Slovak wine following terms: Víno bez zemepisného označenia - "Wine without geographic indication" is replacing former category of Stolové víno - Table wine. Minimum level of sugar content is 13 °NM. Víno s chráneným zemepisným označením - "Wine with protected geographic indication" - produced from grapes registered in the List of registered varieties, grown, produced and bottled in one of the Slovak wine regions, maximum yield per hectare wasn't exceeded, minimum level of sugar content was 13 °NM and it fulfills the requirements of established product specification. It can be indicated with traditional term regionálne víno if the grapes reached 15 °NM,
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