What specialized craft, often passed down in early cultures, required expertise without formal scientific authority?

The technique for salting fish

In many early coastal or nomadic societies, specific food preparation techniques were preserved through strict tradition rather than formal scientific instruction. The text highlights the example of salting fish, noting that the exact technique for achieving successful preservation was transmitted as an unbroken tradition, functioning much like a specialized craft. Individuals mastering this technique possessed a high degree of practical expertise in application—knowing precisely how much salt to use and for how long—but they did not necessarily possess a formal, theoretical authority in the sciences, specifically microbiology or chemistry, that explained *why* osmosis or reduced water activity worked to inhibit spoilage.