Dried Bitter Orange Peel is a dried spice often added to Belgian Witbier along with coriander. The fruit flavor also combines well with coffee, chocolate or roasty flavors in Porters and Stouts. Homebrew shops typically carry sweet and bitter orange peel varieties. The sweet peel will give a flavor similar to Grand Marnier, while the bitter version is more of a dry orange flavor. Heat will give the best flavor extraction.