If you’ve ever taken a sip of stale beer then you know what an unpleasant experience it can be. Have you ever given any consideration as to why beer goes stale though? For the breweries behind your favorite beers, this is a primary concern. The know that when off-flavors like butter or cardboard creep in and impurities cause a hazy beer, even the most inexperienced beer drinker will know that the beer isn’t fresh.
To determine the shelf-life of beer, breweries run forced-aging tests to determine how typical storage impacts the flavor profile and turbidity (the haziness that’s primarily caused by proteins). In normal storage situations, flavor and turbidity are impacted by exposure to UV light and warm temperatures.
Instead of testing aging in real time, a common practice is to implement forced-aging tests. These involve heating the beer up to 40 – 60 °C for a set time and then reducing the temperature to 0 °C, at which time turbidity is measured. This warm and cold phases are repeated every 24 hours and a formula is used to calculate how this translates into real time. Approximately every day with a warm and cold phase translates into one month of normal storage time.
Herrenhausen, a private brewery in Hanover Germany had many options when it came to how they would implement these tests. At one point, a Memmert water bath was considered since forced-aging in water is also a common practice. However, after consulting with the Memmert team, they chose to use the Memmert Cooled Incubator ICP 110.
Heat transfer is slower in air than in water, however tests have shown that the duration of heat transfer isn’t a huge concern for beer forced-aging tests. The temperature differences are the most important aspect and the ICP incubators had added benefits like the display and documentation of temperature profiles, the ability to export log files from the device directly to a USB drive, as well as simple programming of individual forcing tests.
Additionally, there were safety and process benefits. Glass bottles would sometimes break in waterbaths due to the fast temperature transfer which would cause additional clean up. Also, since the bottles remained dry in the incubator they could be placed in the opacimeter directly without the added step of a wipe down.
To learn more about force-aging beer or Herrenhausen, read the full case study at AtmoSAFE. If you need advice on what Memmert appliance would be best for your needs, contact us!