The very name "dishwasher" implies that the appliance is self-cleaning, which it is for the most part. Every now and then, however, the trusty and beloved kitchen accessory needs a hand in order to keep functioning in peak condition. This is especially because the warm, moist environment and alkaline pH values inherent in the machines make them prime breeding grounds for some pretty nasty fungi and bacteria. In fact, a small study published in the journal Fungal Biology found that 62 percent of dishwashers tested contained fungi that can be problematic for humans. Yet another paper, published in the journal Applied and Environmental Microbiology, found significant bacteria and fungi present in dishwashers, which they describe as "diverse habitats for microorganisms to adapt and flourish." Fortunately, it really isn't difficult or time-consuming to keep your dishwasher humming along cleanly, provided you follow a few steps:
1. Wipe It Down From Time to Time
Most dishes go in dripping at least some sauce or other food-related liquid. Although it's not necessary to totally pre-rinse dishes before loading them, the foodstuffs on dishes can build up over time and leave residue in the dishwasher. To fix, simply use a damp cloth with a very small amount of liquid dish detergent to wipe down the rubber seals and the door interior. This will keep grime and other nastiness from building up to epic levels.
Also, every dishwasher comes equipped with a dishwasher spray arm, which should be removed and wiped down with a damp towel about every six months or so. The owner's manual contains easy instructions on specific steps, but a common recommendation is to dislodge any potentially problematic blockages in the spray holes of the spray arm using a simple toothpick.
2. Clean the Filter
Don't feel bad if you didn't know that your dishwasher has a filter – most people don't. Typically located at the bottom center of the dishwasher, the two-part device serves a couple of purposes. The upper filter is designed to keep chunks of food and other foreign particles from invading the ever-important pump, while the lower filter prevents food bits from going back out onto the clean dishes.
Indications that the filters need cleaning include any obvious grossness on the upper filter, or dishes that keep coming out soiled or "gritty" despite running through a full cycle. As a general rule of thumb, the more you use your dishwasher and the less you rinse/scrape food, the more you need to clean out the filter. If you rinse and scrape your dishes before putting them in the dishwasher, you only need to clean the filter once or twice a year. If you don't, more like once per month.
To remove the filter, check your dishwasher's manual for easy steps. Then once it's out, just hold it under running water until all or most of the offending soils are washed off. Reinstall according to manufacturer directions. It's a lot easier than it sounds, we promise.
3. Run a Cleaning Rinse
If your local water is hard, mineral deposits can build up over time, so many manufacturers recommend running a dishwasher-specific cleaning solution about every month or so (a bunch of products are commercially available but 2 cups of white vinegar can work as well). This can also tackle soap scum. Be sure to follow the directions on the bottle and run it in an empty machine, typically on highest heat and the heaviest setting available.