question: What is made by placing a plate of blade of copper , brass , or bronze into vat of fermenting wine for several weeks , then scraping off and drying the green powder ?
answer: Verdigris
turker_answer: Verdigris is made by placing a plate or blade of copper , brass , or bronze into a vat of fermenting wine for several weeks , then scraping off and drying the green powder .
rule-based: Verdigris is made by placing a plate of blade of copper , brass , or bronze into vat of fermenting wine for several weeks , then scraping off and drying the green powder .