In all his years in the beer industry, Keith McAvoy had never taken much professional interest in Coco Pops.

From time to time, Mr. McAvoy, who runs the craft brewery Seven Brothers in Manchester, England, would raid his children’s supply of the chocolate-flavored breakfast cereal for “a cheeky bowl” or two — though only, he said, “when nobody was looking.”

Recently, however, Coco Pops have become more than a guilty pleasure for Mr. McAvoy.

For the past seven months, Seven Brothers has been using breakfast cereal to make beer. The aim of the venture is nobler than the inevitable “beer for breakfast” jokes might suggest: namely, to address — even in a small way — the global issue of food waste and its effect on climate change.