Wine tasting, as a production control technique, depends upon converting into words the impression created by the reaction of the wine on the taster 's palate. In order that one wine, tasted by several individuals, be reported in the same way by each, it is necessary that all of the tasters use the same words for the separate palate impressions the wine creates. The terms used in sensory examination fall naturally under the four headings of appearance, color, taste and odor.
I. APPEARANCE: The appearance of a wine is judged upon whether or not the wine seems clear or contains sediment or suspended material of a colloidal or larger particle size.
Brilliant: wines free of any visible solids and having a sparkling clarity. Clear: wines free of any visible solids but lacking the sparkling clarity of brilliant wines. Dull: wines having an easily seen, distinct colloidal haze, but are free of visible suspended material. Cloudy: wines containing large amounts of colloidal material or of suspended particles. Precipitated: wines containing non-colloidal material of crystalline or amorphous nature which may settle out as a visible deposit leaving the wine relatively clear.
II. COLOR: Wines obtain their color from the presence of flavonoid compounds that are present in the skins and flesh of the grapes.
A. White Wines: contain several flavonoids which have been definitely identified. The interaction of oxygen with these substances, especially in the presence of trace amounts of metallic ions produces materials having amber or brown colors. Terms used in describing the colors of white wine follows.
1. Almost colorless or very light straw 2. Light yellow or light straw with or without a greenish tint 3. Medium yellow 4. Light gold 5. Medium gold
B. Amber Wines: Wines containing varying amounts of brown color