Containers made of this material are used as an alternative to oak wood, stainless steel or natural stone (granite) for fermenting and storing wines. The conventional concrete containers are mostly lined on the inside with glass tiles or stainless steel sheets, more rarely with plastic or coated with varnish. The advantages are optimal use of space, flexible volumes and low shrinkage. Since the mid-1990s, experiments with egg-shaped concrete containers have been carried out, starting in France and then in Spain and now also in Germany. In the German wine-growing region of Franconia, some winegrowers are using such "concrete eggs" with a volume of 900 litres.