Your Guide to Using Pottery

Using our pottery at Ringler Studios requires an understanding of safety measures. Generally, pottery glazes come in two different flavors, food safe or not food safe. What does that really mean?

Some variables are present in determination of "food safe". High temperature in pottery terms means the number of cones, normally a temperature at or above cone 6 is sufficient to make glazes food safe as long the ingredients of the glaze is non-toxic.

Ringler Studios use cone 10 (very high heat) in our firing process. This heat transforms the glaze into a fine particle glass. This, the higher heat (cone 10) creates a harder finer glass. This should but be the end of the issue, but the makeup of the glaze should be discussed. A primary element of crystalline is a mineral called zinc oxide, that makes the "crystals" in crystalline. This ingredient could be toxic if it leaches into your food. Additionally, some mineral colorants such as cobalt, titanium dioxide, and others are toxic as well.

What does all of this mean? Does it mean that I can not use my crystalline platter for serving food? Well, we need to look a bit deeper into that question. Remember, crystalline glaze at cone 10 for a fine glass on the surface of the pottery. That glass (basically silica) will protect foods in the contact of the glaze, but over time and use, micro-fissures can render a safe surface into a potential hazard.

It seems to be all of an issue of common sense. Soft or semi-soft foods are not recommended to be used on crystalline surfaces. Cheeses, dips, jellies, etcetera, should only be used on "Food Safe" glaze, however, if you wish to serve a dry food such as crackers or pretzels, the minerals should not leach into these foods.

To add a secondary element of safety when using a crystalline surface, we recommend covering the platter, bowl or serving plate with a linen cloth of plastic food-safe cover between the pottery and your food.