NOPA
The NOPA value indicates the yeast-usable nitrogen content in the must from grapes harvested. It also allows conclusions to be drawn about the nitrogen supply of the vines . With low NOPA values there is a risk of fermentation stagnation and the occurrence of false tones such as UTA and Böckser . The nitrogen that can be used by yeast also influences the aroma . Based on the value, the nutrient supply and the yeast strain can be adjusted to the must at an early stage. The NOPA value can be determined, for example, using an FTIR analysis with the GrapeScan or WineScan from Foss.