We are reader-supported. When you buy through links on our site, we may earn a commission. Learn more about our review process.

Nerdy Science in the Kitchen

Why is My KitchenAid Mixer Turning Food Gray?



KitchenAid stainless steel mixing bowl with white paddle and cookie mixture
Your KitchenAid mixer makes delicious treats for your familyKitchenAid mixers have been in kitchens for decades, used for many purposes: pulling chicken and pork, mixing meatballs, and blending sweet and savory ingredients. Most often, however, these wonderful gadgets are used to mix dough and batter to make delicious sweet treats.

Unfortunately, sometimes the mixer and its components leave behind a sticky, gray or slightly black residue in these very same foods.

Why Your KitchenAid Mixer Is Leaving Gray Streaks in Your Food

Knowing why this happens is the first step in combating it. Keep reading to discover the common reasons this residue is appearing in your prepared foods and to figure out how to stop this from happening ever again!

Reason One: Your KitchenAid Mixer Has Soap On It From the Last Wash

The most common culprit of this gray residue is your dishwashing soap or dishwasher detergent. The light black streaks in your mixer bowl’s contents are caused by a chemical reaction between the surfactant (or soap) in your dishwashing liquid and your mixing bowl and/or mixer attachments.

When you use a detergent that has alkalines in it, as many soaps and detergents do, on dishes that contain an acid like fruit juice or tomato sauce, the two will react with one another in an area of contact called an ionic bond.

This causes the ionic bond to form and break at random intervals as long as there is alkaline and acid being introduced. This can leave behind a sticky residue that is very difficult to wash off of your KitchenAid mixer attachments and out of your bowl.

Solution: How to Avoid KitchenAid Mixer Soap Residue

There are several things you can do to avoid having your KitchenAid mixer leave a gray residue in your food and in the mixing bowl. The first thing you can do is use a detergent that contains no alkalines whatsoever in it. Either a homemade dishwashing liquid (using vinegar and salt) or a natural dishwashing liquid will work well with your KitchenAid mixer without leaving any residue behind.

Also helpful is washing your attachments and mixing bowl by hand with dishwashing soap and then rubbing down all their surfaces with cooking oil and then lemon juice to make sure all the soap that causes this unsightly gray residue is removed before you use your mixer again.

If you prefer to use the dishwasher, you can also combat the problem by using a rinse agent like Jet Dry or just plain white vinegar in loads that contain KitchenAid components and mixing bowls. The rinse agent will eliminate the ionic bond from forming by spreading the alkalines across the surface of your dishes, preventing them from sticking together in one place and breaking apart randomly.

Problem: The KitchenAid Mixer Is Leaking Lubricant Into Your Bowl

Although this is less likely, it may be that the head of your KitchenAid mixer is leaking a few drops of oil into your mixing bowl. Do you find a few drops of oil streaking the bottom of your mixing bowl? Do you see a bit of oil oozing down the beater’s shaft? Have you seen oil leaking out of the appliance after it has been laid on its side for shipping or storage? If so, this is your culprit.

Since the makers of KitchenAid mixers put enough lubricant in their machines to last a lifetime, sometimes the oil will separate. This happens often in the warmer months and in machines that are not used very often. This tiny amount of oil that collects in your bowl or drips down from the head of the gadget will mix with your food, causing that annoying gray residue that no good cook wants.

Solution: How to Prevent Oil from Your KitchenAid Mixer Leaking Into Your Bowl

If you use your KitchenAid mixer only once in a while, occasionally take it out of storage or from the corner of your counter where you keep it and turn the mixer on for a few minutes without any ingredients in the bowl. This will keep the oil from separating as much and prevent the drips.

If you want to use the mixer, turn it on with no ingredients in the bowl and let it run for two minutes or so at speed 10, then wipe away any oil on the head or beaters or in the bowl.

If none of this works, you may want to take your KitchenAid mixer to a local service facility and request that the old grease be removed and replaced with a new lubricant. At the same time, they will also replace the gasket, all of which will solve your problem.

Problem: The KitchenAid Mixer’s Aluminum Paddle Is Rubbing On Your Mixing Bowl

If you have checked to make sure that no lubricant is dripping from the head of your KitchenAid mixer, you have changed your dishwashing detergent to one that contains no alkalines, you have carefully rinsed your components and bowl with vinegar, and you still find a dark grayish residue in your foods, the final problem may be something else.

The problem may be with the paddle itself. Is it an anodized aluminum paddle? If so, your beater is probably rubbing against the bottom of your bowl as it mixes your food, as the aluminum from this paddle will rub off during the mixing process.

Solution: How to Keep Your KitchenAid Mixer’s Paddle from Turning Food Gray

This one’s a very easy fix! Either adjust the height of your mixing bowl to keep your paddle from making contact with the bowl itself, or simply purchase a new paddle or side-sweep beater that is not made of anodized aluminum.

There are paddles available that are silver-colored but are not coated with aluminum; they also sell paddles and beaters that are coated in a white polyester material. Voila! Problem solved.

Coated Flat Beater for KitchenAid Mixer on Amazon

A Final Note: Is the Food Tinted Gray from My KitchenAid Mixer Safe to Eat?

Although the gray residue left behind by your KitchenAid mixer may not look very appetizing, it is completely safe to eat.

The minuscule amount of soap left on your KitchenAid attachments and mixing bowl will not harm you. The lubricant that drips down into the bowl is food-grade oil and, although unsightly, is completely edible. Even the microscopic amount of metal deposited in your food from an aluminum beater cannot hurt you.

The residue is not harmful in any way, and it will not be absorbed into the food you are preparing. There is no need to worry about eating anything that has been left behind by your KitchenAid mixer. And use these tips to ensure that next time, your food will be perfect in every way.

Additional Resources:

Stand Mixer Magic” (CC BY 2.0) by Rex Roof