Feed your fermentation with FermFed DAP Free by CellarScience™. The 100% natural formulation of FermFed DAP Free is derived from the autolysis of very specific yeast strains naturally high in free amino acids, sterols, mannoproteins, zinc, magnesium, and niacin, along with vitamins B1, B2, B5, B6, and B12 for a complete yeast health regimen. As the name suggests, this unique formulation does not contain the traditional inorganic diammonium phosphate, but does provide organically derived nitrogen.
How Much Do I Add and When?
The recommendation that covers most fermentations is to add 1.5 gram per gallon of FermFed DAP Free at the onset of fermentation and then add 1 gram per gallon of FermFed
after 1/3 sugar depletion. Mix the nutrients in a small slurry of water and add to the fermentation. Read more below if you are interested in measuring YAN (Yeast Available Nitrogen) and adjusting your nutrient schedule accordingly.
The Science of How it Works
The different components of FermFed DAP Free work in different ways to feed and protect your yeast.
The complex and organic nitrogen in FermFed DAP Free helps eliminate excessive yeast growth in the initial phases, reducing fermentation heat spikes at the start of fermentation.
Included sterols make the yeast membrane more resistant to alcohol and to high temperatures.
The collection of B-vitamins along with zinc and magnesium are essential for enzymatic activity, alcohol tolerance, and yeast health.
Mannoproteins help avoid the aromatic stripping during the fermentation by binding esters and terpenes and not allowing them to be driven off by CO2.
The included yeast hull components act as receptors to bind up fatty acids that can accumulate and cause stuck fermentations.
Advanced - Adjusting Your Nutrient Schedule Based on YAN (Yeast Available Nitrogen)
In addition to the nutrients provided by FermFed or FermFed DAP Free, yeast need a certain level of nitrogen to perform adequately. If deprived of nitrogen, yeast are more likely to produce off flavors, most notably hydrogen sulfide. When added at the rate of 1 gram per gallon, FermFed provides 38ppm of YAN while FermFed DAP Free adds 30ppm at the suggested usage of 1.5 grams per gallon.
How much YAN do you need? Acceptable levels range from 175 to 300ppm. YAN levels in grapes vary, with grapes from warmer climates often having less. The best practice is to measure your grapes using a commercial wine lab or the Vinmetrica YAN Test Kit
along with a Vinmetrica Meter. If you know your YAN the following is a good general guide:
175ppm or above = FermFed DAP Free @ onset + FermFed DAP Free @ 1/3 completion (adds 40ppm YAN)
150ppm or above = FermFed DAP Free @ onset + FermFed @ 1/3 completion (adds 58ppm YAN)
125ppm or above = FermFed @ onset + FermFed @ 1/3 completion (adds 72ppm YAN)
Below 125ppm = FermFed @ onset + FermFed @ 1/3 completion + extra DAP
For a full yeast nutritional plan, use FermStart
when rehydrating your yeast, use FermFed DAP Free at the onset of fermentation, and use FermFed
after 1/3 sugar depletion.