Free amino nitrogen
In
fermentation.[1]
The exact components of FAN will vary from the composition of the
wort or grape must. In wine, all 21 amino acids can be found in trace amounts with arginine, proline and glutamine being the most abundant. However, as Saccharomyces cerevisiae, the primary yeast for both beer and wine, can not utilize proline in the anaerobic conditions of ethanol fermentation it is not included in FAN (and subsequently YAN) calculations.[1]
In winemaking
The amount of FAN that winemakers will see in their grape depends on a number of components including
vintages. The typical wine grape will have anywhere from 22 to 1242 mg of nitrogen/liter derived from free amino acids.[2]
In brewing
For vigorous
fusel alcohols, or spoilage of the finished beer
by other organisms.
References
- ^ ISBN 0387333495
- ^ Sara E. Spayd and Joy Andersen-Bagge "Free Amino Acid Composition of Grape Juice From 12 Vitis vinifera Cultivars in Washington" Am. J. Enol. Vitic 1996 vol. 47 no. 4 389-402
External links
- Research Newsletter[permanent dead link] of the International Centre for Brewing and Distilling, Winter 2003.
- Making Sense of FAN, Moritz Kallmeyer.