The smelly secret in the kitchen: You put dirty dishes into the dishwasher, press a button, and assume that at the end of the program everything comes out clean. But if you have not cleaned the filter at the bottom of the dishwasher, it is possible that some of the food residue from yesterday, last week, and perhaps even a month ago, is still there. It not only causes an unpleasant odor, but could also impair water flow, leave dirt on the dishes, and create a humid and grease–rich environment where microorganisms thrive.
In recent years, the dishwasher has become one of the most convenient electrical appliances in the home. It saves water, time, and hassle, and in hot programs, it also helps reduce the bacterial load on dishes. But precisely because of its clean image, many people forget a basic detail: The dishwasher does not clean itself completely. It washes dishes, but some of the food residue does not magically disappear. It reaches the filter at the bottom, the crevices, the door gaskets, the spray arms, and sometimes also the pump area.
The problem usually starts at the filter. In many modern dishwashers, especially in quiet and economical models, there is a manual filter designed to trap food residue, grains, grease, vegetable pieces, seeds, and crumbs. Its role is important: To prevent dirt from entering the pump and returning to the dishes. But when the filter is not removed and rinsed regularly, it turns from a defense system into the source of the problem. Instead of stopping the dirt, it begins to accumulate it.
At this stage, the first sign appears: A bad smell when opening the door. Sometimes it is the smell of standing water, sometimes a sour smell, and occasionally a smell reminiscent of a wet trash can. Many try to solve this by using a dishwasher cleaning liquid once a month, and this can certainly help remove grease and limescale. But a cleaning liquid is not always capable of physically removing a piece of food stuck in or under the filter mesh. Just as a shower will not clear a clog in the sink if a lump of dirt remains in the strainer, the cleaning agent in the dishwasher will also not always succeed in dealing with a layer of organic dirt accumulated for weeks.
From a health perspective, it is important to be precise: A dirty dishwasher does not mean that every meal becomes an immediate danger. Most healthy people will not get sick just because the dishwasher filter was not cleaned on time. However, a kitchen is a place where food safety depends on many small actions, and a neglected dishwasher has an undesirable combination of humidity, heat, food residue, and grease. These are conditions that can allow bacteria, fungi, and mold to exist in certain areas of the appliance, mainly in the gaskets and in areas that are not rinsed well in each cycle.
Studies that examined domestic dishwashers found that dishwashers are not a sterile environment. Bacteria and fungi can be found, among other places, in the door gaskets, water, plumbing, and internal parts of the appliance. This does not mean one should panic about the dishwasher, but rather treat it like any wet appliance in the kitchen: Clean, ventilate, and maintain. When it comes to families with babies, the elderly, people with a weakened immune system, or oncology patients, this meticulousness is even more important.
The second mistake is ignoring the door gaskets. Most people clean the inside of the dishwasher only when it already stinks, but precisely the rubber strips around the door are a problematic area. The water and soap do not always reach them with sufficient force, especially the lower part of the door and the edges. A sticky layer of grease, dirt, and mold can accumulate there. It is enough to pass a damp cloth along the seal to understand how much dirt is hidden there, even in a dishwasher that looks sparkling from the outside.
The third mistake is the almost regular use of a short or economical program. Such programs are important for saving electricity and water, but they do not always remove stubborn grease with the same efficiency as a hot and intensive program. When using only short or cooler programs over time, grease from food may remain on the walls, plumbing, filter, and spray arms. The result is not only a bad smell, but also dishes that come out less clean, glasses with a greasy feel, and cutlery that looks as if it only underwent a partial rinse.
The fourth mistake is closing the door hermetically after each operation. A dishwasher that has finished working remains hot and humid. If it is closed completely immediately after clearing the dishes, the moisture is trapped inside. A humid and closed environment is exactly what mold and bad odors love. Therefore, it is advisable to leave the door slightly open after the operation ends, to allow drying and ventilation. In advanced models, there is sometimes an automatic opening of the door at the end of the program, and it is worth ensuring that this option is active.
And there is another surprising mistake: Excessive rinsing of dishes before the dishwasher. Many are convinced that dishes must be put into the dishwasher almost clean, but in modern dishwashers, the accepted recommendation is to clear solid food residue into the trash, not to rinse every plate under the tap. Excessive rinsing wastes water, and sometimes also disrupts the operation of sensors or reduces the effectiveness of enzymatic detergents, which are designed to break down fats and proteins. Dishes should not enter with lumps of food, but they also do not need to undergo a full rinse before the dishwasher.
So what do we do tonight, before the smell returns again? Start with the simplest action: Remove the lower basket, turn the filter at the bottom, and pull it out carefully. In most dishwashers, it consists of a cylindrical filter and a flat mesh. Rinse it well under running water, with a little dish soap and a soft brush or an old toothbrush. If you see a greasy layer, crumbs, seeds, or gray dirt, that was probably the source of the smell.
The next step is cleaning the door gaskets. Take a damp cloth with a little soap, or a cleaning agent suitable for kitchen appliances, and pass it along all the seals, especially at the lower part of the door and in the corners. If there is visible mold or a black layer, do not ignore it. Clean gently, dry well, and in case of recurring mold or damaged rubber, it is worth checking if the seal needs replacement.
After the gaskets come the spray arms. These are the "sprinklers" that rotate inside the dishwasher and flow water to the dishes. When their small holes get clogged with food particles or limescale, the water does not reach everywhere. The result: Entire areas in the dishwasher remain dirtier. In most models, the lower arm can be pulled out, and the upper one can be removed by a simple unscrewing. Rinse under running water, and if necessary, open clogged holes gently with a toothpick.
Only after manual cleaning is it advisable to run a hot program. Once every two weeks, or at least once a month in a dishwasher under light use, it is recommended to run a hot intensive program, according to the manufacturer's instructions. If the dishwasher is used daily, you cook a lot, or you put in dishes with a lot of grease, it is advisable to clean the filter more frequently, sometimes once a week or once every two weeks. In a household with normal use, cleaning every two weeks to a month is a reasonable target, but the smell is the clearest indicator: If the dishwasher stinks, wait less.
The important message is not to fear the dishwasher, but to stop treating it as a magic device. A properly functioning, clean, and maintained dishwasher is an excellent tool for maintaining dish hygiene. Health authorities note that in situations where better sanitation is required, for example for baby bottles or during water contamination events, a hot program, heat drying, or a sanitation program can help reduce bacteria. But even the hottest program does not exempt from cleaning the filter, the gaskets, and the areas where physical dirt simply remains stuck.
Therefore, the rule is simple: Clear solid residues into the trash, do not rinse every plate until it sparkles, clean the filter regularly, ventilate the dishwasher after operation, wipe gaskets, check spray arms, and run a hot program from time to time. If after all this there is still a bad smell, dirty dishes, standing water, or signs of recurring mold, this is no longer just a cleaning problem, but a reason to check for a malfunction in the drainage, pump, plumbing, or sealing.