Baking soda and baking powder look, sound, and feel similar, but anyone who has ever tried substituting baking soda for baking powder most definitely knows that they are not the same. This article explores what baking soda and baking powder are, their history, and the chemistry behind the reactions they create.
Originally, bread was let to raise overnight. Yeast in the air would digest the sugar and produce gases such as CO2 (Green, 2016). This caused the bread to rise. As one might imagine, this process took awhile and was not very efficient. The process could be expedited by saving some of the raw dough for the next time bread was made. In fact, this is still done today in special circumstances (Green, 2016). However, more efficient bread-making recipes are commonly used.
The recipes mentioned above began to be created in the 1830s when baking soda came about. Baking soda is the first leavener to put a large dent in the time waited for bread to rise. It consists of pure sodium bicarbonate (NaHCO3) and was originally made from sodium-rich marine plants. Today, it is mined (Green, 2016). Cream of tartar was the next leavener to hit it big; a mixture of baking soda, cream of tartar, and water would cause CO2 bubbles to be produced. The results gained from cream of tartar were more consistent than those of baking soda, but supply easily fluctuated (Green, 2016).
Finally, in 1856, Eben Horsford figured out how to make monocalcium phosphate, an acid, from beef bones. He mixed the monocalcium phosphate with baking soda and cornstarch and began to market ‘Horsford’s Bread Preparation’, what we know today as baking powder (Green, 2016). Monocalcium phosphate, being an acid, reacts with the baking soda to create CO2. To slow this reaction, cornstarch is added in. The cornstarch keeps everything dry and prevents the reaction from occurring completely and right away. However, the reactions will still occur, though at a much slower rate, which is why baking powder has an expiration date (Green, 2016). Most baking powder sold in the United States today is mined and double-acting. Double-acting means exactly what it sounds like, it acts twice. There are two acids in double-acting baking powder. One acid begins to fully react when it hits liquid while the other reaction starts when the batter hits heat. While there are other leaveners available, these three are the most common (Green, 2016).
Baking soda is a naturally alkaline ingredient; is pure sodium bicarbonate; and must have an acid to react. This acid, in the context of baking, can be anything from brown sugar to buttermilk to yogurt (Arias, 2015). The baking soda begins to react as soon as the ingredient hits the liquid, but then continues to react as heat is added. It is important for the batter to be placed in the oven as soon as possible in order that the wait time might be minimized. Too much time in between results in a flatter product. An excess amount of baking soda will lend a very unpleasant taste to the dish; elevate the pH; and darken the color (Arias, 2015). Also, baking soda has a much stronger taste when compared to baking powder. Just like baking powder, baking soda must be fresh. It’s freshness is able to be tested simply by dropping vinegar onto a small sample. If bubbles form, then it is still good for use (Arias, 2015).
Baking powder is a mixture of baking soda, cornstarch, and one or more acids. Because it contains both an acid(s) and a base, there does not need to be an acid present in the recipe in order for a reaction to occur. All baking powder needs is liquid and/or heat (Arias, 2015). Baking powder can be made at home and ahead of time; nonetheless, it is essential, just as with baking soda, that it be fresh. It’s freshness may be tested by pouring hot water onto it. If bubbling occurs, then it is still fresh enough to use (Arias, 2015).
The main differences between baking soda and baking powder are that baking powder does not need an acid in the recipe in order to react while baking soda does and that they both taste differently. Baking soda has a much stronger taste than baking powder and can easily ruin a recipe if too much is mixed in. If in a pinch, baking powder is able to stand in for baking soda, but around four times the amount is necessary (Arias, 2015). Generally speaking, baking soda should never replace baking powder unless the baker is in dire need. Baking powder graciously bestows a very unpleasant taste to recipes in which it does not belong. While there might be a few situations where one could get away with the exchange, the result would not be the same if baking powder had been used. Though these two are similar in many ways and even contain a shared ingredient, they are two separate entities for a reason, and many taste-buds will thank you for treating them as such.
Arias, Tessa. (Producer). (2015, April 29). Baking Powder vs. Baking Soda: The Difference. Podcast retrieved from www.youtube.com/watch?v=E3OrOuL56uI
SciShow. (Producer). (2016, November 14). What’s the Difference Between Baking Powder and Baking Soda? [Episode 5]. Stuff Your Face . . . with Science! Podcast retrieved from www.youtube.com/watch?v=GXRouroc_ZY&list=PLsNB4peY6C6L8IwJK8VadUJburLKTBgAR&index=5