Nitrogen levels in grape must that are either too high or too low can cause sensory and economic issues in the production of fine wine. The amount of available nitrogen during fermentation is key to the healthy formation and reproduction of yeast, and completion of the process to dryness. The major yeast strain that dominates healthy alcoholic fermentation, Saccharomyces cerevisiae, typically produces one molecule of urea, glutamate, and proline from the metabolism of the amino arginine.