"spirits distilled from other liquors" (especially wine), 1650s, abbreviation of brandy-wine (1620s) from Dutch brandewijn "burnt wine," earlier brand-wijn, so called because it is distilled (compare German cognate Branntwein and Czech palenka "brandy," from paliti "to burn"). The Brandywine Creek in Pennsylvania, site of the 1777 Revolutionary War battle, supposedly was so named 17c. by the Dutch explorers for the color of its waters.
In familiar use abbreviated as brandy as early as 1657; but the fuller form was retained in official use (customs tariffs, acts of parliament, etc.) down to the end of 17th c., being latterly, as the spelling shows, regarded as a compound of brandy + wine. [OED]