Today in 2007, US Patent 7258887 B2 was issued, an invention of Patrick L. Ting, Henry Goldstein, Aki A. Murakami, Michael VanSanford, Jay R. Refling, John R. Seabrooks, and David S. Ryder, assigned to Miller Brewing Company, for their “Preparation of Light Stable Hops.” Here’s the Abstract:
Disclosed are methods for the production of light stable hops, useful for the brewing of beer or ale to be stored in clear or green glass containers, which beer or ale will not develop objectionable flavor as a result of exposure to light. Light stable hops are prepared by double extraction of liquid/supercritical CO2 extracted hop solids with ethanol to remove alpha/iso-alpha-acids. Such alpha/iso-alpha-acids may be further removed from the ethanol extraction liquor obtained in the double extraction process by subjecting such liquor to an ion exchange medium, or precipitation by a metal ion, heavy metal ion, or alkali metal ion, to provide an alpha/iso-alpha-acid is free extraction liquor which may be added to the light stable hops residue obtained in the initial double extraction process.
Wanting to continue using their distinctive clear bottle for Miller High Life, at least since 1962, Miller started coming with preparations to make certain hops less subject to becoming lightstruck. In 1962, they patented a Anactinic malt product and hop extract therefor and since then at least eight newer patents improves aspects of the same idea.