FYI, Rinsing Your Dishes Before They Go In The Dishwasher Might Just Leave Them Dirtier

If you see someone put their plate straight in the dishwasher without giving it a cursory rinse first, you may think they’re being lazy, trying to bypass a step. The reality? They’re probably doing it right. 

Holly Moore, founder and owner of in-home cleaning company Maids and Moore, told HuffPost that rinsing dishes before putting them in the dishwasher is a common mistake she sees people make in the kitchen. While you still should scrape food off the plate, rinsing your dishes is completely unnecessary. 

We reached out to home appliance experts about why rinsing dishes backfires (in most cases, at least) and other ways people unknowingly damage their dishwashers. Ready to get down and dirty? Let’s get into it.

Why rinsing dishes can do more harm than good 

Ian Palmer-Smith, an appliance repair expert at Domestic & General, told HuffPost that most dishwashers have a built-in food sensor that can detect how much food is on the dishes, which then signals to the dishwasher how long the cycle should be, as well as the temperature of the water. “So if you rinse the dishes off first, the dishwasher isn’t going to do as heavy of a cycle as it would otherwise,” Palmer-Smith explained, adding that this can cause grime stuck on dishes to not be cleaned off as well. 

The built-in food sensor is a beam of light that scans the dishes. If it senses a lot of food or grime, the dishwasher auto-selects a heavier cycle than it would otherwise. When the dishwasher is going through the cycle, Moore explained, most dishwashers flush the food particles out with the wastewater into the home plumbing system. However, some food may end up in a built-in food trap, which Palmer says should be cleaned about once a month.

It’s important to know that not all dishwashers have a built-in food sensor, but if your dishwasher was made in the last 20 years, it likely has one, according to Lee Gilbert, a home appliance repair expert and founder of home appliance spare parts retailer Ransom Spares.

How can you know for sure if yours has one? Moore said to check the user manual (which you can try to find online by Googling your dishwasher model type, if you didn’t keep the manual). “The user manual will typically list features of the dishwasher, including whether it has a food sensor. Look for terms like ‘soil sensor,’ ‘auto-sensing cycle’ or ‘smart sensor technology,’” she said.

Can’t find the manual? Moore recommended checking the dishwasher’s settings. “Dishwashers with food sensors often have an ‘auto’, ‘sensor wash’ or ’smart wash’ cycle. These settings indicate the dishwasher can adjust water use, temperature and cycle duration based on the dirtiness of the dishes,” she explained. If you still can’t figure it out, she recommends checking the manufacturer’s website and calling customer service to ask.

In addition to modern dishwashers having food sensors, Palmer-Smith said that detergent technology has gotten better at cleaning dishes — another reason why rinsing is unnecessary. “The enzymes in dishwasher cleaner attach themselves to food, so if you prerinse your dishes, it has less to attach to,” he explained.

How to keep your dishwasher in prime condition

Maybe you had no idea until now that your dishwasher had a food sensor. Has rinsing your dishes before loading it damaged the food sensor for good? Moore shared that continuously rinsing your dishes first can desensitise the food sensor. “Over time, consistently running the dishwasher with prewashed dishes can skew the sensor’s sensitivity or result in less effective cycles in general,” she said. 

So what can you do about it? All three experts offered the same advice: Stop rinsing your dishes first. Palmer-Smith said the food sensor should start working again pretty quickly. But if you don’t notice a difference after several cycles, Gilbert said, the sensor likely has to be replaced.  

As the experts explained, after the wash cycle, some food may end up in a built-in food trap. This leads to another common mistake people often make: never cleaning their dishwasher. “The dishwasher should be cleaned about once a month,” Palmer-Smith said. This includes emptying out the food trap and giving it a wipe-down with your favourite kitchen cleaning product. It only takes a few minutes, but it’s key for keeping your dishwasher working properly long-term.

So there you have it: A 100% valid reason to skip a step in your post-meal cleanup routine. Palmer-Smith summed the lesson up this way: “People need to let the dishwasher do what it’s supposed to do, which is wash dishes.” Now if only there were a way to make unloading faster …