How can you tell if hand-made pottery is dishwasher safe?

I’ve got a few hand-made clay mugs and dishes and such. Will they be damaged by being put in the dishwasher? I have this instinctive reaction that hand-made stuff is more fragile, but then I think, they got fired in a really hot kiln and have a regular glaze, so maybe I’m just being silly.

Is there any way to tell what pottery is dishwasher safe and what should be hand-washed?

Pottery is always dishwasher-safe, unless it’s absolute crap. BUT (you knew there was going to be a “but,” right?) be sure when loading it that no piece has enough freedom to move and bump into another. And be aware that many detergents formulated for automatic dishwashers contain a fine abrasive which will, over time, fog and dull the glaze finish.

Well, the pressure of the spray and the detergents are the risk, not the heat.

It might be a cumulative effect over time, which is hard to test. After a few dozen washes, there might be issues…fading…wear, etc.

A large manufacturer would have data around the types of finishes that are durable and would have stamped “dishwasher safe” because they have labs to test things.

So, it is hard to answer, but my instinct is to say, “Yes”…it is safe for the dishwasher. The finish and material might be better suited than most others. Dishes, etc that are mixed of plastics, or have handles that are glued on, or have certain designs that are not embedded into the material or covered with a tough glaze are one the ones that probably aren’t safe.

Stoneware generally can go into the dishwasher (looks greyish with flecks in the unglazed area.)
Earthenware generally can’t because it can swell and flex too much with the heat (looks red with flecks in the unglazed area). It might be ok, or it might not; risky. Earthenware also cannot go directly into a hot oven, but must be brought up to heat with the warming oven.
Porcelain can go in the dishwasher but is really fragile and likely to break (looks white or light grey without flecks in the unglazed area; also, often goes “tiiing” when tapped with a fork.)

so, not the heat, but the humidity?

thanks for the answers, everyone.

In the kiln the pottery goes up to 2000 degrees, the heat of the dishwasher isn’t going to cause a problem. The problem, as mentioned above, comes from the glazes or if the piece is particularly fragile.

One other big caveat, some types of pottery are not vitreous (fully fused and all spaces filled with a glasslike substance) and shouldn’t go in the dishwasher. Earthenware is mentioned already, but there are other types. Ask the potter to make sure if you don’t know.