Which of the following ingredients is commonly used in Witbier for flavoring?

Witbier, a Belgian-style wheat beer, is traditionally brewed with specific ingredients that contribute to its unique flavor profile. One of the hallmark characteristics of Witbier is the use of spices, particularly coriander and orange peel, which are added during the brewing process.

Coriander gives the beer a subtle spiciness with citrus notes, while the addition of orange peel enhances its fruity, refreshing aroma and flavor profile. These ingredients contribute to the beer's light, hazy appearance and slightly tart finish, which differentiates it from other beer styles.

Barley malt is primarily used in many beer styles, but in Witbier, the malt base often includes a significant amount of unmalted wheat, making barley not a defining flavoring ingredient for this style. Cascade hops, while popular in many American-style ales for their floral and citrus characteristics, are not a traditional ingredient in Witbier, which typically uses native Belgian hops that are more subdued in flavor and aroma. Chocolate malt is used to impart darker colors and roasted flavors, which are uncommon in the light and refreshing profile characteristic of Witbier.

Therefore, the combination of coriander and orange peel is quintessential for flavoring in Witbier, making this choice the correct answer.