Pasteurization and Wine Diseases

On 23 January 1860, the Cobden–Chevalier Treaty, an Anglo-French free trade agreement, was signed between Great Britain and France. The treaty ended tariffs on various items of trade, silk, wine, and brandy from France, and industrial goods, coal, and iron from Britain.

Consequently, it drastically enhanced the wine exports of France. However, it turned into a national crisis when most of the wines turned out to be spoiled. These wines were cloudy, slimy, and bitter and were known as maladies.

Examining Spoiled French Wine

Due to the crisis created by spoiled wine, the French economy and reputation were under serious threat. In 1863, Napoleon III, the French Emperor, commissioned Louis Pasteur to explore a cure to the issue of spoiled wine. Subsequently, Fàve sent a formal request to Pasteur that he quickly accepted and started his work. However, Pasteur soon encountered the problem during his work on fermentation.

First, he examined spoiled wine and indicated that each wine disease was attributed to a specific ferment. He formulated a strategy to tackle the diseases and heated the wine at 55 -60°C. At these temperatures, unwanted organisms in the wine were killed, which extended the wine’s shelf life.

Moreover, the wine did not deteriorate, and its bouquet was maintained. This method is now famously known as pasteurization and is common throughout the beverage industry. In this way, Pasteur salvaged the dwindling French wine industry and export.

Pasteur used this machine to cool and ferment beer

On Louis Pasteur

Louis Pasteur was born on 27 December 1822 in Dole, France. His father was a tanner of leather, and his family was indigent. Although he was an ordinary student at school, he was brilliant in painting and sketched portraits of his family members. Later, he completed degrees of Bachelor of Science and arts and a doctorate in science at 25. Due to his meteorological success in education, he was offered the post of chemistry professor at the University of Strasbourg soon after his graduation. In 1854, he became a professor and dean of the faculty of science at the University of Lille.

In 1856, he was commissioned by M. Bigot to explore what was spoiling beetroot alcohol. After evaluating various samples under the microscope, Pasteur discovered that spherical yeasts and rod-shaped microorganisms were present in alcohol. He concluded that a specific microorganism, called Acetobacter aceti, converted alcohol to acetic acid.

Also read: Why Did Romans Use Sulfur Inside Their Wine Vessels?

Pasteur conducted several experiments on alcoholic and lactic acid fermentation, concluding that fermentation was not a spontaneous reaction due to enzymes as was commonly believed at that time. He could successfully establish the fact that fermentation was due to these microorganisms. On 20 April 1862, he performed his test of boiling and then utilized a cooling technique of wine to kill undesired bacteria.

Not only the wine industry, but Pasteur also helped rescue the silk industry. Moreover, he invented vaccines for Rabies and Anthrax. Consequently, due to his ground-breaking research and discoveries, he was named as ‘Father of Immunity.’

Pasteur’s Winemaking

Pasteur’s family possessed many vineyards they used to make wine for personal use. In 1878, he purchased a vineyard and constructed a laboratory to continue his research work. Later on, he extended the vineyard to nearly half a hectare by 1892, three years before his death.

According to Pasteur,

Wine is the most healthful and hygienic of all beverages.

Pasteur also stated,

A bottle of wine contains more philosophy than all the books in the world.