Scientist Explains Why You Shouldn’t Rinse Your Dishes Before Putting Them in the Dishwasher

Your nightly routine probably consists of doing the dishes by hand or loading them into the dishwasher. Before popping them into your machine, it’s likely you’re taking the extra step of rinsing off any food debris.

It’s almost automatic, especially when your little one leaves a pile of mashed peas on his plate or the dishes are caked with lasagna residue. But experts say you can stop. What experts and why, you say? Dishwashing and cleaning experts who are trying to save you time.

Small household squabbles can arise over the who’s loading the dishwasher properly. Utensils up or down? Plates grouped by size and shape? To rinse or not to rinse? Pet peeves, personal preferences, and manufacturer’s instructions (who reads those?) battle it out in kitchens each night or the next morning when the washer is opened.

When it comes to pre-rinsing, you can leave things alone. That doesn’t mean you should leave chunks of food on the plate. By all means, scrape it off. But your appliance maker and dish detergent manufacturer agree that a little food is okay.

This is because technology has improved so much that machines can handle certain amounts of food particles and crumbs. Dishwashers have sensors that can recognize the dirt level for a load. The machine will adjust itself and go longer or shorter, depending on what it’s picking up on its sensors.

Detergent manufacturers also point out that the enzymes in their products help to break down food debris. In interview with Today, a scientist who works for Procter & Gamble explained how the process works:

“The water in the pre-wash will remove any loose soils the same way they would be removed with water alone by rinsing in the sink — think things like ketchup or loose crumbs.

The machine will then recognize that there is food present and will run a more thorough cleaning cycle. If you pull a helicopter cleaner and you rinse all of your dishes except for one casserole dish with some baked on cheese or one morning bowl of stuck-on oatmeal, nothing will come off in the pre-wash, telling your dishwasher that there’s no food present, and it will run a shorter cycle, leading to a less thorough clean and potentially some cheese or oatmeal left on the dish.”

It’s noted that most machines sold in the last five years or high-end models are the most capable of dissolving food grime. However, it is still advised to clean your dishwasher periodically to keep it in good shape. Hint: vinegar and baking soda are your friends.

Now that we know skipping the pre-rinse is a smart option, we can go back to arguing over the best way to load the dishwasher. If you’re still a little skeptical, bypass your faucet and run an experimental cycle to see how it goes. You might enjoy having to do less work.

Are you a dedicated dish pre-rinser? Will you let your dishwasher handle the dirty work now? Have you already eliminated the pre-rinse step?