Yeast Assimilable Nitrogen (YAN) is used to assess the nutritional status of juice, and can assist in planning appropriate additions of nutrients to minimise the possibility of a stuck ferment. A successful fermentation requires 100 – 200 mg/L of YAN. Insufficient or too high levels of YAN may cause stress to yeast, affecting fermentation kinetics and leading to the production of off-flavours such as hydrogen sulfide (H2S). YAN is the sum of Amino Acid Nitrogen (AAN) and Ammonia Nitrogen (AN).
Note: juice samples should be dosed with sulfur dioxide and frozen prior to despatch to prevent fermentation.
10 mL of sample required