Earthenware jars are a type of pottery that has been used for centuries. Ollas (5 letters) are earthenware jars with a wide mouth and narrow base, often used for storing and cooking food. Crocks (6 letters) are earthenware jars with a wide mouth and thick walls, often used for fermenting and storing food. Both ollas and crocks are made from clay and fired in a kiln, making them durable and watertight.