- Hot oven will transform it from sodium bicarbonate into sodium carbonate, a stronger alkaline salt.
- By tracking the change in weight of the baking soda as it bakes, you will know when the transformation from bicarbonate to carbonate is complete.
Heating baking soda makes it transform from sodium bicarbonate into sodium carbonate, which is a stronger alkaline salt. Baked soda is useful for applications in which a strong alkaline salt.
Preheat oven to 350°F.
Line a rimmed baking sheet with foil. Note the weight of the foil-lined baking sheet using a digital scale. Spread in an even layer and place baking sheet in oven.
Bake, stirring the baking soda every half hour, until the weight of the baking soda is reduced to 613g (~21 oz), which is 2/3 of the starting weight (weigh the baking sheet with the baking soda, then deduct the recorded weight of the lined baking sheet to determine the weight of the baking soda itself). The amount of time this can take can vary quite a bit, anywhere from 2 to 5 hours.
Remove from the oven and, when cool, store in an airtight container; be careful not to handle the baked baking soda with bare skin.Notes
Do not let the baked baking soda come in contact with your skin, as it is a caustic substance. If you do make contact with the baked baking soda, flush the area thoroughly with water.
Make-Ahead and Storage
Sealed in an airtight container, the baked baking soda will keep indefinitely.