Final answer:
The first product to be commercially treated by pasteurization was wine, thanks to Louis Pasteur's discoveries in 1856. Milk pasteurization began in the 1860s to ensure a safer drinking product by eliminating harmful pathogens.
Step-by-step explanation:
The first product to be commercially treated by pasteurization was wine. Louis Pasteur discovered microbial fermentation in 1856 while studying the causes of spoilage in beer and wine, which eventually led to the development of the pasteurization process. Although cheese production and the fermentation of milk into yogurt have ancient histories, it was the study of beer and wine spoilage that directly led to the pasteurization technique. Pasteur's discoveries later sparked the pasteurization of milk in the 1860s, aiming to make it safe for consumption by heating it to eliminate pathogens.