Artturi Ilmari Virtanen

Artturi Ilmari Virtanen was born on January 15, 1895, in Helsinki. Educated at the University of Helsinki and working in Stockholm with Hans von Euler-Chelpin, he served for decades as director of the Valio biochemical research laboratory.

Virtanen investigated bacterial fermentation in green fodder. In 1928, he developed the AIV method, adding measured hydrochloric and sulfuric acid to freshly harvested green silage to lower pH to approximately 4, halting enzymatic decomposition and harmful bacterial growth without destroying vital nutrients or vitamin A. His method allowed dairy cows to produce nutrient-rich milk throughout sub-Arctic winters, earning him the 1945 Nobel Prize in Chemistry. He later served as President of the Academy of Finland.