Today in 1919, US Patent 8409647 B2 was issued, an invention of Robert Harvey Moffett, Jeffrey Allen Odle, and Rafael Januario Calabrese, assigned to E. I. Du Pont De Nemours And Company, for their “Silica Microgels For Reducing Chill Haze.” Here’s the Abstract:
The present invention provides a method of reducing chill haze in a protein containing liquid (especially beverages resulting from fermentation such as beer and wine) by contacting the liquid with silica microgels having an average microgel diameter of at least 18 nm, more preferably at least 45 nm, and most preferably at least 70 nm. It has now been discovered that microgels having an average microgel diameter of less than about 18 nm do not adequately reduce chill haze of a protein containing liquid. In particular, while microgels having an average microgel diameter of less than about 18 nm cause the coagulation of haze-forming components, these components remain suspended in liquid and continue to cause haze despite allowing the liquid to settle for long periods of time. Conversely, it has now been discovered that microgels having an average microgel diameter of at least about 18 nm cause the coagulation and precipitation of haze-forming components and the rapid settling thereof without the use of an organic polymer which acts as a flocculating agent.