Wine Arcana

Grape

Blanc du Bois

Blanc du Bois is a white hybrid grape developed in Florida for conditions where Pierce's disease can make susceptible wine grapes difficult to sustain. Its role extends through the southeastern United States and into Texas, particularly the Gulf Coast. Floral, citrus and sometimes Muscat-like character can appear in wines ranging from dry whites to sparkling and fortified styles.

The important qualification is that tolerance of a bacterial disease does not remove fungal-disease problems. Blanc du Bois can survive a threat that defeats many other vines while still demanding considerable protection.

Florida origins

John A. Mortensen's release circular records a 1968 cross between Florida D6-148 and Cardinal. After selection and trials, the University of Florida released Blanc du Bois in 1987. Its name honours Emile DuBois, a French immigrant who grew grapes and made wine in Florida.1. Mortensen, Blanc Du Bois: A Florida Bunch Grape for White Wine, 1987 release circular.

This is a warm-region breeding story. It differs from the emphasis on deep-winter survival associated with grapes such as Frontenac, even though both belong under the broad hybrid heading.

What tolerance does and does not mean

University of Georgia guidance explains that the Pierce's disease bacterium can occur within Blanc du Bois without the decline expected in susceptible vines. It also records serious susceptibility to anthracnose and other fungal diseases. Tolerance is therefore a specific biological advantage, rather than a promise of healthy fruit without management.2. University of Georgia, “Blanc du Bois,” disease and pest account.

Texas A&M describes vigorous growth and the use of high-wire, divided canopies to accommodate it. Fruit set can vary, and tight bunches in heavy-set years increase rot concerns. Training and canopy management help organize growth, expose fruit and allow access for vineyard work.

The vine is often grown on its own roots, but alkaline soils can make rootstock choice useful. Grafting in that case addresses soil adaptation; it is not the source of the fruiting variety's Pierce's disease tolerance.

Wine and harvest

Blanc du Bois ripens over a relatively short season. Texas guidance warns that extending hang time can cause berries to fall from their clusters, so waiting for ever-higher sugar is not a cost-free choice. Its juice also browns readily through oxidation, although it can lighten during fermentation.

The variety's southern relevance includes Georgia as well as its Florida origin and Texas use. Georgia's extension account describes still, sparkling and Madeira-style fortified possibilities. The latter refers to a method and stylistic ambition; it does not make a Texas or Georgia wine Madeira. Across these uses, harvest condition and cellar decisions help determine how its aromatic fruit reaches the bottle.

Sources