n-Butanol and Acetone: Maize Mash Fermented by Weizmann's Bacteria

Weizmann's fermentation (US 1,315,585, 1919) turns maize starch into butyl alcohol and acetone. The bacteria live on the grain itself: you catch them by fermenting many small maize-mash cultures, keeping the ones that smell most strongly of butyl alcohol, and heating each subculture to 90–100 °C for a minute or two so that only their heat-proof spores survive. The finished culture ferments a sterilised mash of 100 parts maize meal in 1500 of water in about two days, and the mash is then distilled. The picture: our diagram.