P-2
Nitrogen analysis in beer using a Zahm Custom Sample Bottle. Nitrogenated draft beer has been available for years and provides the
consumer with an alternative to traditional draft beers. Accurate analysis of
the nitrogen content in beer is needed to ensure the quality and consistency of
the product. While both in-line and portable nitrogen meters are available, they
are expensive. Furthermore, the use of a dedicated nitrogen analyzer adds
another instrument to be maintained and calibrated. The use of Orbisphere
packaged beer analyzers has become standard in many breweries for measurement of
Total Package Oxygen (TPO) and CO2. These instruments can also calculate
nitrogen based on headspace partial pressure. The use of a laboratory instrument
offers certain advantages in that they are more easily maintained and calibrated
than in-line instruments. However, the accurate measurement of nitrogen in beer
intended for draft dispense with a laboratory instrument requires the
presentation of a representative sample. This does present certain difficulties
due to in insolubility of nitrogen in beer and the requirement of a headspace
component in the sample. A solution to this problem was provided with the
development of a modified Zahm bottle, fitted with a piston release mechanism to
create package headspace. The newly developed nitrogen measurement procedure was
evaluated for reproducibility and was compared with the results obtained using
conventional analysis for non-CO2 gas.
Gregory Kreder received a B.S. in Chemistry from Southern Illinois
University in Edwardsville. He began employment with Anheuser-Busch in May 1989
as a chemist in the analytical laboratory of Brewing Technical Services. Since
January 1990, he has been conducting research in all facets of brewing,
including new product development in the Brewing Technical Services Pilot
Brewery. He has served the ASBC on the local level as secretary through Past
President (1996-2000).
Gregory C. Kreder. Brewing Technical Services, Anheuser-Busch Inc., #1 Busch
Place, St. Louis, Missouri 63118.