The Applications and Formula of Baking Powder

Baking powder is an important ingredient in baking. Bakers commonly use it to make cakes, cookies, and other baked treats. The main parts are:

- Weakly alkaline baking soda (sodium bicarbonate)

- Acidic powders (like cream of tartar or alum)

- Fillers such as cornstarch Together, these ingredients make a great leavening agent.

People prize baking powder, also known as leavening powder or fermentation powder, for its unique leavening effects. It comes in sweet and edible types. It acts quickly as a leavening agent, especially for fast fermentation in grain products. It plays a crucial role in making cakes, steamed buns, bread, pastries, and more.

When baking powder meets water, its acidic and alkaline parts dissolve and react. This reaction releases carbon dioxide (CO₂) gas. During baking, the heat releases additional gas, causing the product to expand and achieve a light, fluffy texture.

Baking powder can also be categorized by reaction speed:

• Fast-acting – Reacts immediately upon mixing with moisture.
• Slow-acting – Reacts primarily under heat.
• Double-acting means it has both fast and slow reactions. It contains two acidic compounds. These compounds release CO₂ at different times, during mixing and baking. This ensures the dough rises consistently.

Although baking powder contains baking soda, someone carefully balances its pH with acidic agents, making it neutral. Therefore, you should not substitute it with plain baking soda. Proper acid-alkali balance is essential for optimal leavening.

Chemical Reactions & Key Functions

When the acid in baking powder reacts with sodium bicarbonate, CO₂ bubbles form, providing volume but sometimes lacking softness. The acid also interacts with proteins, improving texture. Cornstarch acts as a stabilizer, preventing premature reactions while adjusting texture and expansion.

Key Functions of Fillers

1. Separates acidic and alkaline components to prevent premature reaction due to moisture.
2. You can change the reaction strength by using fillers. Some examples are calcium carbonate, calcium sulfate, calcium lactate, or calcium silicate. Calcium lactate, when paired with sodium acid pyrophosphate, slows the reaction time.

Common Baking Powder Formulas & Reactions

1. Cream of Tartar-Based (Fast-Acting)

A quick-reacting formula that releases CO₂ upon mixing.

Typical composition:

• Sodium bicarbonate
• Tartaric acid
• Potassium bitartrate (cream of tartar)
• Cornstarch

Reaction:

Potassium bitartrate + Sodium bicarbonate → CO₂ + Potassium sodium tartrate + Water

(KHC₄H₄O₆ + NaHCO₃ → CO₂ + KNaC₄H₄O₆ + H₂O)

Tartaric acid reacts similarly but is rarely used alone:

*(H₂C₄H₄O₆ + 2NaHCO₃ → Na₂C₄H₄O₆ + 2CO₂ + 2H₂O)*

2. Phosphate-Based (Double-Acting)

An early phosphate-based formula uses monocalcium phosphate (MCP).

Reaction:

*3Ca(H₂PO₄)₂ + 8NaHCO₃ → Ca₃(PO₄)₂ + 4Na₂HPO₄ + 8CO₂ + 8H₂O*

MCP reacts quickly at room temperature but may cause spotting on baked surfaces.

3. Sodium Acid Pyrophosphate (Slow-Acting)

A delayed-reaction formula often paired with calcium lactate.

Reaction: Produces sodium pyrophosphate and disodium phosphate.

Note: Excess sodium pyrophosphate can leave a bitter aftertaste, but calcium compounds mitigate this.

Effects on Baked Goods

• Volume expansion and improved crumb structure—phosphates enhance air cell formation, yielding a fine, elastic texture.
• Strengthens protein networks, preventing air cell collapse.
• Phosphate ions increase water absorption, keeping products moist.

Alternative Leavening Agents

• Ammonium bicarbonate & ammonium carbonate – Used in low-moisture products like cookies. They decompose completely, leaving no residue:
• *2NH₄HCO₃ → 2NH₃ + 2CO₂ + 2H₂O*
• Ammonium bicarbonate is more stable and commonly preferred.

Usage Guidelines

• Mix 2-3% baking powder with flour (excess causes bitterness).
• Add cold/warm water, knead, and allow fermentation before baking.

Testing Freshness

Mix 2.5g baking powder with 45ml warm water. Fresh powder will bubble vigorously; if it doesn't react, it has expired. Replace every 3 months for best results.

Safety Note on Alum-Based Powders

Potassium alum, used in fried dough and noodles, may pose health risks (osteoporosis, anemia, neurotoxicity) if overconsumed. Experts advise moderation.

Common Baking Powders in France

(Further details to be expanded.)

• This revised version maintains technical accuracy while improving readability for an international audience. Let me know if you'd like any refinements!