The University of California at Davis 20 Point Scale System Organoleptic Evaluation Scoring Guide For Wine The Davis system was developed by Dr. Maynard A. Amerine, Professor of Enology at the University of California at Davis, and his staff in 1959 as a method of rating the large number of experimental wines that were being produced at the university.
The Davis system is quite straightforward. It assigns a certain number of points to each of ten categories which are then totaled to obtain the overall rating score for a given wine.
17 – 20 Wines of outstanding characteristics having no defects
13 – 16 Standard wines with neither oustanding character or defect
9 – 12 Wines of commercial acceptability with noticeable defects
5 – 8 Wines below commercial acceptability
1 – 5 Completely spoiled wines
Appearance (2 points) – The wine is given 2 points if it is brilliant, with no dullness, murkiness, or particles of sediment. If it is clear, but not flashing with light reflections, it rates 1 point. If full or cloudy it gets 0.
Color (2 points) – Acceptable colors for white wines are varying shades of yellow, gold, straw. Flaws are any amber tones, indicating oxidation. A rosé can be a true pink, or by reason of its grape source, tinged with deeper red or orange. Overly violet tints, brown tints of amber or deep red are faults. The color of red wines depends greatly upon the grape variety. Pinot Noir may be light enough to verge on transparency. Cabernet or Zinfandel will be deep red. Newer or younger wines will often have blue-purple edges, as older wines will show bronze edges.
Aroma and Bouquet (4 points). Aroma is the sensory impression arising from the mouth with the assistance of the sinus chimneys. Bouquet is fragrance detected by the nose. Either may be vinous, smelling like wine, but without any grape variety characteristics. The intensity may be light, medium, or high. Negative factors are odors that can be described as alcoholic, excessively woody, moldy or corked.
Volatile Acidity (2 points) – This is the term for Vinegary-ascensence. Does the wine smell of vinegar? If not, it rates 2 points. A slight vinegar smell will rate 1 point. If it smells of vinegar it rates 0.
Body (1 point) – This is the wine’s viscous nature identified as mouth-feel, also the binges, or alcoholic strength.
Astringency (2 points) – Tannins give a wine astringency (or bitterness), and so does the wood in which wine is aged. Younger wines will be rougher than older wines. The ideal is mellow softness, velvet, roundness. A young wine is not discounted for a natural tannin.
General Quality (2 points) – The only category for subjective appraisal, adjusting the score on the basis of the wine’s total performance.
For more information, see Amerine, et. al, Hilgardia, 28:536-539, 1959.