Today in 1999, US Patent WO 1999060090 A1 was issued, an invention of Mustafa Rehmanji, Andrew Mola, Robert Ianniello, Kolazi S. Narayanan, and Tom Cheng, assigned to Isp Investments Inc., for their “Premix Composition For Clarifying Beer.” Here’s the Abstract:

A premix composition for clarifying beverages like beer includes, by weight, (a) about 40 to 90 %, preferably 60-85 %, of silica xerogel having less than 10 % water therein, preferably 5 % or less, and a particle size, as defined by its mean volume average diameter MV, in both the dry state and as a 10 % aqueous slurry, of less than 50 ν, preferably about 5-30 ν, and (b) about 10 to 60 %, preferably 15-40 %, of crosslinked polyvinylpyrrolidone having a particle size as defined, in the dry state, of about 10 to 50 ν, and about 30-60 ν in a 10 % aqueous slurry, and a process of obtaining, chill-haze stabilized beer with substantial reduction in high molecular weight proteins, as well as polyphenols, flavanoids and tannins, in an efficient and effective single-step process at a rapid filter-flow rate, with undetectable residual soluble polyvinylpyrrolidone thereafter, and no microbiological growth in the premix, effective haze stability after time, and advantageous redispersibility of the premix used in the process.