Dishwasher leaving residue on dishes? Your dishwasher should reveal sparkling clean dishes and crystal clear glassware every time you open it after a cleaning cycle. If you notice whitish residue (sometimes brown) or film on your dishes and glassware, it could be salt or limescale.
This means you have to wash your supposedly clean dishes and glassware a second time before use.
The fact is that these ‘Residues’ occur due to a number of different reasons, but the most probable cause of your dishwasher leaving residue on dishes is due to the build-up of grease in your appliance, which occurs due to improper cleaning of your dishwasher on a regular cycle of 6-12 weeks to aid removal of excess food particles stuck inside it.
Fortunately, there are several methods to solve the residue problem so your dishes turn out clean and sparkling every time you run your dishwasher.
Common types of dishwasher residue
Here’s a list of the most common types of dishwasher residues and how to tackle them
- Soap residue
- Hard water (white) residue
- Brown residue
- Gritty residue
Dishwasher leaving residue on dishes: how to fix
Below are the various ways you can stop your dishwasher from leaving residue on dishes:
1. Soap Residue
Soap (dish washing detergents) can leave a residue on your dishes. Paradise Appliance even claims that the residue could be due to using a subpar detergent. This can be prevented by doing the following:
To prevent soap residue, do the following:
a. Avoid the use of excess detergent in your dishwasher.
The rinse cycle can’t remove or dissolve the excess detergent totally, resulting in a residual build-up on the inside of the dishwasher, which can end up on your dishes. It’s recommended that you experiment with dishes you aren’t using right away until you find the right amount that isn’t leaving a residue or soapy taste in them.
b. Employ the use of different high-quality detergents.
Dishwasher detergents are available as gels, powders, tablets, or pods, with each working differently in dishwashers:
- Gels are usually the cheapest, but they don’t clean as well as the other types of detergents. However, they’re more suitable for washing delicate dishes and glasses because they’re less abrasive.
- Powders are best suited for washing burnt-in stains on pots and pans, although they’re too abrasive for washing glassware and tableware.
- Tablets or pods are concentrated gel packs or dishwashing powder containing rinse aids that help remove soap residues by pre-washing dishes.
c. Use less water
It’s been noted that the lesser the water on the dishes, the lesser the soap residue when drying. Using a rinse aid makes the rinse cycle much more efficient by helping the water run ‘off’ the dishes more easily. Also, check the dispenser to make sure there’s enough for each wash.
d. Always begin the dishwashing cycle with the hottest water possible
Run the water at your kitchen faucet until it’s at the right temperature (between 120 and 150°F) to dissolve and properly use the detergent so no white residue is left behind, and then start the dishwasher.
e. Check the water pressure
Check the water pressure in the plumbing that runs to the dishwasher to make sure it’s not running low because there won’t be enough pressure to rinse the soap off the dishes if the water pressure is low.
Causes of low water pressure in the dishwasher include:
- A clog or kink in the water supply hose.
- A blocked water inlet valve screen.
- An excessively small water line that’s restricting the flow of water into the dishwasher. The water line should be 3/8-inch o.d. (outside diameter) copper or 1/2-inch o.d. plastic.
- A leak in the plumbing line that supplies water to the dishwasher.
f. Reduce the load
You can experiment by running a smaller load to see if improper or overloading is the cause of the soap residue because water needs to reach all the dishes for a proper rinse.
g. Run the cycle appropriately for the number of dishes being washed
Don’t use a quick wash cycle for a large number of dishes.
h. Clean the spray arms
Make sure the spray arms are clean and free of debris, and nothing is blocking them.
i. Run vinegar cycles
It’s advisable to run vinegar cycles through the dishwasher to break up and remove soap residue:
- For the first cycle, fill a large dishwasher-safe bowl with vinegar and place it on the top rack. Then run the cycle on the heaviest setting with the hottest water.
- For the second cycle, add 2 cups of vinegar to the bottom of the dishwasher, and begin the cycle on a low setting with the hottest water. Stop half-way through the wash cycle for 20 minutes, and then continue again.
- Repeat this procedure to refresh your machine as needed.
Hard Water (White) Residue
Whitish mineral deposits found on your dishes after a wash cycle are commonly referred to as Hard Water residue or deposits. Hard water residue can also build up inside your dishwasher, adding further mineral residue to dishes at every wash cycle.
To prevent hard water residue, do the following:
- Always run regular vinegar cycles to help prevent mineral deposits from building up inside the dishwasher.
- Use a rinse aid and citric acid for each wash cycle to remove any hard water residue from dishes and the dishwasher. You can do this by adding a teaspoon of citric acid to your detergent for each load or putting 3 to 4 tablespoons of citric acid in the detergent dispenser, and then running an empty load at normal ‘level’ to clean out any hard water residues.
- Using a sodium-based detergent helps to soften the water.
- A more permanent solution for removing hard water deposits is the installation of a soft water system for the house. Soft water is more effective for cleaning and lathers more easily than hard water.
- Many people make the mistake of adding more dishwasher detergent to get a better wash with hard water, but unfortunately, the soap doesn’t completely rinse off, resulting in more residue.
3. Brown Residue
The reasons mostly responsible for brown residues in the dishwasher are outlined below:
- Lack of regular cleaning cycles can result in your dishwasher leaving a brown residue on dishes.
