Louis Pasture proved multiple things with his research. He gave conclusive evidence against spontaneous generation as well as discovering fermentation and pasteurisation. He showed that fermentation occurred due to bacteria and microorganisms that grew in the substance. By proving that yeast was responsible for these bacteria, he began his case against spontaneous generation. Louis also discovered that heating beverages like wine, beer and milk to a certain temperature would kill off the bacteria inside, a method he called pasteurisation. To further prove that spontaneous generation was false, he conducted an experiment where he boiled broth in a swan neck flask. The flask is designed so that no dust particles could go in, only air. He found that unless the flask was broken, there was no growth of bacteria in the broth, concluding that it is particles in the air making it spoil not the air itself. This fact would later be used as a major groundwork for the germ theory of disease.