Do You Really Need to Pre-Rinse Your Dishes?

There’s something about a dishwasher that stirs up controversies and conundrums, which is intriguing for such an unassuming kitchen appliance. You’ve probably been privy to a dishwasher-related squabble, either in real life or online, from the best way to load the dishwasher to the proper place to put detergent pods. 

A perennial appliance question seems to be: Should you pre-rinse dishes before loading them into the dishwasher? And if you do pre-rinse, are you wasting water and doing too much of the machine’s job? If you don’t rinse them, will the machine work hard enough to remove all the grime?

We talked to cleaning expert Sabrina Fierman and pros at two of the nation’s biggest home appliance companies to get the final word on the pre-rinse enigma.

Should you pre-rinse your dishes before loading them into the dishwasher?

The bottom line: You should scrape excess food from plates and bowls versus rinsing. According to Fierman and experts at GE Appliances and LG, dishwashers sold within the last 10 to 15 years feature sensors that detect the most heavily soiled areas and “automatically adjust the cycle to reduce or increase water usage, target cycle temperature, and cycle time, depending on the amount of soil on the dishes,” says Jill Condra, product marketing senior manager for Dishwasher at GE Appliances. 

In other words, placing spotless, pre-rinsed dishes in your machine will signal that it can run a lighter wash. Scraping versus rinsing saves water and removes most of the stuck-on food, but leaves enough residue to ensure a deep clean from your machine.

Aside from saving time and energy, skipping a manual pre-rinse saves water. Energy Star-certified dishwashers use as little as three gallons per load, while the average kitchen faucet flows at 2.2 gallons per minute. If you hand wash or rinse dishes for five or 10 minutes, you’re using three to six times the amount of water needed for one dishwasher cycle. (If you have an older model—say one built before 1994—it may use more than 10 gallons per load, according to CNET.)

What if you have an older dishwasher?

“Pre-rinsing dishes is necessary for older model dishwashers (early 2000s and before),” Fierman says, because they lack the sensor technology of modern machines. 

If you have a new dishwasher, but are having issues with the scrape vs. pre-rinse method

If a newer dishwasher is turning out not-so-clean dishes after the scrape method, it’s usually due to one of these culprits:

• Improperly loading the dishwasher, like overloading with too many dishes, blocking the spray arm, or not putting the dirtiest dishes on the bottom rack. Here’s our complete guide to loading your dishwasher the right way. 
• A clogged filter or drain basket. No matter what year your machine was made or if you’re a scraping-versus-rinsing convert, it’s best practice to periodically clean your dishwasher’s filter. “If users fail to do this, it can impact the wash performance, and some users will then have to switch to more energy intensive cycles to overcome the impact of not cleaning the filter,” Condra says.
• “In some instances, a hot water heater may be set to a lower temperature than is ideal for the dishwasher,” Fierman says. “Discuss this with a plumber or electrician.”
• To ensure an optimum clean, use a detergent recommended in your machine’s manual. Most dishwashers will work well with pods or powder, but some manufacturers have specific recommendations.

If you have a newer-model dishwasher, this is your permission slip to go forth and scrape, load, and go. No more hovering over the sink for longer than you need.