Why Do Plastic Containers Never Dry in the Dishwasher?

Updated: Jan. 25, 2024

Putting the dishes away is enough of a pain, having to hand dry your plastic ware makes the task even worse.

If you’ve ever lived without a dishwasher, you know how amazing of an invention it truly is. It scrubs off the food grime and leaves your dishes sparkly clean and ready to be put away. But all of the plastic plates, cups, and storage containers seem like they skip the last part of the washing cycle and never fully dry. Why are all your plastic containers and dishes covered in beads of water? No, it’s not because you have a cheap or broken dishwasher—there is actually some science behind it.

Adam Hofmann, Director of Engineering, Dishwasher Advanced Systems at GE Appliances, gave Reader’s Digest the inside scoop. These are the items you should never out in your dishwasher.

“Plastic items are more difficult to dry because they have a lower thermal mass than ceramic or metal items in the dish load, causing them to cool faster than the other items during the dry portion of the cycle,” says Hofmann. “Once the surface of a dish cools, the moisture on the surface is less likely to evaporate into the air and be removed by the dishwasher dry system.”

Since your glass, metal, and ceramic dishes absorb and retain more heat during the dishwashing cycle, they can easily evaporate leftover water droplets. Plastic doesn’t get as hot, so the water droplets stay and never fully dries.

Hofmann adds that this happens because “the standard dish load used in developing most dishwashers does not include plastic items that consumers actually use.” However, GE saw customers frustrations and recently developed Dry Boost and Twin Turbo Dry Boost technology which dries all dishes, including plastic. The appliances use a dual-wattage heating element and smart algorithms to adjust the level of heat and the time of drying for maximum efficiency and reliability.

If you’re not in the market for a new dishwasher, but want one of your most-used appliances to treat your plastics better, make sure you’re using a good detergent, that you’re letting the dishes run a full cycle, that you place your plastics on the top rack only, and that you’re avoiding these ways you’re loading your dishwasher wrong. It won’t completely solve the problem of having to hand-dry your plasticware, but it will help.