What is a "Kiln Kiss"?

Kiln kisses are the special drips, bubbles, bare spots and warping that make each handmade ceramic piece truly one-of-a-kind. They have no impact on the structural integrity or food-safety of a finished piece.

In the pottery process you can only control so many aspects of creation, and the rest are left up to what we potters call "the kiln gods." This is why I decided to call these glaze variations "kiln kisses."

So how does it happen?

Drips

Drips can be either intentional or incidental. Some glazes are specifically formulated to cause drips. Unintentional drips can happen when a piece is loaded into the kiln and fired before the glaze has dried completely. This occurs because the remaining water content in both the glaze mixture and the water absorbed into the pottery while glazing make it more difficult for the glaze to adhere to the pottery.

Bubbles

Bubbles usually happen as a result of uneven heating or firing slightly hotter than the ideal temperature for the glaze. If they are on the inside of a food or drink vessel they can cause issues with food safety through trapped bacteria or moisture. This is why I use reliable, tried-and-true glazes on the inside of my functional foodware to minimize the amount of pieces lost to quality-control checks for internal bubbles. Whenever I get kiln kisses that are bubbles on the outside of a piece I will sand them. This leaves an interesting moon-crater texture and prevents any moisture or bacteria being trapped.

Bare Spots

Bare spots commonly are a result of glaze that was applied too thick or not dusting the piece before glazing. As long as the ceramic is fired to vitrification (heated until the clay is no longer porous), small internal bare spots cause no issues with food safety. I view them like cute little freckles.

Warping

Warping happens when there is unintentional force exerted on a piece while it is still wet or leather-hard. (leather-hard is the condition of a clay body when it has partially dried to a consistency similar to leather of the same thickness as the clay. This is the stage when attachments are made or carvings are drawn.) For wheel thrown items It commonly happens when a piece is newly finished and being taken off the wheel. For handbuilt items it is typically a result of over-handling flat slabs of clay before they are firm enough to move. Even if the clay is pushed back into the intended shape, the misshapenness can re-reveal itself after glaze firing.

For each item listing I am sure to include a description of any kiln kisses that appear on the piece. If I am selling an item I have deemed that the kiln kisses present have no impact on the structural integrity or food safety of that item.