The barrel
Wash and disinfection of the Trunk says of brewery

The brewery keg is a large-capacity returnable primary packaging (several dozen liters). They have been made of metal ever since wood was banned from their manufacture. At that time, there were beer kegs made of powder-coated steel, aluminum or stainless steel, with a biconical shape reminiscent of the wooden barrels of our ancestors. Today, beer kegs are made exclusively from AISI 314 stainless steel or, in smaller quantities, AISI 316 stainless steel.

This metal drum has adopted a cylindrical shape to facilitate mechanized operations, manufacturing, packaging and palletization. In France, it is available in volumes of 20, 30 and 50 L, and can withstand high pressures of 6 to 7 bar.

The...