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118 WINES&VINES January 2016 WINEMAKING PRACTICAL WINERY & VINEYARD Fermaid O for organic nitrogen) and applied two nutrition strate- gies using the same amount of YAN: 16 mg/L, in organic com- pared to the inorganic form. A third fermentation was performed without nutrition, as a control. The graph "Impact of Inor- ganic and Organic Nutrition on Alcoholic Fermentation" shows that for an equivalent amount of assimilable nitrogen added, the addition of organic nitrogen ef- fectively enables the fermentation kinetics (green line) to complete fermentation. With the inorganic nitrogen source added (purple line), the fermentation is sluggish then stuck, as is the case with the control fermentation (blue line) with no nitrogen added. For an equivalent dosage of YAN, an or- ganic nitrogen source is much more efficient than an inorganic nitrogen source. In a highly nitrogen-deficient must (100 mg/L YAN), an appro- priate organic nutrition strategy is sufficient enough to complete alcoholic fermentation. Nitrogen impact on aromatic profile of wine The metabolism of nitrogen, no- tably from amino acids, generates the formation of numerous aroma IMPACT OF ORGANIC NUTRITION ON ALCOHOLIC FERMENTATION Impact of organic nutrition addition on alcoholic fermentation. 20 g/hl (8 mg/L of YAN) of organic nitrogen added at the beginning of the fermentation, and another 20 g/hl (8 mg/L of YAN) at one-third of the alcoholic fermentation. Fermentation rate (g/l.h -1 ) 0 50 100 150 200 250 300 350 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 20 g/hL @ beginning 20 g/hL @ 1/3 of the alcoholic fermentation (AF) Time (hours) Alcoholic fermentation without addition of nutrients Alcoholic fermentation with addition of organic nutrient (Fermaid O) ORGANIC NUTRIENT: ADDITION TIME COMPARISON Data comparing the two-step additions and a single addition at one-third of the alcoholic fermentation of organic nutrient Fermaid O. ORDER TODAY AND GET IMMEDIATE ONLINE ACCESS. The most current and comprehensive guide to wine and grape industry professionals, products and services in North America is now available online and in print. ORDER TODAY. winesandvines.com/order