Are handmade ceramics and pottery dishwasher safe?

Pottery in the home

Handmade pottery is an art form that adds so much warmth and coziness to a home. Most people have at least one handcrafted ceramic piece in their homes. Artists collect other artists’ ceramic work. Art collectors curate their own personal stash of pottery. Even homebodies,like myself, have a few favorite handmade mugs to sip our morning coffee from. After all, coffee and hot tea just so much better from a cozy, handmade mug, right?

It’s clear that many people love handmade ceramics. However, many people have a hard time with discerning how to take proper care of their pottery. Some ceramic pieces, like vases or flower pots, are obviously not going to need much washing other than a quick rinse. What about the pots that we use daily? Do we hand wash our favorite soup bowl? Can our favorite ceramic mugs go in the dishwasher? What about the microwave? Many questions pop into our minds when it comes to caring for our pots. Sometimes we go with our gut, but we can unknowingly put our beloved pots at risk if we do things wrong.

Is pottery dishwasher safe?

The main question that most people seem to have is whether or not their pottery can go into the dishwasher. The short answer to this question is it depends. Without a doubt, the best way to take great care of your handmade ceramics is by handwashing them. That aside, in what situations is it safe to put pottery in the dishwasher?

The Type of Clay Matters

No two artists are identical in style, and likewise, no two handmade ceramics are the same. Potters and ceramic artists usually have a preference for what kind of clay they use to create their pieces. Some enjoy throwing porcelain clays while others love working with stoneware or earthenware clay. It is very important to know what kind of clay body your handmade pottery is made of when determining whether or not it is safe to put in the dishwasher. Usually the potter will provide this information, but you can always reach out to the artist if you are unsure!

Earthenware Clay

Earthenware clays are typically low fire clays that bake at a much lower temperature than stoneware or porcelain. Being a low fire clay body, earthenware is porous in nature. You won’t be able to see the holes in the clay necessarily, but they are there. When clay bakes at high temperatures, the porosity of clay significantly decreases and the clay is usually fully vitrified. This is important to know because how porous your pots are will determine whether or not they can go into the dishwasher.

When you have porous ceramics, they are more vulnerable to being damaged in a wash cycle. Dishwashers heat up and cool down in relatively short spans of time. When porous pottery goes through a fast or extreme temperature change, it is more likely to fall victim to thermal shock. Hot water causes expansion and cooler temperatures cause the pots to shrink back. When earthenware goes through these changes it basically means that your pots may develop weak points that could cause breakage. These breakage points are especially prominent in attachment points on pottery such as the handle attached to a mug.

Open pores in the clay also pose another problem. Dishwashers are obviously very wet at times because they use water to wash your dishes. Porous clays like earthenware allow microscopic places for your pot to stay damp and in turn, grow mold. The presence of mold compromises your ability to use your handmade pots for food and drink. In short, if you’ve got earthenware pottery, stick to handwashing! The risk to your pottery outweighs the convenience by far.

Stoneware and Porcelain

Stoneware and porcelain are both high fire clays that become almost fully vitrified in the kiln, meaning they have a very low porosity, if any at all! This makes pottery made of porcelain or stoneware a better candidate for going into the dishwasher. These pots are less likely to undergo thermal shock because they are baked at much higher temperatures than a dishwasher will reach. They also are unlikely to grow mold from the consistent water exposure. Even still, safely dishwashing stoneware and porcelain depends on a few additional factors.

The Type of Glaze Matters

The glass elements that make up ceramic glazes melt in the kiln at extremely high temperatures and form an almost protective, glassy coating on pottery. When the glaze and the pottery are compatible during the firing process, there will be very few opportunities for a weak point to form on your pot. There shouldn’t be any areas of crackling in the glaze and there shouldn’t be points where the glaze is super thin. If the glaze fits properly, then it should be able to go into the dishwasher with minimal worries.

However, stoneware or porcelains that have a crackle glaze are not suitable for the dishwasher. These cracks will allow areas for mold to grow just like a pot that is porous. The cracks can also create weak points when they undergo thermal expansion.

Crackle glazes and ill fitting glazes aren’t the only glazes unsuitable for the dishwasher. Porcelains and even stoneware at times can be finely decorated using metallic luster. Think of your grandmother’s fine holiday china. Does it have a gold or silver band around the rim? That’s luster!

Luster is an embellishment that contains actual heavy metals. It cannot go into the microwave, because it could spark just like silverware. It shouldn’t go into the dishwasher either, but not because of flammability. Gold or silver luster is fired on pottery last in the firing process and at much lower temperatures than normal glaze. Luster is delicate and can flake off or rub off in high heat. It is best to hand wash pieces that are metallic or have these fine decorations to keep them in good shape.

While it is always a good rule of thumb to wash your handmade pottery with a soft sponge, there are a few instances where it is completely safe to wash your favorite mug (top rack only of course!) It is a case by case basis. Just follow the guidelines above and use a washing detergent that isn’t too acidic, like bar keepers friend. Happy washing and keep on enjoying your handmade pots- that’s what they were made for after all!