ivan_erohin
"By the 15th century, the Worshipful Company of Pewterers controlled pewter constituents in England. This company originally had two grades of pewter, but in the 16th century a third grade was added. The first type, known as "fine metal", was used for tableware. It consisted of tin with as much copper as it could absorb, which is about 1%" (c) по ссылке.

Так что все мы правильно написали. Волшебники, конечно, психи, но не идиоты, чтобы использовать для варки зелий свинцовый пьютер.