1971 Bay Keramik Romertopf (W. Germany Nr. 109 Amerika). In 1970 Bay patented the RÃ¶mertopf â a clay cooking pot which works by steaming foodstuffs and allowing them to braise in their own juices, billed as the healthiest way to prepare meals. In 1971/2 Bay ceased to exist and they changed their name to RÃ¶mertopf and only produced clay cooking pots. RÃ¶mertopf claim to have manufactured over 25 millions cooking pots.