Ring of Truth

I was pretty young when I read a child-friendly biography of Louis Pasteur (1822-1895) , probably 11 or 12 years old. I do remember it being inspiring - at that age, in the right mood, anything seems possible, even "that could be me". I think it was enough to get me to pay attention in science lessons

I think I felt a bit of a connection because one thing he worked on was anthrax - a fatal disease of herbivores, including farm livestock, and occasionally humans. At the time, the fatalities were buried on farms where they died, and Pasteur showed that this contributed to the spread of the disease

UK had an outbreak of Foot and Mouth disease at about the time I was reading the book, with big impact on the lives and spirit of the farming community - a big impression on a young mind. Looking back, maybe that reinforced the significance of Pasteur and his work

He also worked on fermentation, and the different organisms that cause 'good' and 'bad' fermentation. Our cider is now bubbling nicely, with the introduction of a specially purchased cider yeast; thanks Louis. And he showed both that micro-organisms were the cause of many diseases and that vaccination with artificially 'weakened' forms of a disease provided protection against infection. My flu and Covid immunity should be hitting its peak about now so, again, thanks Monsieur

There was much more, including a series of experiments with 'swan-necked flasks' to disprove the hypothesis of 'spontaneous generation' (living organisms arising from non-living matter), that every school-child is told about

Out of all this, of course, arose the process that still carries his name - pasteurisation - applied by him to milk, wine and beer, and by us to apple juice. We heat the juice in a water bath to 75 degrees Celsius for 25 minutes then seal it. As Louis showed, that kills yeasts and bacteria in the juice, no new ones can get in, and spontaneous generation still doesn't happen; the juice will be fine for a couple of years. À votre santé, Professeur!