Which of the following characteristics does not describe the taste contribution of hops?

Sourness is not a taste contribution associated with hops. Hops are primarily known for imparting bitterness, which helps to balance the sweetness of malt in beer. The bitterness from hops comes from the compounds called alpha acids, which are released during the boiling process when hops are added to the wort.

In addition to bitterness, hops also contribute flavor and aroma to beer. The various hop varieties can impart a wide range of flavors, such as citrus, pine, floral, or herbal notes, enhancing the overall profile of the beer. Aroma is another key aspect, as certain hops are specifically bred to maximize their fragrant qualities, adding aromatic complexity to the final product.

Sourness, on the other hand, is primarily a characteristic of certain yeast strains or bacterial fermentation, contributing to the tartness found in styles like sour ales, but does not stem from hops. This distinction is crucial for understanding the role hops play in brewing and how they complement other ingredients in the beer-making process.