Before fermentation can begin it is important to know the status of nitrogen levels in the grape to see if supplementation is required for healthy ferments. Ammonia determination is one important component in the calculation of Yeast Available Nitrogen (YAN). YAN is described as the sum of ammonia ions plus primary amino nitrogen. If levels of YAN are too low this can result in sluggish or stuck fermentation compromising the quality of the product. Therefore, the most accurate determination of YAN all components should be qualified and this is possible using Randox Food Diagnostic Primary Amino Nitrogen (NOPA) kit.