Trends in the composition of Australian wine 1984-2014

Abstract

Data for wines from the 2004-2014 vintages were collated from the database of analytical results of The Australian Wine Research Institute's Commercial Services Group and are reviewed in the context of historical trends in wine composition. Data for those 11 vintages were generated from 24066 commercially bottled Australian table wines (8384 white and rosé wines, and 15682 red wines), which were submitted to The Australian Wine Research Institute for analysis required to comply with the export/import requirements of destination countries. The wines include multiple vintages of a broad cross-section of Australian wines from commodity to icon status, and producers of all sizes. The wines represent a broad geographical and cultivar spread, with the proportion of wines of each cultivar strongly correlating with the planted vineyard area. The data relate to the compositional variables: alcohol, glucose plus fructose, total dry extract excluding alcohol, sugar and volatile acidity (TDE), titratable acidity at pH 8.2, pH, free sulfur dioxide (SO2), total SO2, bound SO2, and the ratio of free to total SO2. Certain previously identified year-on-year trends have continued, and in some cases appear to have accelerated in the most recent vintages, particularly with increasing glucose plus fructose concentration and pH in red wines. In other cases, previously identified trends appear to have gone into reverse, notably the rise in alcohol concentration in red wines, and for a period, rising TDE in red wines, and one new trend in red wines is apparent, namely decreasing titrable acidity. There is some indication that new trends are also apparent with white and rosé wines, namely decreasing alcohol, increasing glucose plus fructose, increasing pH and an apparent downward shift in TDE, although ANOVA indicates little statistical significance in those trends. Data related to the concentration of SO2 demonstrate upward trends in free SO2 for white and rosé, and red wines. This has occurred with a concurrent decrease in the concentration of total SO2 in red wines for the most recent vintages, leading to a consequent rise in the ratio of free to total SO2. A rise in the ratio of free to total SO2 is also seen in white and rosé wines due to increasing free SO2 concentration. Overall white and rosé wines display fewer upward or downward trends compared with that of red wines, but greater year-on-year variability in the data.