Analysis of Fermentation Gas from Home-Brewed Beer by Solid-Phase Microextraction (SPME) and GC/MS
Product: JMS-Q1500GC GC/MS System
Fermenters used for home beer brewing are fitted with an airlock consisting of a liquid barrier that permits the fermentation gases to escape while preventing contamination from atmospheric microbes. Large volumes of carbon dioxide are produced during the most vigorous stages of fermentation, which can occur as early as the first 24 hour period after an ale yeast is added (pitched) to the sweet liquid (wort) produced from barley during the initial mashing step. The gases emitted from the airlock can have a pleasant aroma that can be quite distinctive during the initial stages of fermentation. Solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS) was used to determine the volatile components contained in the fermentation gas.
Five gallons of beer were brewed using 11.5 pounds of 2-row malt and 1.5 pounds of debittered black malt. Homegrown Columbus, Chinook, and Centennial hops were added at different stages during the boil for bittering and aroma. Wyeast 1098 British Ale yeast was added to the cooled wort to initiate fermentation at a temperature of approximately 21.1°C (70°F).