The article describes the history of development of siliceous sols and gels used for hopped wort clarification and for improving of beer colloidal stability. The role of Dr. Raible is mentioned in the article. who used siliceous gels as the first person for increasing beer colloidal stability and his method was patented in Germany and all around the world by company Stabifix Brauerei ... https://www.ealisboa.com/great-deal-Pentair-Union-Collar-2-U11-200PS-super-offer/