The kaiku is a one-piece beech or birch container especially designed to facilitate milking goats and sheep. Cone-shaped, the top is wider than the base. Unusually, its handle faces inwards, which allows it to be held with one hand.

 The kaiku has been traditionally used by Basque shepherds to make cheese and curd or “kallatua”.

As early as the Palaeolithic, shepherds cooked milk and water with hot stones they put into these bowl-shaped vessels which are still made by mountain craftsmen.