Oh, if only I had a penny every time I was asked if my pottery is dishwasher safe! The pottery that I make is dishwasher safe, but not all pottery is…
Whether you’re curious about how to care for your favorite pottery mug or have picked up some beautiful ceramic pieces at a thrift store, it’s a good idea to have an understanding of dishwasher safety with regard to different clay bodies and glazes.
In order to make a decision whether to handwash your ceramic piece, it’s important to be able to identify the three most common types of pottery, the type of clay used to produce them, and how they are glazed and fired. You can also scroll to the summary below!
Please note: I hope that you find some helpful tips in this post but please do ask the maker of your piece or a local potter for advice in identifying if your ceramic ware is dishwasher safe!
Broken down roughly, there are three main types of pottery, each made using different types of clay.
- Earthenware clay – fired at low temperatures
- Stoneware clay -fired at high temperatures
- Porcelain clay and its counterparts – fired at high temperatures but not as common nowadays
Earthenware, sometimes also called terracotta, meaning ‘baked earth’ is fired below 1200°C. Because it is fired at lower temperatures, earthenware is relatively soft and capable of being scratched with a sharp knife, it also tends to be more easily chipped. It is considered to be one of the softer ceramics. Raku is another type of earthenware.
And due to its porosity, with water absorption of 5-8%, must be earthenware must be glazed to be watertight; At least in the areas that will come in contact with food.
Is earthenware dishwasher safe?
It is advisable to handwash earthenware pottery in warm water with mild dish soap.
Although, it is perhaps beneficial to wash earthenware in the dishwasher from time to time as the high temperatures will kill any germs that may otherwise survive on any porous surfaces.
Stoneware is a rather broad term for pottery fired at a relatively high temperature. Though dense, impermeable, and hard enough to resist scratching, it differs from porcelain because it is opaque. It may be vitreous or semi-vitreous depending on the clay used and the temperature it is fired to. It is usually grey, brown, or white and may be glazed or unglazed.
If you ask even experienced potters, they may not be able to advise if a piece of pottery is earthenware or stoneware. If you are purchasing a new piece, it is very helpful to ask for this information!
Is stoneware dishwasher safe?
Stoneware is very hardwearing, and most pieces ( if they don’t contain gold luster as part of their decoration) tolerate being cleaned in the dishwasher, although regular cycles though strong detergents may, in time, alter the luster of the glaze. Some glazes and decorations are softer than others. You can read more about this and food safe ceramics below.
It may be difficult to avoid chipping the rim of very thin stoneware dishes, and handwashing with care is advisable for these pieces.
Nowadays, most handmade ceramic dinnerware and kitchen ware are designed with dishwasher safety in mind!
I work only with stoneware clay and my own glazes are food-safe and acid resistant glazes. I design each ceramic piece for use in our busy home and to withstand heavy use, including the dishwasher and microwave! In my experience, many potters who sell their work are of a similar mindset. Though stoneware clay is generaly more expensive to buy and fire than earthenware clay, it is more durable.
Porcelain is described as being “completely vitrified, hard, impermeable (even before glazing). Porcelain clay is white or artificially colored, translucent (except when of considerable thickness), and resonant”. So though it may be thin, it is likely rather strong and chip resistant.
Is Porcelain dishwasher safe?
Porcelain is a strong clay that should be ok for dishwasher use if not decorated with delicate glaze or metallic details. Working with porcelain requires alot of skill, and newly produced pieces are often very expensive. It might be better to be on the safe side and wash your pieces by hand.
So… Is Pottery Dishwasher safe?
Porcelain should stand up well to dishwasher use. This said, porcelain is often decorated with delicate glazes and hand-painted details, including gold luster. These do not tolerate regular dishwashing and are best washed by hand.
Stoneware – hard and vitreous tolerates dishwasher use. If it is a special piece or a piece of high value, you may consider hand washing to ensure the longevity of the glaze.
Earthenware – soft, absorbent, and sensitive to knocks and bumps. Occasional cycles in the dishwasher may be beneficial as the high heat aids in killing any bacteria lurking on unglazed surfaces. Otherwise, handwashing is advised.
Porcelain – tougher than it looks! Tolerates regular dishwashing depending on how it’s decorated.
Ceramic glazes that have gold and silver decals and lusters and other metallic glaze do not stand up well to dishwasher environments and are best hand washed.
Some other factors to consider when deciding dishwasher versus handwash
- Most dishwasher soap is moderately basic, but rinse aid is mildly acidic and may damage the delicate glaze.
- Matte glazes tend to be less tolerant of abrasive detergents.
- Is your pottery piece handmade? Often handmade pottery is signed, and it may be possible to contact the ceramic artist who produced the piece and ask for advice.
- Antique pieces can have micro damage and crackling in their glaze – the perfect breeding ground for microorganisms. These pieces, if not purely for decorative use, are best washed in the dishwasher on a hot wash cycle with a mild dishwasher detergent.
- Larger pieces and large ceramic plates may risk being knocked by dishwasher arms, which may cause chips depending on the clay body used. I recommend that you check that the piece fits comfortably in the dishwasher by test-spinning the arms.
- Handmade ceramics are most often not made to withstand temperature changes. This is worth bearing in mind even when handwashing, but some forms of baking dish are specifically made to be seasoned.
Seasoning unglazed pottery – A piece that is at room temperature is coated lightly with oil and placed in a cold oven which is then heated so as to avoid sudden changes in temperature.
(Thermal shock can crack even a stoneware piece! ) Continual use will naturally season these dishes..
Wash seasoned pieces with hot water and no soap. This will allow oils baked on it to build up and create a layer that protects the clay with each use and makes cleaning off food easier.
As a general rule, allow your dish to cool completely before washing to avoid temperature shock!
SAFE CERAMIC WARE
An easy way to find out if your glaze is ‘strong’ is to do a lemon slice test. This test is helpful in deciding if a piece or set may be dishwasher safe, and even food safe. I’ll go into more detail below.
Place a small slice of lemon, or a drop of lemon juice, overnight on new pottery pieces.
If the underside is glazed with the same glaze then it is best to place the lemon slice there as it may cause slight discolouring or a dull finish. If the bottom of the piece is unglazed then choose a discrete spot to do the test.
Safe glazes will show no change in the glaze structure or appearance after the test and will most likely tolerate the dishwasher environment well.
This test can also be done on ceramic dishes to test for the likelihood of a glaze leaching if used to serve acidic food.
Some glazes, in pieces older than 1970, can contain lead and other toxic chemicals which can leach into the food.
Lead is not commonly used nowadays but can be found in glazes nonetheless, and a soft glaze is, therefore, unsafe for food. Nowadays, most glazes are acid-resistant glazes and lead free glazes, but when purchasing older pottery, it is wise to be on the safe side. It may also be a good idea to purchase a lead test if you have any doubts.
Lastly, some advice expert advice from experienced potters :
“Here are the rules: do you want it to look the same for a long time? Hand wash!”
“Life’s too short to wash dishes by hand, my time is more precious than any wares I use”
“We have a rule in our house, only things we don’t care about go in the dishwasher. Everything we do care about is hand washed.”
” I microwave and dishwash both stoneware and porcelain. Never had any problems with either one. “
Whichever way you choose to wash your pottery, it’s worth remembering that their purpose is not only functionality. They are created to spark joy in their use, and if handwashing puts you off using them, one might consider breaking the ‘rules’…
I would love to hear your thoughts in the comments below!
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Hi, I’m Holly!
I want this space to be a source of wisdom, inspiration, and delicious recipes. Whether you’re looking to discover a new hobby or simply craving a great recipe, I hope you’ll find something that sparks your interest here!