The most unfortunate thing for the chemists was the fact that Pasteur who was a chemist by training first established that “fermentation processes are result of microbial activity”. Actually a local brewery industry was facing a problem. Instead of alcohol, fermentation of sugar was producing lactic acid in their vats. They asked Pasteur to solve the problem. Pasteur found microscopically that instead of yeast the vat material contained some rod and spherical shaped small objects. He transferred the objects (vat infusion) into new sugar a solution, which results in further development of the same organisms in the solution & also lactic acids instead of alcohol, was produced. Further transformations in fresh sugar solution gave similar results. Pasteur thus named those small organisms “New Yeasts” that were actually bacteria and not yeast. But in Pasteur’s time microorganisms were not classified.