If you’ve come across washing soda in a cleaning recipe and didn’t understand what the difference was from baking soda, then look no further. Washing soda is natural cleaning booster that elevates favorite products. What makes baking soda different from washing soda? Water and carbon dioxide.
OK, here are the technicals — baking soda’s chemical makeup is NaHCO3, while washing soda’s is Na2CO3. Basically, heating baking soda at a high temperature evaporates water and releases carbon dioxide, resulting in the change. Baking soda is commonly used in baking as a leavening agent, but minus the water and carbon dioxide, and it becomes a concentrated alkaline laundry booster that helps remove stubborn stains — and is not meant for use in cooking at all.
You need: 1 cup baking soda, shallow pan and parchment paper.
The process is really simple. Just heat your oven to 400 F (or 200 C), sprinkle some baking soda on a shallow pan, and bake it for about half hour, until it changes composition. You should also stir it up occasionally, just so that it bakes more evenly.
So how do you know when it changes into washing soda? Baking soda is powdery, crystallized like salt, and clumps together. Washing soda is grainy, dull and opaque, and is separate grains.