Ron Pattinson joins us to talk about his latest publication in the MBAA Technical Quarterly. Abstract: Through research in German-language technical publications, such as brewing textbooks and chemical journals, this paper has assembled considerable information about German sour beer styles. Much of this material has never been available in English before, and the author has personally translated them from German. This paper will discuss information on the brewing techniques employed in producing these mostly extinct beer styles and details such as the original gravity and alcohol content. This latter information mostly comes from 19th century German chemical journals, which often published chemical analyses of German beers. This material demonstrates how many sour styles there once were in Germany and how common they were in some parts of the country.