- Manganese and iron deposits present in the water can give it a yellowish or brownish color and these deposits can remain after the water has evaporated. It’s rather unusual to find these residues on your dishes but very normal to find them on the inside of the dishwasher.
- Mold is another culprit responsible for this. Infrequent use of the dishwater and keeping the door closed between uses allows mold to grow on the door gasket, rotor, and other parts that aren’t completely smooth. Also because the moist temperature inside a dishwasher promotes the growth of mold, making it difficult to wash away once it’s established.
How to remove Brown Residue?
This can be removed by:
- Scrubbing the inside of the dishwasher
- Treating it with a disinfectant such as vinegar, citric acid, or baking soda,
- And manually clean any part that you can remove and wash in the sink.
4. Gritty Residue
There are two possible reasons why the residual film left behind by your dishwasher feels gritty.
The first is a temporary problem due to undissolved detergents, which is most common with powdered detergent and dry detergents.
Simply hand washing the dishes will remove the gritty film. You can also prevent future problems by making the water in your dishwasher hotter before a wash cycle.
The second is a permanent problem known as ‘Etching’.
Etching occurs when tiny bits of soap powder scratch the dishes. Those little divots or bumps you feel when you run your fingernail down a glassware, are permanent scratches resulting from Etching.
Switching to a liquid detergent takes care of the problem, but it won’t undo any damage that’s already occurred.
How often should I clean a Dishwasher?
Regular cleaning of your dishwasher kills bacteria and prevents residual buildup on your dishes.
Ideally, you should clean your dishwasher at least every 2 months or once a month if you use it more than twice a day to ensure your dishes are properly cleaned.
Deep or soft cleaning are the 2 different methods you can employ to clean your dishwasher.
Follow these steps to soft clean your dishwasher:
- Fill a measuring cup or dishwasher-safe glass bowl with white vinegar
- Place the vinegar dish on the bottom rack
- Run the dishwasher on a full cycle
- Use a clean rag to wipe out the inside of the dishwasher when the cycle is completed
- Try running another wash cycle if there is still a strong smell of vinegar noticeable. This should help to flush out the remaining vinegar. You can also consider adding a tablespoon or two of baking soda to help absorb the scent and run another cycle.
Soft cleaning is recommended every 2 months to prevent the build-up of debris and grease. Or, when you begin to notice white residue or grease on your dishes.
Follow these steps to deep clean your dishwasher:
- Spray a degreasing agent inside the dishwasher and then wipe clean
- Run the vinegar through a rinse cycle
- Unplug the dishwasher when the cycle is completed
- Remove the bottom and top racks of the machine
- Soak them in hot water mixed with vinegar
- Remove the dishwasher fan (follow your manufacturer’s directions in the dishwasher’s user manual)
- Use a thin wire to clean out the spray holes
- Rinse thoroughly
- Return the fan and racks to the dishwasher
- Plug the machine back in
- Run a cycle without soap to rinse everything
Deep cleaning is advisable at least twice a year to prevent any residue or grease from accumulating in the crevices of the dishwasher.
How to properly load a Dishwasher
Here’s how to properly load a dishwasher to avoid residues (always check your dishwasher’s user manual for any special loading instructions):
Upper rack: concave-shaped items such as glasses, mugs, bowls, utensils, silverware, and dishwasher-safe plastics to prevent warping.
- Angle bowls facing the center with spaces in-between them to prevent breakage, and also to allow water and soap to reach them.
- Glasses and mugs must be placed between the tines and not on them.
- Place large silverware and utensils horizontally.
- Utensils must be properly secured with long handles so they don’t fall through and stop the spray arm from rotating.
Lower rack: platters, plates, larger utensils, and cooking utensils.
- Arrange plates and platters vertically.
- Stagger small and large pieces so water and detergent can reach the top rack.
- Place oversized items such as dishwasher-safe cutting boards, along the perimeter.
Utensils rack: All types of utensils can be put here.
- Make sure you load forks and spoons with their handles facing down.
- Always load knives with the handles facing up.
- Mix up cutlery items to prevent them from nesting together, resulting in incomplete washing and rinsing.
- If using a utensil rack: lay each item flat and don’t overlap them to ensure that each item can be cleaned properly.
What can you do to prevent any future residue in a Dishwasher?
Properly scraping your dishes before putting them in the dishwasher is the best way to prevent grease build-up as large pieces of food can become lodged in the dishwasher drain causing it to get clogged up.
The more debris in the dishwasher drain, the harder it is for the grease and food to exit properly.
Most people make the mistake of cleaning their dishes before putting them in the dishwasher. This would be perfect if you were using a sanitizer, but there’s no need to clean your dishes for your dishwasher because dishwashing detergents have active enzymes which work in tandem with hot water to remove the food from the dishes. If you clean the dishes before putting them in the dishwasher, you prevent the enzymes from latching onto the food and cleaning it properly.
However, this does not mean you should leave large chunks of food on the dishes. Make sure you scrape the dishes thoroughly but do not wash them before putting them in the dishwasher.
Consistent cleaning as discussed earlier will also prevent residue build-up. You should clean out the drain filter at least every three months; this can be done by shutting off your dishwasher and pulling it out of the drain, rinsing it thoroughly with hot, soapy water, and putting it back once you see it’s free of debris and grease (residue).