4118 ASBC Mebership Graphic.jpgFriend or Foe: A tale of malting barley-free amino nitrogen content and impact on beer flavor​​​​​​

​Broadcast Date: August 30, 2018

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​Webinar Summary

Malt Free Amino Nitrogen (FAN) provides one of the main sources of nitrogen for yeast metabolism during wort fermentation. FAN comprises individual amino acids and small peptides (di and tri-peptides). Of the 20 essential amino acids wort contains 19 amino acids that yeast assimilate in preferential order at varying rates depending on yeast strain. Brewers look to FAN to determine yeast potential growth and fermentation efficiency; insufficient yeast nutrient leads to difficult fermentation and possible sulfur and other off flavor formation. Although healthy fermentations require adequate FAN, excessive FAN levels contribute to negative flavor attribute formation, lowering overall beer quality and hence flavor stability. Because yeast uptake of specific amino acids is ordered malt amino acid profiles also influence beer flavor potential and flavor stability.

In this study single malt beers were produced using North American production malt types. FAN was monitored in the malt and wort, during 14 days of fermentation and in the finished beer. Amino acid profiles were assessed for the wort and finished beers. Descriptive analysis by trained sensory panel and GC-MS profiling was used to evaluate differences in beer flavor and flavor stability after storage in order to better understand the relationship between FAN and beer flavor.

About the Presenter

Pattie Aron

Pattie Aron
Rahr Corporation

Pattie Aron obtained a B.S. in Biochemistry from Elmira College and both her M.S. and Ph.D. degrees in Food Science and Technology from Oregon State University. Pattie’s passion for fermentation led her to conduct graduate research in wine chemistry and brewing science. From 2011- 2016 Pattie was the Senior Hop Chemist in the Applied Brewing and Research team at MillerCoors. In this role she researched and innovated hopping products and technology, directed brewing trials related to hop variety development, and developed a hop sensory program. Her research also focused on off flavor troubleshooting as well as beer flavor and flavor stability pertaining to hops and other raw materials. In her current role, Pattie is a brewing and raw materials chemist for Rahr Malting. She currently conducts research and development on brewing, wine, and distilling raw materials and manages the technical research and brewing laboratories in the Brewing Research and Innovation group at the Shakopee, MN headquarters.