Wine faults are unwanted and unpleasant characteristics of a wine that result from poor winemaking practices and/or storage conditions. The most common wine faults are reduction, oxidation, cork taint, cooked or maderized wine, lightstrike, volatile acidity, green aromas, brett or dried out (to old) wine. Note that many of the compounds that cause wine faults, for example sulfur compounds, volatile acids, but also Brett aromas are perceived as faults when they are present in the wine in high concentrations, but are pleasant in lower concentrations and add complexity to the wine. Further, the perception of a wine fault can be very subjective, depending on a person’s sensory threshold, but also on taste preferences. Therefore, whether volatile acids, brett aromas or green herbal aromas are too prominent can be a matter of debate. Nevertheless, wine faults like cork taint or lightstrike are beyond dispute (when noticed).