E500I - Sodium carbonate

At a glance

• Name: Sodium carbonate; also called washing soda; E-number E500i
• Roles in food: acidity regulator, stabiliser, thickener, base in leavening systems
• Typical uses: baked goods, alkalised (Dutched) cocoa, some noodles and pretzels, and other processed foods
• Part of the E500 group: the sodium carbonates family sodium carbonates
• Labeling: may appear as “sodium carbonate,” “soda ash,” “E500,” or “E500(i)”
• Taste/chemistry: strongly alkaline; small amounts can noticeably raise pH
• Dietary: an inorganic mineral salt; suitable for vegetarian and vegan diets

Why is Sodium carbonate added to food?

Manufacturers use sodium carbonate to control acidity (raise pH), stabilize textures, and act as the alkaline “base” in leavening systems that release carbon dioxide when combined with an acid such as citric acid. In the European Union it is the E-number E500i within the approved “sodium carbonates” group, with food-grade identity and purity specifications defined by law.¹ Chemically, sodium carbonate is Na2CO3, a basic salt that neutralizes acids and shifts recipes toward alkalinity.²

An alkaline environment can also drive browning and flavor development in certain foods. For example, cocoa may be “alkalised” with approved alkalis (including sodium carbonate) to darken color and mellow acidity.³

What foods contain Sodium carbonate?

You’re most likely to see sodium carbonate in:

• Baked goods and crackers, as part of a leavening blend with acid salts
• Alkalised (Dutched) cocoa and chocolate products, where alkali is permitted to adjust flavor and color³
• Alkaline-style noodles and traditional pretzel-making, where controlled alkalinity affects texture and browning
• Various processed foods that need small pH adjustments for stability or texture

On labels it may appear by name, as “E500,” or “E500(i).”

What can replace Sodium carbonate?

Depending on the job it’s doing:

• As a leavening base: sodium bicarbonate (baking soda) or other bases in leavening systems; acid partners include monocalcium phosphate or disodium diphosphate.
• To raise pH (alkalinity): potassium carbonates can substitute when sodium must be limited; some applications may use sodium hydroxide at much lower levels for stronger alkalinity.
• For general buffering/emulsified systems: sodium phosphates are common alternatives.
• For specific aeration in low-moisture doughs and crackers: ammonium carbonates are sometimes used.

The best substitute depends on recipe, target pH, sodium limits, and processing method.

How is Sodium carbonate made?

Food-grade sodium carbonate comes from two main routes:

• Natural soda ash: mined trona ore (primarily in Wyoming, USA) is refined to sodium carbonate.
• Synthetic “Solvay” process: brine (sodium chloride) and limestone (calcium carbonate) are reacted in the ammonia-soda process to yield sodium carbonate.

Both routes are well established in industry; the United States largely relies on natural trona, while many other regions use the Solvay process.⁴

Is Sodium carbonate safe to eat?

Yes—when used as intended and within good manufacturing practice (GMP). In the U.S., sodium carbonate is listed by FDA as Generally Recognized as Safe (GRAS) for use in food.⁵ In the EU, it is authorized as E500i within the sodium carbonates group, with binding purity specifications.¹

Like any alkaline ingredient, undissolved or overly concentrated sodium carbonate can be irritating; in foods it is used at small, controlled levels to achieve the desired pH and functional effect.

Does Sodium carbonate have any benefits?

In food processing and cooking, sodium carbonate:

• Regulates acidity to stabilize flavor and texture
• Acts as a leavening base when paired with an acid, helping doughs release carbon dioxide
• Encourages browning and characteristic flavor in some baked goods and snack treatments by raising surface pH
• Enables milder, darker “Dutched” cocoa via permitted alkalisation³

These effects can improve consistency, taste, and appearance.

Who should avoid Sodium carbonate?

• People on sodium-restricted diets (for hypertension, kidney disease, or heart failure) may want to limit total sodium intake from all sources; while sodium carbonate is used in small amounts, it still contributes to overall sodium.⁶
• Individuals with known sensitivity to highly alkaline foods should be cautious with products that are intentionally alkalised.

If you have a medical condition requiring strict sodium control, check labels and discuss choices with a clinician or dietitian.

Myths & facts

• Myth: Sodium carbonate and baking soda are the same. Fact: They are related but not identical; baking soda is sodium bicarbonate, which is less alkaline and behaves differently in recipes.
• Myth: It is only a cleaning chemical. Fact: Food-grade sodium carbonate is a regulated additive used in small amounts for pH control and leavening.
• Myth: E-numbers are unsafe. Fact: E-numbers mean the additive is authorized in the EU with defined identity and purity; E500i is one of the sodium carbonates.¹
• Myth: It always makes food taste soapy. Fact: At correct levels, it adjusts pH without imparting off-flavors; excessive use can cause undesirable taste.

Sodium carbonate in branded foods

On packaged foods, you might see it listed as:

• Sodium carbonate
• E500 or E500(i)
• Soda ash (less common on retail labels)

It often appears within leavening blends (paired with acid salts) or near other processing aids in the ingredient list.

References

Footnotes

1. Commission Regulation (EU) No 231/2012 — Specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008 (includes E500 sodium carbonates). https://eur-lex.europa.eu/eli/reg/2012/231/oj ↩ ↩² ↩³

2. Sodium carbonate — PubChem (NIH). https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-carbonate ↩

3. 21 CFR 163.110 — Chocolate and cocoa products; optional alkali ingredients (includes sodium carbonate). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-163/section-163.110 ↩ ↩² ↩³

4. Soda Ash Statistics and Information — U.S. Geological Survey (USGS). https://www.usgs.gov/centers/national-minerals-information-center/soda-ash-statistics-and-information ↩

5. Food Additive Status List — U.S. Food and Drug Administration (FDA). https://www.fda.gov/food/food-additives-petitions/food-additive-status-list ↩

6. About Sodium — Centers for Disease Control and Prevention (CDC). https://www.cdc.gov/salt/ ↩