Skins

The ancient Eastern tribes who were nomadic shepherds preserved their milk, from cows, sheep, goats, horses and camels, in containers made from these animals' skins or from their stomachs.

Legend tells that yogurt was discovered because a shepherd, forgetting some milk in one of these skins for a while, when he finally remembered it, found it transformed : into something denser and tastier.

As far as Yogurt is concerned, it is easy to isolate the main cause of fermentation in the organisms present in the animal skins used as containers.