The amount of YAN that winemakers will see in their grape musts depends on a number of components including grape variety, rootstock, vineyard soils and viticultural practices (such as the use of fertilizers and canopy management) as well as the climate conditions of particular vintages.R. Jackson "Wine Science: Principles and Applications" Third Edition pgs 90-98, 151, 167, 183, 305-310, 356-357, 375-387, 500, 542 Academic Press 2008
