Large group of volatile organic sulphur compounds (also alkanethiols, thioalcohols and, as an obsolete trivial term, mercaptans). They belong to the organic acids with a somewhat higher degree of acidity than, for example, alcohols and phenols. They are derivatives of hydrogen sulphide. They are formed during decomposition and rotting processes of organic material, for example during or after the fermentation of grape must from a chemical reaction with ethanol (drinking alcohol) or acetaldehyde. Among other things, this process is favoured by yeast sedimentation, which is common especially in white wines. Thiols are found as flavouring substances mainly in milk, cheese, onions and garlic.
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freier Autor und Weinberater (Fine, Vinum u.a.), Bad Krozingen