How to Clean Baked-On Grease With Washing Soda (Denise’s “Super Soap”)

Step by step

1. 1

   Get your washing soda

   Washing soda is sold in the laundry aisle, usually as Arm & Hammer Super Washing Soda. It is not the same thing as baking soda. If you cannot find it, you can make it from baking soda in your oven (see “Making washing soda from baking soda” below).

2. 2

   Make the Super Soap spray

   Put on your gloves. In a spray bottle, mix:

   • 2 cups warm water
   • 1/2 cup washing soda
   • 1 to 2 tablespoons dish soap

   Close it, swirl gently until the powder dissolves, and label the bottle “Super Soap: washing soda, gloves on.”

   This is a strong mix, about 8 times stronger than the maker’s everyday cleaning solution, so it is for real grease and not for wiping counters. If you want the gentle everyday version, use the maker’s ratio instead: 1/2 cup washing soda in a gallon of warm water.

   What it looks like: cloudy at first, then mostly clear once it dissolves. A few grains on the bottom are fine; swirl again before each use.

3. 3

   Spray, wait, wipe

   Spray the greasy spot until it is wet, wait 5 minutes, then wipe with a non-scratch sponge. Rinse the surface well with plain water and dry it.

   What it looks like when it is working: sticky grease turns slick and slides off under the sponge, and the sponge comes away yellow or brown. If the spot is a hard, shiny brown layer that does not move at all, that is baked-on grease, and Step 4 is for you.

   

2. 4

   Paste for the baked-on brown layer

   In a small bowl (not aluminum), stir 2 parts washing soda to 1 part water. For one pan, that is 1/2 cup washing soda and 1/4 cup water, plus a drop of dish soap. It should look like thick, wet sand. Spread it over the brown spots in a layer you cannot see through.

   Optional swap: you can use 3% drugstore hydrogen peroxide in place of the water. Together, washing soda and peroxide are close to what oxygen bleach powder makes in water. We could not find any test showing it beats plain water on grease, so water is perfectly fine.

   If you do use peroxide, mix it right before you use it and never put a lid on it.

   
3. 5

   Wait 30 minutes

   Leave the paste alone for 30 minutes. That is the maker’s stand time for pots and pans, and the wait is what does the work.

4. 6

   Scrub, rinse, wash

   Scrub with a non-scratch sponge, rinse the pan thoroughly with plain water, then wash it with dish soap like normal.

   What it looks like when it is working: the brown layer softens and starts coming away in flakes or smears as you scrub. If one spot will not budge, put on a second coat of paste and give it another 30 minutes. Very old, thick buildup often takes two rounds.

Making washing soda from baking soda

Heat changes baking soda (sodium bicarbonate) into washing soda (sodium carbonate), giving off water and carbon dioxide as it goes.

1. Spread baking soda in a thin, even layer in a glass or stainless baking dish (not aluminum).
2. Bake at 350°F for 30 minutes to an hour, and stir it once halfway.
3. Check that it worked by weighing it. Washing soda weighs about a third less than the baking soda you started with. Weigh before and after: 16 ounces of baking soda should come out at about 10 ounces. If it is still heavier than that, give it more time.
4. Let it cool all the way before you touch it.
5. Store it in a container with a tight lid and label it clearly: “WASHING SODA. NOT FOR COOKING.” It looks just like baking soda, and you do not want anybody stirring it into biscuits.

Is it cheaper to make it? Not really. On November 6, 2026 at Target.com, a 5 lb bag of baking soda was $4.99, and it makes about 50 ounces of washing soda (about 10 cents an ounce). A 55 oz box of washing soda was $5.49, which is also about 10 cents an ounce.

So making it is for when your store does not carry the box. It is not a way to save money.

When it will not work, and what to do instead

If one of these sounds like your pan, here is what to do instead.

• Your pan is aluminum or nonstick. Do not use this at all. Soak in hot water with dish soap and use a non-scratch sponge.
• The brown layer did not move after two rounds. On old pans, some of that darkening is baked in for good. If it is smooth and not flaking, it is a looks problem, not a cooking problem.
• You mixed it with vinegar. It makes sense that two cleaners would beat one, and the fizz sure looks busy. But vinegar is an acid and washing soda is a base, so they cancel each other out. Rinse and start over with plain washing soda.

Why it works

Dish soap is wonderful on fresh grease. One end of each soap molecule grabs onto oil and the other end grabs onto water, so the grease rinses away.

But grease that has been through the oven a few times is not really grease anymore. Heat links the oil together into a hard, heavy layer, the same way a cast iron pan gets its seasoning. Soap alone just slides across the top of that.

Washing soda is a fairly strong alkali (the opposite of an acid, like vinegar). An alkali can turn some of that hard fat into soap and loosen the rest. Now your dish soap has something to grab. That is the whole trick: you are not replacing your dish soap, you are giving it backup.

And honey, let me save you some fizz. Baking soda and vinegar bubble up so pretty that it feels like something is happening. What is really happening is that they use each other up, and you are left with mostly water, a little salt and some gas. It is a fine science fair volcano, but it is not a degreaser.