Earthenware Glaze Guide


All earthenware pottery for domestic use is glazed, as this prevents liquids seeping through the porous ceramic. There are lots of different types of glazes, that all have a slightly different effect on the finish. The first earthenware pottery designed for holding food and liquids is thought to have originated from around 10,000BC, and the idea of glazing was discovered some two thousand years later. We’re going to take a look at some of these glazes, their benefits, and the best way to keep them clean and safe.

Salt Glaze

Salt glazed pottery has a glassy shine, whilst retaining its distinctive earthenware appearance. It was created by throwing salt into the kiln during the highest temperature part of the firing process. The earliest known production of salt glaze pottery took place in Germany in the late 13th century. The process produced a large amount of air pollution, and feel afoul of clean air regulations made in the 20th century.

Ash Glaze

Ash glaze is a much earlier form of glaze, still used today, that began in around 1000BC in China. The potters realised that the ash from the kiln that was landing on the pots during the firing process was leaving a green coloured glaze, so they began covering the pots in the ash before they were put in. The more ash that is used in the glaze, the different the colour that can be achieved.


There are two different types of pottery that carry the majolica moniker. One is a tin-glazed type, which has a silvery white shiny, and opaque covering which originated in the 9th century, and was the first to be called majolica.

The second is the much later British, lead-glazed pottery that was first produced under the name Palissy Ware in the mid-19th century. This is a very different style, made in a completely different way, but the public began to refer to it as majolica and the name stuck.

Caring for your Earthenware

If your earthenware has been made recently then it is very likely that it will be completely fine for dishwasher use, and should say so. You should be careful to look out for any cracks in the glaze however, known as ‘crazing’, that take the form of a spider-web pattern. These cracks give access to the soft porous ceramic beneath, so extra care should be taken with any crockery showing signs of this. If your earthenware crockery is suitable for dishwasher use, then make sure you wash it with Finish Quantum Shine & Protect to help clean away grease and dirt that may have built up.