Source, in full
This is misattributed to Pasteur in multiple sources, usually used as evidence that he had recanted germ theory, but it also appears in scientific literature. The actual quote is of Claude Bernard, a contemporary of Pasteur who disagreed with germ theory, as quoted in "The Terrain Within: A Naturalistic Way to Think" (2012), and "Louis Pasteur, and the Myth of Pasteurization" (2013)