Crush and Squash

When the grapes are crushed the glycosides will enter the water phase of the must (read wine!), and it is tempting to speculate that some of the aglycons may be less soluble than their glycosylated equivalents. Nevertheless, due to the acid environment of the must and the presence of a rich microbiological fauna (bacteria and yeast) that contain glycoside-hydrolyzing enzymes, some, but not all glycosides will be cleaved and yield flavour-active aglycones. This relase of flavour may very well be responsible for the generation of the flavour that we recognize in wine, since the grape berries and freshly crushed berries seldom taste the same as the resultant wine. Another source for the transformation from a rather boring crushed berry flavour (crushed grapes often have little interesting flavour) to some of the marvellous characters associated with wines of differing origin and cultivars, may be attributed to the chemical and/or microbiologically induced chemical transformation of grape-derived potential flavour compounds. Thirdly, the presence of alcohol may also enhance the volatility of certain compounds.