Cheers, Louis.

Recently, whilst scouring the fermentation section of the science library, I stumbled across a thin, pamphlet style book, on the cover of which was a stamp; "Inaugural Professorial Lecture - University of Otago, 1996".
Upon closer inspection I noticed the name of the professor giving this special lecture. If you've already guessed it, kudos.

The professor was Jean-Pierre Dufour (or, 'JP'), who was appointed Professor, Chair of Food Science, at the university in 1995. JP continued his scientific research in the department up until his death in 2007, whilst attending an Institute of Brewing and Distillery conference in Nigeria. JP had a studded career and made great contributions to the fields of chemistry, microbiology, enzymology and food science. He also assisted in the success of Emerson's brewery in Dunedin, and so their annual Belgian-style release is entitled 'JP' in his memory.
For more information on these beers, see David Wood's article on JP 2009.

Needless to say, I had found a copy of the handout that would have accompanied JP's lecture - "Thank You Louis Pasteur: 120 Years of Brewing Science", was the title.
JP decided to pay homage to Louis Pasteur, a famous scientist who, like himself, had an impressive career in several fields of science and their applications.

I have come across Pasteur's name many times during my studies (you have too, every time you look at the milk carton, or if you buy beer that has been Pasteurised), but I have always neglected to educate myself on his overwhelming amount of contributions to the understandings of chemistry, fermentation, microbiology, medicine and disease.

Pasteur lived from 1822 to 1895, making massive developments in the field of fermentation and brewing, which led to greater studies of microorganisms and disease. Although Louis seems to be the main focus of the lecture, There is still a great deal on the history and science of brewing.
To save you a good couple hours of reading, I will refrain from summarising the entire lecture booklet. I will, however, transcribe a few selected quotes that I enjoy, maybe with a bit of background information, if you're lucky...

The first quote I would like to share comes from a section about brewing history. More specifically, it is from an article in a journal - Annals of Chemistry, 29, 1839 - published by Friedrich Woehler and Justus von Liebug, who wished to describe their solution to the mystery of alcohol fermentation:
"Beer yeast, when dispersed in water, breaks down into an infinite number of small spheres. If these spheres are transferred into an aqueous solution of sugar they develop into small animals. They are endowed with a sort of suction trunk with which they gulp up the sugar from the solution. Digestion is immediately and clearly recognisable because of the discharge of excrements. These animals evacuate ethyl alcohol from their bowels and carbon dioxide from their urinary organs. Thus one can observe how a specifically lighter fluid is exuded from the anus and rises vertically whereas a stream of carbon dioxide is ejected at very short intervals from their enormously large genitals."
Not long after, Louis showed that the yeast itself was responsible for fermentation. Not tiny animals with huge genitals.

Pasteur played a main role in the elucidation of beer diseases;
"We have in our power to prepare a beer which shall be incapable of undergoing any pernicious fermentation whatsoever"
Pasteur saved the French beer industry (that was quickly being surpassed by that of Germany) by identifying bacteria as the agents of beer spoilage, and then developing pasteurisation to preserve bottled beer.

Without fermentation using yeast, certain molecules and flavours are not produced or modified, and our beer would be very, very different (of course, it would still be called wort). This is something Pasteur could appreciate.
"It is easy to show that finished wort has a decided flavour and aroma of hops, as well as a sweet taste, and that it leaves a certain pleasant, bitter after-taste on the palate. When we taste it in this condition we cannot help thinking that a liquor of the kind, after fermentation, ought to constitute a very valuable beverage, as wholesome as it is pleasant" (L Pasteur).

Undoubtedly I could go on an on, writing about the life of Louis and his work, but alas, there are a set number of hours in a day and I already feel this post is too long!
I'll finish up with a suggestion; Next time you sit down to enjoy your beer, give a little toast to the scientists like Louis Pasteur and Jean-Pierre Dufour, who helped to perfect our brews.
Cheers!