Remnants of food, grease, undissolved detergent, and water minerals build up on your dishwater filter (and the machine’s interior walls) over time, resulting in a foul odor and unpleasant look. But what’s more alarming is that, if left uncleaned, all of this build-up can actually leave spots or a grimy film on your glasses, dishes, and silverware, so they won’t actually be clean after a wash. Also, if all the gunk and goo really piles up, your dishwasher filter and pump can become seriously damaged, which requires expensive repairs (via Good Housekeeping).
You might be appalled by this news, but dishwasher filters are actually meant to catch and store all these little bits and pieces. They prevent the debris from redepositing onto clean dishes and clogging up the drain. According to Larry Ciufo, the dishwasher expert for Consumer Reports, only dishwashers that are about 10 years old or older probably have a self-cleaning filter. Apparently, over the past decade, manufacturers have switched to manually-cleaned filters to offer quieter dishwashers, which are more preferred among consumers. Self-cleaning filters are often paired with a noisy grinder.