Vitamin C was the first vitamin to be artificially synthesized in 1935. A process invented by Dr. Tadeusz Reichstein, of the Swiss Institute of Technology in Zurich. The Reichstein process uses a single pre-fermentation followed by a purely chemical route. The modern two-step fermentation process, originally developed in China in the 1960s, uses additional fermentation to replace part of the later chemical stages. Both processes yield approximately 60% vitamin C from the glucose feed.