Remember that ale mugs can be made of wood too. Why would you do that you ask? You ever held a German "Humpen" in a ceramic mug or a half liter beer glass? Because you don't hold a full one very long. They are *heavy* (Visit Oktoberfest if you ever want to try your luck).
If they make this ceramic or metal and it's a Humpen sized one, you are doing muscle training with each sip
