Cabernet blanc is a hybrid crossing of the Vitis vinifera wine grape Cabernet Sauvignon and an unknown disease-resistant variety that is known under the catch-all name in Germany as Resistenzpartner. Masters of WineJancis Robinson, Julia Harding and Swiss geneticist José Vouillamoz speculate that the identity of Resistenzpartner may be a complex hybrid that is a crossing of Silvaner with another grape that itself is a complex crossing with a Riesling x unknown Vitis vinifera and JS 12417 x Chancellor parentage. This hypothesis is supported by fact, that Cabernet blanc contain resistance markers Rpv3 and Ren3.
Viticulture
Cabernet blanc tends to produce loose clusters of small, thick-skinned grape berries. The vine is a very vigorous, highly disease and frost resistant variety. It has particularly strong resistance to fungal infections caused by powdery and downy mildew as well as botrytis bunch rot. It is, however, susceptible to the viticultural hazard of millerandage where the grape flowers do not get properly fertilized resulting in bunches having a mix of small, seedless berries and normal size berries. These small "shot berries" often add to the levels of sugar and phenolic extract of the wine and may make it seem "unbalanced".
Wine regions
While Cabernet blanc was discovered in Switzerland and there are still limited plantings of the variety in that country, it is most widely planted in the German wine region of Palatinate in western Germany where there were of the grape in cultivation in 2007. Here the thick skin and high disease resistance of the variety lends itself well to the production of both dry and sweet late-harvest wines. Growers in Germany have submitted a request to put Cabernet blanc on the official list of registered grape varieties and, pending approval, plantings of the grape may increase in the country. Outside of Germany, Cabernet blanc is also found in the Netherlands were producers in Achterhoek and Gelderland are experimenting with the variety. Limited plantings of the grape also exist in Austria. While there are American wines being marketed as "Cabernet blanc" or "White Cabernet", these wines are sweet pink-colored blush wines made from Cabernet Sauvignon rather than from true Cabernet blanc.
Australian Cabernet blanc
In Australia, a golden-berried color mutation of Cabernet Sauvignon was discovered in a vineyard in the Langhorne Creek region of South Australia. This mutant, similar to the color mutation of Pinot noir that yielded Pinot blanc, was named Shalistin and propagated by Cleggett Wines to produce light-red wine. The vine eventually mutated again to produce "whiter" berries that was used to produce a completely white wine that Cleggett marketed as "Cabernet blanc" with the first vintage released in 2002. This white wine was described as having the berry fruit flavors of a red Cabernet Sauvignon wine with earthy, tannic notes. In 1989, a white-berried seedling of Cabernet Sauvignon, named Cygne blanc, was discovered growing in a garden in Western Australia that was planted next to a Cabernet Sauvignon vineyard. Unlike Cabernet blanc and Shalistin, Cygne blanc is neither a crossing nor a white color mutation derived from a cutting but rather a selfling that sprang from a seed of a Cabernet Sauvignon berry that fell on the ground and took root.
Styles
According to Master of Wine Jancis Robinson, Cabernet blanc produces white wine that have a flavor profile "somewhere between Riesling and Sauvignon blanc" with many of the aromas similar to Sauvignon blanc.
