Earthenware

Clay is simple, a blend of an array of minerals such as silica, calcium, iron, and many more defined by its fine particle size. Finer than sand but coarser than silt, most of us have a general understanding of what clay is. But when we're talking about pottery, there's much more to know.

Sometimes pottery is marked as porcelain, stoneware, earthenware, and on the rare occasions raku or fireclay. What's the difference, and is one better than the other? I don't think any is superior because they each have their use.

Earthenware is a "low-fire" clay. It matures, meaning its components bond as tightly as they're going to before it begins to melt, at relatively low temperatures in the kiln. This is still around 1,000 degrees Celsius. True earthenware never vitrifies, so it will always remain fairly porous. Think terracotta plant pots. They have been fired to maturity and no amount of water can make the fired clay dissolve, but an unglazed earthenware piece still allows air and water to pass through it.

Earthenware is often weaker than stoneware or porcelain but still makes beautiful functional pottery. Being porous, it is also more resistant to heat shock, which is very useful indeed for cookware. Maturing at lower temperatures also makes it a little more environmentally friendly than higher-fired clay types.

If you see a piece that is brick-red to chocolate brown in its unglazed areas, like the bottom, it could well be earthenware. But not necessarily! I like to work in both red and snow-white earthenware, just for the heck of it.