Corn steep liquor

Corn steep liquor is a by-product of corn wet-milling.^[1] A viscous concentrate of corn solubles which contains amino acids, vitamins and minerals,^[2] it is an important constituent of some growth media. It was used in the culturing of Penicillium during research into penicillin by American microbiologist Andrew J. Moyer.^[3] It is an excellent source of organic nitrogen.^[1]

A lab worker spraying penicillin mould into flasks of corn steep liquor, 1943

Corn steep liquor has CAS number 66071-94-1 and EC Number 266-113-4.^[2]