What is 1 tsp Bicarbonate of Soda and What Does It Do?

January 2, 2026 •

2 min read

One US teaspoon of bicarbonate of soda contains approximately 4.6 grams of pure sodium bicarbonate. More than just a baking ingredient, this measure of an alkaline chemical compound has a wide range of uses, from leavening baked goods to tackling tough household cleaning tasks. Understanding what bicarbonate of soda is and how it functions reveals its surprising power and versatility in and out of the kitchen.

Quick Summary

An alkaline chemical compound known as sodium bicarbonate, one teaspoon of bicarbonate of soda reacts with acids or heat to produce carbon dioxide. This chemical reaction makes it a powerful leavening agent for baking, a mild abrasive and deodorizer for cleaning, and a natural way to neutralize odors and stains.

Key Points

Chemical Composition: Bicarbonate of soda is pure sodium bicarbonate, an alkaline compound that reacts with acid.
Baking Leavening: When used in recipes with acidic ingredients, it releases carbon dioxide gas, causing doughs and batters to rise and become fluffy.
Household Cleaner: Its mild abrasive and deodorizing properties make it an effective, non-toxic cleaner for tasks like scrubbing pans and refreshing carpets.
Medical Cautions: While used as a short-term antacid, a teaspoon has high sodium content and should be used with caution, especially by individuals with certain health conditions.
Don't Confuse with Baking Powder: Bicarbonate of soda and baking powder are not the same; bicarb is stronger and requires a separate acid, while baking powder is a complete leavening agent.

The Chemical Reaction Behind the Rise

Bicarbonate of soda, or sodium bicarbonate ($NaHCO_3$), is an alkaline compound. When mixed with an acidic ingredient and moisture, it triggers a chemical reaction releasing carbon dioxide ($CO_2$) gas. These gas bubbles cause baked goods to rise and become light. Acids commonly used with bicarbonate of soda include buttermilk, yogurt, and lemon juice.

Unlike baking powder, bicarbonate of soda needs a separate acidic component. Without enough acid, it can give a bitter taste and yellowish color.

How Bicarbonate of Soda Leavens

Immediate reaction: Gas is released upon contact with wet, acidic ingredients, so quick baking is needed.
Thermal decomposition: Heat can also cause bicarbonate of soda to release carbon dioxide, but this is less efficient than the acid reaction.

Versatility Beyond Baking: Household Uses

Bicarbonate of soda is a cost-effective, eco-friendly cleaner and deodorizer. Its mild abrasive and deodorizing qualities make it useful for various tasks.

Practical household applications:

Deodorizing: Sprinkle in bins or place in an open container in the fridge to absorb smells.
Cleaning: Make a paste with water to scrub pans, or use with hot vinegar for slow drains.
Polishing: A paste can gently polish tarnished silver.
Refreshing: Sprinkle on carpet stains, let sit, then vacuum to lift odors.

Bicarbonate of Soda vs. Baking Powder

Understanding the difference is key when substituting. A teaspoon of each has different effects.


Feature	Bicarbonate of Soda (Baking Soda)	Baking Powder
Composition	Pure sodium bicarbonate.	Sodium bicarbonate, dry acid, and starch.
Activation	Needs an acid and liquid to produce $CO_2$.	Contains its own acid; activated by liquid and sometimes heat.
Power	Stronger leavening power (3-4 times baking powder).	Less potent.
Substitution (for bicarb)	Not a direct substitute for baking powder unless acid is added.	Substitution amounts vary (may affect taste/texture).

Health-Related Uses and Precautions

Bicarbonate of soda has been a traditional remedy. A small amount with water can temporarily relieve indigestion by neutralizing stomach acid. Some athletes use it for exercise, but consult a doctor first.

However, caution is vital due to high sodium content. A teaspoon has over 1,200mg of sodium, and overuse can cause electrolyte issues, vomiting, and other dangers. It is not for long-term use and should be avoided by pregnant women and those with heart or kidney conditions. For more information on safety and ingestion, consult medical guidelines from organizations like WebMD.

Conclusion

One teaspoon of bicarbonate of soda is a versatile ingredient. As pure sodium bicarbonate, it reacts with acid and moisture to produce carbon dioxide, useful in baking and household tasks. Unlike baking powder, it needs a separate acid. Its dual role makes it a kitchen essential. Use caution when consuming it due to its high sodium content.

Frequently Asked Questions

Bicarbonate of soda is pure sodium bicarbonate and requires an acid to react, whereas baking powder already contains an acid and a starch and is pre-mixed for convenience.

One US teaspoon of bicarbonate of soda contains approximately 4.6 grams of sodium bicarbonate.

While not a direct substitution, it may be possible with adjustments. Substitution ratios vary, and may affect taste and texture.

Using too much bicarbonate of soda can lead to a bitter, soapy taste in baked goods and may cause them to rise too quickly and then collapse.

You can make a paste with bicarb and water to scrub stains, sprinkle it to deodorize a trash can or fridge, or use it with vinegar to clean a drain.

It is sometimes used as a short-term remedy for indigestion. Its high sodium content can be dangerous, so it should be used cautiously and not for long-term treatment.

To test if it is still good, mix a teaspoon of bicarbonate of soda with a little vinegar. If it fizzes vigorously, it is still active and effective.