Fermaid® O is certified organic by OMRI. It is an autolyzed yeast nutrient with a high content of organic nitrogen (amino acids). It is formulated without DAP. It is best to add Fermaid O in two doses. Add half the dose at the end of lag phase (at the onset of fermentation) and the other half between 1/4 and 1/3 sugar depletion.
When calculating the YAN (yeast assimilable nitrogen) contribution from Fermaid O, use the following to guide your additions:
50 ppm nitrogen = 0.3 grams Fermaid O per liter 1/3 through the fermentation
100 ppm nitrogen = 0.2 grams Fermaid O per liter at onset of fermenation, then 1/3 through fermentatin add 0.2 grams Fermaid O per liter PLUS 0.125 grams Fermaid K per liter.
Notes about the YAN contribution of Fermaid O:
While a 1 gram per gallon (0.25 gram per liter) addition of Fermaid O will provide about 10 ppm of nitrogen, the nitrogen is more efficiently assimilated by the yeast than other inorganic sources of nitrogen such as D.A.P. You can expect about 3X three times the utilization of nitrogen. Therefore, a 10 ppm addition of nitrogen from Fermaid O may have a similar result to a 30 ppm addition of D.A.P.