Beers and wines

How to prevent beet alcohol from turning sour?

This challenge is at the origin of twenty years of work and discoveries by Louis Pasteur on the fermentation of wine or beer.

At a time when the quality of wine was of concern to Napoleon III, Louis Pasteur showed that heating this drink denatured the problematic ferments and allowed it to be kept intact in the bottle.

A process that has become famous: pasteurization.

His work on fermentations and micro-organisms, which refuted the theory of spontaneous generation, then opened the doors to microbiology and vaccination.

They also provide the foundations for the hygienist movement of the 19th century.

Worms (silk), sheep, chickens

Around 1865, Louis Pasteur turned to animal diseases.

First, silkworms, at the request of a senator from Gard, where the silk industry was decimated by pebrine.

The researcher discovers the parasitic origin of this disease and develops techniques to make farms more hygienic.

Bottles presented in the museum of the Institut Pasteur, in Paris © STEPHANE DE SAKUTIN / AFP/Archives

Next step: the hens, sick with cholera.

The scientist discovers, inadvertently according to the legend, that it is possible to attenuate the virulence of the germ at the origin of the disease.

Better, the gallinaceans contaminated by an attenuated germ will be protected against a new infection.

Then, anthrax, which affects sheep but also humans (shepherds, etc.) in contact with their remains.

On the same principle as for cholera, the researcher developed a vaccine based on the germ of weakened anthrax which he tested on sheep - in front of the press - in 1881.

Vaccine: of rabbits and men

At the turn of 1880, Pasteur launched an attack on rabies.

He first studies the transmission of the virus, then seeks to reduce its virulence, this time on living animals.

He passes the virus from rabbit to rabbit and lets the marrow of inoculated animals age in flasks exposed to the air.

Pasteur tests his vaccine on rabid dogs: it is a success.

But he is hesitant to move on to being human.

The first test took place on July 6, 1885, on Joseph Meister, a 9-year-old Alsatian boy bitten 14 times by a rabid dog.

The boy, who receives several inoculations containing rabies rabbit, does not develop the disease.

Statue of the head of Louis Pasteur in front of the Institut Pasteur museum in Paris © STEPHANE DE SAKUTIN / AFP/Archives

Second test, and confirmation, in September, with the vaccination of a 15-year-old shepherd, Jean-Baptiste Jupille, bitten by a rabid dog.

Louis Pasteur made this success widely known - others before him had tried to vaccinate - and a multitude of "buffs" came, from France and abroad, to be vaccinated.

Joseph Meister will become a caretaker at the Institut Pasteur.

Napoleon, the Republic

Son of a sergeant in Napoleon I's Grande Armée, Louis Pasteur was enthusiastic about Napoleon III from 1848 onwards.

His praises redouble before the interest of the Emperor and his wife Eugenie for the sciences and their applications.

The scientist, patriot and conservative was thus called upon to solve the problems of French wine.

After the fall of the regime, Louis Pasteur finally rallied to the Third Republic - which put down the Commune.

In a France marked by its defeat in the war of 1870, the scientist became one of the figures of the cult of great men.

He is also celebrated during his lifetime as a benefactor of humanity (Pope Leo XII sends a message of congratulations for his 70th birthday).

When he died on September 28, 1895, the government organized a state funeral.

On the other hand, the family refuses the Pantheon, and buries the scientist in a crypt under the Pasteur Institute.

Entrepreneur

Louis Pasteur is sensitive to the practical aspect and the economic interest of his research.

His work sometimes meets the demand of industrialists, such as for fermentations or silkworms.

Wine, beer or animal vaccines, the scientist also filed a number of patents on principles with an industrial application.

And he makes substantial gains from it.

After his discovery on rabies, he created the Institut Pasteur, thanks to an international subscription.

Inaugurated in 1888, this private foundation recognized as being of public utility is dedicated to vaccination, research and education.

It will spread to several countries.

© 2022 AFP