Louis Pasteur Publishes Studies on Beer

In 1876, Louis Pasteur published Études sur la bière, a major scientific study of beer fermentation, spoilage, and preservation. Pasteur showed how microorganisms other than brewer’s yeast could contaminate beer and cause sourness, undesirable flavors, and instability. He described microscopic methods for examining yeast and distinguishing healthy fermentation from microbial contamination. Pasteur also proposed practical measures for protecting beer, including cleaner handling, limiting exposure to airborne microorganisms, and using specially designed fermentation equipment. By applying microbiology directly to brewery problems, Études sur la bière helped move brewing quality control away from purely empirical observation and toward laboratory-based investigation. The book provided an important foundation for later brewery laboratories, pure yeast cultures, and more consistent industrial beer production.