Louis Pasteur received a commission from a maker of beet root alcohol in 1856 while working at the University of Lille. The owner had grown tired of seeing entire batches of his product poured out before they could be sold. Pasteur dove into the research, carefully examining beet root juice at each stage of fermentation. As he observed the shift, he noticed a number of spherical organisms floating in the liquid — yeast, the microbe that consumes sugar to transform it into alcohol. Days later, as the juice soured and became unusable, Pasteur looked again and found something quite different: rod-shaped organisms — a bacteria. He came to the conclusion “germs” caused the change, a far-reaching discovery with implications in medicine.
With his research proved, Pasteur received an appointment from Emperor Napoleon III to apply his knowledge to French wine. Working in conjunction with his research assistant Bernard beginning on April 20, 1862, Pasteur came up with exact measurements for temperature and the amount of time necessary for preservation. The results were a revelation: wine could last much longer so long as it was not contaminated after being pasteurized. Within months, beer and vinegar were added to the list of materials subject to the process, literally saving vast portions of French agricultural products for export. Years later, Pasteur’s method would be turned to milk.
If there’s one food science breakthrough that stands apart from the rest, it’s pasteurization, milk pasteurization to be specific. Its very adoption changed the health of world. During the 1850s, fewer than half of all children born lived to see their 5th birthday, with tainted milk being the biggest cause of illness. Through separate approaches of low- and high-heat, pasteurization eliminated tuberculosis bacteria and drastically reduced the number of infections suffered during the early 20th century. Because of Pasteur and Bernard’s work, tens of thousands of life-threatening illnesses are avoided every year.