Germany has long led the world in the production and classification of various styles of late harvest wines. Johannisberg Riesling and Gewürztraminer being the most commonly found varieties of late harvest designated wines. Generally, late harvest wines are the result of leaving ripe grapes on the vine for periods far in excess of their normal picking times. This results in an extreme concentration of sugars in the grapes. Many times late harvest grape clusters will be infected with botrytis cinerea mold, the famous “Noble Rot”, further concentrating the flavors and sugars.
In California, minimum standards for residual sugar at harvest have been set which are roughly in accord with the German standards (though it should be noted that California’s are higher than the roughly equivalent style). Chateau St. Jean, in Sonoma County, California, provides the following table of standards with its German equivalent:
- Early Harvest (Trocken/Halb-Trocken): Maximum sugar at harvest: 20.0 Brix
- No Designation (Kabinett): Minimum Sugar at harvest: 20.5 Brix, Residual Sugar: less than 2.6% by weight.
- Late Harvest (Spatlese/Auslese): Minimum sugar at harvest: 28.0 Brix, Residual sugar: less than 11.5% by weight, Some incidence of Botrytis
- Select Late Harvest (Auslese/Beerenauslese): Minimum sugar at harvest: 28.0 Brix, Residual sugar: usually over 11.5% by weight, Only grapes affected with Botrytis
- Special Select Late Harvest (Beerenauslese/Trockenbeerenauslese): Minimum sugar at harvest: 35.0 Brix, Residual sugar: usually over 15.0% by weight, Fruit totally affected with Botrytis, some berries fully raisined.