Fermaid K – Complete Yeast Nutrient for Strong, Clean Fermentations
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Provides a balanced blend of organic and inorganic nitrogen to support vigorous yeast growth
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Delivers consistent fermentation kinetics and helps prevent sluggish or stuck ferments
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Reduces the risk of off-aromas such as hydrogen sulfide by supporting healthy yeast metabolism
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Enhances fermentation security, especially in high-sugar musts or stressful conditions
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More immediately available YAN than Fermaid O due to its inclusion of diammonium phosphate (DAP)
Fermaid K is a widely used yeast nutrient developed by Lallemand to support strong, reliable alcoholic fermentations. It contains a combination of inactivated yeast (for organic nutrients) and diammonium phosphate (DAP) to supply both slow- and fast-release nitrogen. This dual-action profile provides yeast with the nutrients they need throughout the growth phase and active fermentation, improving cell viability, reducing fermentation stress, and minimizing the formation of undesirable sulfur compounds. Fermaid K is especially effective in fermentations that begin with low YAN, high sugar content, or other challenging conditions that demand immediate nitrogen availability.
Fermaid K contributes approximately 1 ppm of measurable YAN for every gram per hectoliter used. That means:
In comparison, Fermaid O contains only organic nitrogen and provides about 0.4 ppm measurable YAN per gram per hectoliter, or 40 ppm per gram per liter, and 151 ppm per gram per gallon. Fermaid O is preferred for slower, more controlled fermentations or when avoiding inorganic nitrogen is important. Fermaid K is ideal when rapid yeast growth and fermentation speed are critical.
Protocol
Rehydrate yeast first, then add Fermaid K at the end of the lag phase (typically around 24–48 hours after inoculation or at approximately 1/3 sugar depletion). Suspend in 10 times its weight of clean must or water, stir thoroughly, and add to the fermenting must with adequate mixing. Avoid adding at the same time as sulfites or enzymes.
Usage Rates
Recommended dosage: 20–40 grams per hectoliter
= 0.2–0.4 grams per liter
= 0.76–1.5 grams per gallon
Adjust dosage based on initial YAN content, fermentation conditions, and yeast strain requirements. Use higher rates in low-YAN musts or high Brix ferments to maintain healthy yeast activity throughout.
Comparing the Yeast Available Nitrogen contribution of Fermaid K vrs Fermaid O
If you add 1 gram per liter of Fermaid K, it contributes 100 ppm of YAN.
If you add 1 gram per gallon of Fermaid K, it contributes approximately 378 ppm of YAN.
If you add 1 gram per liter of Fermaid O, it contributes 40 ppm of YAN (Yeast Assimilable Nitrogen).
If you add 1 gram per gallon of Fermaid O, it contributes approximately 151 ppm of YAN.
