What are the key differences between blanc de blanc and brut sparkling wines?

Blanc de blanc sparkling wines are made exclusively from white grapes, typically Chardonnay, while brut sparkling wines can be made from a blend of white and red grapes. Blanc de blancs tend to be lighter and more delicate in flavor, with notes of citrus and green Apple, while brut wines are drier and more robust, with a broader range of flavors.