contaminants, potentially harmful substances found in wine, either as a result of air or water pollution, (see smoke taint, for example), vineyard treatment residues, poor winery hygiene, contaminated pallets, packaging materials, or transport containers, ignorance, or adulteration and fraud. They are often difficult to identify and very potent, with extremely low perception threshholds, although the ability to detect them is not universal, even among professional tasters. A contaminant becomes a taint only once it can be smelt or tasted.
