In Lille, where Calmette spent most of his life, meals are not a succession of starter-main-dessert but revolve around a single hearty dish, slow-cooked in beer and shared at the large table of the estaminet, followed by a pungent cheese and a brown-sugar sweet. To this Flemish table I have added two stopovers from the scholar: the hot chickpea pancake of his Nice childhood, eaten standing in the street, and the fermented rice of Saigon, where he studied the ferment that transforms starch — a perfect bridge between his laboratory and the pot.

Sourdough, brewer's yeast, Chinese rice ferment: fermentation is the thread running through Calmette's work. The bacteriologist who isolated the BCG bacillus also spent months in Saigon unraveling the secret of the microorganisms that make dough rise, beer foam, and rice alcohol come to life. At his table, what bubbles in the test tube ends up in the glass and on the plate.