Jeffrey Cohen (1); (1) Stone Brewing, Escondido, CA, U.S.A.
Analytical
Poster
Free Amino nitrogen (FAN) has been studied in beer for over 40 years
as it is an essential nutrient for yeast during fermentations; however,
the majority of the available reference material is based on lagers and
other traditional beer styles. Innovation from the craft brewing
industry creates an opportunity to expand this testing to encompass
other styles that are now widely present in the domestic beer market.
Using the internationally recognized ninhydrin method (ASBC Wort-12A),
seven craft beer styles, including two IPAs, two double IPAs, a session
IPA, a hoppy pale ale and an American strong ale, were tested. During
this ongoing study, wort and corresponding chilled pre-filtered beer
samples are collected during the fermentation processes; their
respective FAN levels are trended and have been used to help establish
baseline averages for each respective brand. On average, the IPA samples
tested to date have FAN levels of approximately 250 mg/L in the wort
and 133 mg/L in the pre-filtered samples. In contrast, the higher
gravity double IPAs have higher wort and pre-filtered FAN levels, 316
mg/L and 175 mg/L, respectively, which is expected due to the additional
malt used. It is known that FAN is a viable tool to monitor
fermentations and evaluate yeast health, so the purpose of this
experiment is to leverage it as a primary metric to track significant
process changes made between batches. Test data collected while tracking
a significant double IPA process change correlates with much more
efficient fermentations, which further demonstrates that monitoring FAN
levels in American craft ales, can be considered a critical control
point for supporting business decisions.
Jeffrey Cohen attended the University of California, Davis, from
September 2010 until June 2014, when he graduated with honors, receiving
a B.S. degree in food science and technology, with an emphasis on
brewing science. He began working at Stone Brewing. in July 2014 as a
quality assurance assistant in the analytical, microbiological and
sensory labs. Jeffrey is currently working as a quality assurance
technician, with a primary focus on the analytical chemistry of beer and
the brewing process. Jeffrey has recently been focusing on free amino
nitrogen testing, gluten analysis and packaged beer quality at Stone. He
plans on furthering his research on FAN and hopes to expand his
research to other aspects of brewing quality.
