Today in 2007, US Patent 7186428 B1 was issued, an invention of Nick J. Huige, Murthy Tata, Jeffrey F. Fehring, Michael C. Barney, David S. Ryder, and Alfonso Navarror, assigned to Miller Brewing Company, for their “Method of Oxygenating Yeast Slurry Using Hydrophobic Polymer Membranes.” Here’s the Abstract:

Disclosed is a an economical method of efficiently oxygenating yeast slurry without bubble formation. The method employs a membrane oxygenator comprising at least one hydrophobic, microporous membrane having a gas side and a liquid side. The yeast slurry flows over the liquid side of the membrane; oxygen is delivered to the gas side of the membrane and passes through the pores to the yeast slurry.