Main Difference – Baking Soda vs Baking Powder
A leavening agent is any compound that causes the expansion of the volume of a dough by releasing gases. The most common leavening compounds in bakery productions are baking soda, baking powder, dry yeast, steam, etc. Baking soda is pure sodium bicarbonate. Baking powder is a mixture of several chemical compounds including sodium bicarbonate, an acidifying agent and a drying agent. The main difference between baking soda and baking powder is that baking soda is a single compound whereas baking powder is a mixture of compounds.
Key Areas Covered
1. What is Baking Soda
– Definition, Mode of Action
2. What is Baking Powder
– Definition, Mode of Action
3. What are the Similarities Between Baking Soda and Baking Powder
– Outline of Common Features
4. What is the Difference Between Baking Soda and Baking Powder
– Comparison of Key Differences
Key Terms: Baking Powder, Baking Soda, Dough, Leavening Agent, Sodium Bicarbonate, Sodium Hydrogen Carbonate, Yeast
What is Baking Soda
Baking soda is pure sodium bicarbonate powder. It is a leavening agent. This means, when baking soda is added to a dough, it causes the expansion of the volume of the dough. The IUPAC name of sodium bicarbonate is sodium hydrogen carbonate. The chemical formula is NaHCO3, and the molar mass is 84.0066 g/mol.
Baking soda compound is a solid white crystalline compound. But it appears as a fine powder. It is an odorless compound with a slightly salty taste due to the presence of sodium. When heated, baking soda decomposes, forming sodium carbonate.
Figure 1: Baking Soda is a White Solid Compound
The major uses of baking soda include the production of baking powder, use as a leavening agent in cooking, as a pest controlling agent, as a mild disinfectant, etc. However, its most well-known application is as a leavening agent for bakery products.
Baking soda can react with acidic components in the dough. This reaction releases carbon dioxide gas (CO2). This gas gets trapped inside the dough instead of leaving the dough. This gas entrapping causes the volume of the dough to increase with time. Heat can also cause this volume expansion by thermally decomposing baking soda. This decomposition starts at about 80oC and results in sodium carbonate, along with the release of carbon dioxide.
2 NaHCO3 → Na2CO3 + H2O + CO2
What is Baking Powder
Baking powder is a mixture of sodium bicarbonate, an acidifying agent and a drying agent. The acidifying agent is usually cream of tartar, and the drying agent is starch. Baking powder is a leavening agent. It can increase the volume of a dough or batter mixture by releasing carbon dioxide gas. This released gas gets entrapped in the dough, causing the expansion of the dough. It also lightens the texture of the bakery item. Baking powder is used instead of yeast, which makes undesirable flavors due to the fermentation process.
Baking powder is available as either as a single-acting baking powder or a double-acting baking powder. Single-acting baking powder contains cream of tartar along with sodium bicarbonate. Double-acting baking powder contains about 30% of sodium bicarbonate along with monocalcium phosphate and sodium aluminium sulphate. These components combined with water, cause the release of carbon dioxide.
The single-acting baking powder is easily activated by moisture. Therefore, the product should be baked immediately after mixing the powder. But double-acting baking powder reacts in two phases. Hence, it can stand for a short time before baking.
The drying agent (usually starch) of baking powder is helpful in improving the stability. Cornstarch is often used for this. It can absorb moisture; thus, the shelf life is increased.
Similarities Between Baking Soda and Baking Powder
- Both contain sodium carbonate as components
- Both are leavening agents
- Both are used in bakery productions
- Both can expand the volume of a dough
Difference Between Baking Soda and Baking Powder
Definition
Baking Soda: Baking soda is pure sodium bicarbonate powder.
Baking Powder: Baking powder is a mixture of sodium bicarbonate, an acidifying agent and a drying agent.
Components
Baking Soda: Baking soda contains only sodium bicarbonate.
Baking Powder: Baking powder contains sodium bicarbonate, an acidifying agent such as cream of tartar and a drying agent such as corn starch.
Acidifying Agents
Baking Soda: Baking soda has no acidifying agents.
Baking Powder: Baking powder contains either cream of tartar or a mixture of monocalcium phosphate and sodium aluminium sulphate as the acidifying agent.
Drying Agent
Baking Soda: Baking soda has no drying agents.
Baking Powder: Baking powder contains starch (usually cornstarch) as a drying agent.
Time
Baking Soda: When baking soda is added, the product should be baked immediately.
Baking Powder: When single-acting baking powder is added, the product should be baked immediately after the mixing, but when double-acting baking powder is added, the dough can be kept for some time before baking.
Conclusion
Both baking soda and baking powder are composed of sodium bicarbonate. Sodium bicarbonate can react with acidic components in the dough and releases carbon dioxide. This carbon dioxide causes the expansion of the dough. The main difference between baking soda and baking powder is that baking soda is a single compound whereas baking powder is a mixture of compounds.
References:
1. “Leavening agent.” Encyclopædia Britannica, Encyclopædia Britannica, inc., 6 Apr. 2016, Available here.
2. “Baking powder.” BBC Good Food, Available here.
3. “Sodium bicarbonate.” Wikipedia, Wikimedia Foundation, 15 Dec. 2017, Available here.
Image Courtesy:
1. “baking soda shoot in studio” by Aqua Mechanical (CC BY 2.0) via Flickr
2. “9510” (CC0) via PEXELS
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