The original barrel is an amphora. Barrels do two things when storing spirits, they add water and alcohol soluble wood components, and the provide oxidation reactions. Ceramic vessels can be made where they are essentially glass, like a porcelain tea cup, or they can be made where they leak water like with a flower pot. There are a few traditions such as awamori and pisco that use ceramic vessels for maturation. Does anyone have any information on how ceramic vessels are made for aging (types of clay, temperature fired) that can balance being porous enough to age, but not too much to loose spi