Make Washing Soda/Soda Ash from Baking Soda (for fabric scouring)
Washing soda, also known as soda ash, is used in our household to scour fabrics in preparation for waxing and indigo dying, to clean laundry, the kitchen and the bathroom, and to remove stains from stainless steel cookware. It is a very versatile natural ingredient but is not as easily available as baking soda, so we will show you how we make washing soda from baking soda. Enjoy this easy tutorial!
Video tutorial
You can also watch this video on YouTube.
The science!
Chemically speaking:
Washing soda (sodium carbonate) = baking soda (sodium bicarbonate) - carbon dioxide - water
To get rid of the excess water and carbon dioxide in this equation, you simply have to apply heat to baking soda.
Why would you want to use washing soda instead of baking soda? Washing soda is more alkaline than baking soda. It has a pH of 11 whereas baking soda has a pH of 8.3. Its basic nature makes it more powerful in its cleansing abilities. Baking soda may be the more popular natural cleaning agent, but if you ever come across some tough stains tougher than it can handle, we recommend trying its big sister washing soda!
Differences between baking soda and washing soda
| Baking Soda | Washing Soda/Soda Ash | |
|---|---|---|
| Chemical name | Sodium bicarbonate | Sodium carbonate |
| pH | 8.3 | 11 |
| Density | 2.20g/cm3 | 2.54g/cm3 |
| Safety | Mild irritant | Irritant |
| Cleaning power | Mild | Strong |
| Appearance | Clumpy | Smooth powder |
| Edibility | Widely used in baking and cooking | Used in selective cases (do your research) |
Uses for washing soda
- Clean laundry and tough stains on fabric
- Clean stains on bathroom and kitchen surfaces
- Remove stains and rust on stainless steel (read more below!)
- Scour cellulose fabric such as cotton canvas and linen to prepare for waxing and dying (i.e. remove grease and dirt accumulated in the factory)
- Soften hard water
- Food (do your own research!): Used to make kansui (鹼水) for making ramen, moon cakes, Chinese buns, and other wheat-based foods; to give pretzels its dark brown colour
How to make washing soda
Time needed: 10 to 30+ minutes depending on batch size
- Prepare a dry stainless steel cooking pot.
- Pour desired amount of baking soda into pot.
- Turn heat on medium to high.
- Stir regularly and break up any chunks.
- As the baking soda heats and water evaporates away, it will feel lighter and more airy to stir. Clumps present will start to disintegrate. You may see steam and air bubbles coming off of it. Careful not to breath in any powder.
- When there is no more clumps present, you have successfully make washing soda! Test it with a pH test strip to confirm – it should have a pH of 11.
- Transfer washing soda into an airtight container (this is important as we don’t want to reintroduce water molecules into the equation!).
In action: cleaning stainless steel
- Bring some water to a boil in a large enough pot
- Add in 2 tablespoon of washing soda and some liquid soap
- Drop in any dirty stainless steel cookware
- Let it boil for 1 minute and remove with care
- Rinse under cold water and scrub stains with a towel. The stains should come off with ease.
This is how we make washing soda at home, we hope you learned something new!
