted red varieties are Saint Laurent ("Svatovavrinecké", 310 ha), Blaufränkisch ("Frankovka", 248 ha), Zweigelt ("Zweigeltrebe", 181 ha), and Pinot noir ("Rulandské modré", 172 ha). Plantings of Blauer Portugieser ("Modrý Portugal", 92 ha) has decreased rapidly, while Cabernet Sauvignon (89 ha) has increased. The Czech Wine Classification System, set in the Viticulture Act of 2004, is based on the sugar content of the grapes at harvest. Sugar content is measured using the Normalizovaný moštomer (°NM) scale, a measure of how many kilograms of sugar are in 100 litres of must. 1
Phenolic content in wine grapes varies depending on the variety with Cabernet Sauvignon, Nebbiolo, Syrah and Tannat being 4 of the most tannic grape varieties. The reaction of tannins and anthocyanins with the phenolic compound catechins creates another class of tannins known as pigmented tannins which influence the color of red wine. Commercial preparations of tannins, known as "enological tannins", made from oak wood, grape seed and skin, plant gall, chestnut, quebracho, gambier and myrobalan fruits, can be added at different stages of the wine production to improve color durability. The tannins derived from oak influence are known as "hydrolysable tannins" being created from