Breaching the Ceramic Wall

Spotted a massive white cylinder blocking the flank of my fort! Solid stone-like ceramic. Marched straight up, braced my boots, and shoved hard with both arms. Clink! Heavy as iron, filled with dark steaming liquid. Didn't tip over. Solid defense! Climbed onto a thick hardbound notebook to test its rim, but got blasted right in the snout by bitter, hot steam. Snorted loud! Left a rugged boot scuff on its glazed side to mark it as tough territory.