By German law, at least 50% of the grist must be malted wheat, although some versions use up to 70%; the remainder is usually Munich and/or Vienna malt. A traditional decoction mash gives the appropriate body without cloying sweetness. Weizen ale yeasts produce the typical spicy and fruity character, although extreme fermentation temperatures can affect the balance and produce off-flavors. A small amount of noble hops are used only for bitterness.