Dr Karl explains why plastic containers are never dry after being cleaned in the dishwasher
By Rachael Gavin|
Many of us know the frustration of opening the dishwasher when it's finished to find almost everything dry, except plastic containers.
Unlike our plates and bowls, plastic containers are often covered in water droplets that threaten to drip all over the other dry items.
Thanks to beloved Australian scientist Dr Karl Kruszelnicki we now know why this category of kitchenware is always wet after being cleaned in the dishwasher.
Dr Karl explained in a TikTok video for Triple J that there are two reasons why plastic containers stay wet after being in the dishwasher.
Watch the video above.?
Before delving into the science behind this drippy phenomenon, Dr Karl gave some background on how dishwashers work.
He said once the dishwasher has finished washing your dishes it has a heating cycle, which is aimed at evaporating the water on the dishes.
While plates have a "high specific heat" because they are large, heavy and ceramic , plastic containers are light so they have a "low specific heat", and this is why plastic items remain wet.
"The plates are loaded with heat and they evaporate, evaporate and get rid of their heat and part of the way through the cycle all the water has gone off?," Dr Karl said.
"[A plastic container] ?has hardly any stored heat and it uses it all up and there are still droplets left behind."
READ MORE: Why travellers are loving this $65 K-beauty skin serum
Another reason plates end up dry and plastic containers don't is because of the substance they're made from.
Many plates are ceramic and so when the water hits them it "spreads out into a thin film and evaporates from the surface really easily because you've got a large surface area".
As for plastic containers, Dr Karl said they're made from oil?, which doesn't mix well with water, so when the water hits the plastic container it goes into droplets instead of spreading out.
Plastic containers also don't have much surface area? so the droplets stay instead of evaporating.
READ MORE: The verdict on whether dishwasher tablets or powder is best
To deal with our wet plastic containers, Dr Karl recommends shaking them out over the sink and drying them with a tea towel. He also joked that you can leave them to dry next to the sink for someone else to sort out.
READ MORE: 20 mistakes you could be making when using your dishwasher?
?There are other hacks and tips that can help your dishes dry better in the dishwasher.
Some people swear by putting a tea towel over the top of the dishwasher door after it's finished to absorb excess moisture.
You can also open your dishwasher door when it's finished running to allow the steam to escape if you don't have a machine that opens automatically.
Adding rinse aid to your washing machine also helps, so if more dishes than just your plastic containers are wet after a run in the dishwasher make sure your rinse aid compartment is topped up.
Failing those hacks, you can wash plastic containers by hand in the sink, which is often recommended for them anyway to maintain their quality, and then dry with a tea towel or leave on a drainer to air dry.?
?For a daily dose of 9Honey, subscribe to our newsletter here.
