Why Some Cuisines Rely Heavily on Fermentation

Long before anyone owned a refrigerator, cooks discovered that the surest way to save food from rotting was to let it rot on purpose, carefully.

That paradox explains why fermentation sits at the heart of so many of the world's most distinctive cuisines.

Fermentation is simply controlled decay: bacteria and yeasts consume sugars and leave behind acids, alcohol, and carbon dioxide.

Those by-products lower the pH enough to make the food inhospitable to the microbes that would otherwise spoil it.

Geography did much of the deciding, since cultures facing long winters or humid summers needed preservation more urgently than others.

Korea buried cabbage in earthenware jars to survive months when nothing green would grow, and [kimchi] became a national institution.

In [Japan], the mould [koji] transforms rice into the foundation of [miso], soy sauce, and [sake] - a single organism underwriting an entire flavour vocabulary.

Northern Europe leaned on lactic acid and salt for herring and rye bread; The Levant turned milk into yoghurt and [labneh] that keep without cooling.

Preservation, however, was never the only reward: fermentation manufactures glutamates and free amino acids - in short, umami, the savoury depth that makes fish sauce indispensable in Southeast Asian kitchens.

It also does some of [digestion's] work in advance, breaking down lactose, hard-to-absorb plant compounds, and tough fibres before the food reaches the table.

Communities that fermented widely tended to eat better on thinner harvests, an advantage that quietly favoured the habit.

Taste, meanwhile, is learned; What strikes an outsider as pungent registers to a local as home.

Every jar of [kimchi] or bowl of [miso] is a piece of inherited engineering, worked out by cooks who had no microscope and no word for bacteria.

Perhaps the most remarkable thing is how appetising their invisible collaborators turned out to be.