Today in 2008, US Patent WO 2008101298 A1 was issued, an invention of Allan K. Wallace, assigned to Coopers Brewery Limited, for his “Brewing Apparatus and Method.” Here’s the Abstract:

The specification discloses brewing apparatus and a method for testing for end of fermentation of a fermenting brew. It has been determined that, once fermentation is complete, the temperature of a brew (such as beer) shows a tendency to stratify in horizontal layers. However, the activity of fermentation disrupts the tendency of the brew to stratify. Accordingly, the brewing apparatus comprises at least two temperature sensors positioned to measure a temperature difference between the temperature at a first height of the brew and the temperature at a second height of the brew. End of fermentation is identified if the temperature difference is greater than a threshold difference.