E501 - Potassium carbonates

At a glance

• What it is: A group of alkaline salts of potassium, mainly potassium carbonate and potassium bicarbonate, labeled as E501
• What it does: Works as an acidity regulator, stabiliser, and leavening base that releases carbon dioxide when paired with an acid
• Where it appears: Dutch‑processed cocoa, some baking powders and mixes, and selected confectionery and beverage products
• Safety status: Permitted in both the EU and the U.S. for use in food at good manufacturing practice levels
• Watch-outs: People who must limit potassium (for example, some kidney or heart conditions) should check labels and ask a healthcare professional

Why is Potassium carbonates added to food?

Food makers use potassium carbonates to adjust pH (how acidic or alkaline a food is) and to stabilise texture and flavor. As a leavening base, it reacts with food acids (such as citric acid or leavening acids like monocalcium phosphate) to release carbon dioxide, helping doughs and batters rise. In the EU, E501 is authorised as an acidity regulator and raising agent; specifications cover two forms: E 501(i) potassium carbonate and E 501(ii) potassium hydrogen carbonate (potassium bicarbonate).¹²

What foods contain Potassium carbonates?

You will most often see E501 in:

• Cocoa powders labeled “processed with alkali” (also called Dutch‑processed cocoa), where alkalisation mellows flavor and darkens color³
• Baking mixes and baking powders formulated to be lower in sodium, where potassium bicarbonate can replace part or all of sodium bicarbonate²
• Selected confectionery and beverages where pH control is needed¹

Look for “potassium carbonate,” “potassium bicarbonate,” “E501,” “E501(i),” or “E501(ii)” on ingredient lists.²

What can replace Potassium carbonates?

Possible alternatives depend on the job you need done:

• For leavening: sodium carbonates or ammonium carbonates, used with suitable leavening acids like diphosphates or monocalcium phosphate
• For pH control: Organic acids and their salts (for example, citric acid or potassium citrates)
• For cocoa alkalisation: Other approved alkalising agents may be used where allowed by the product standard³

How is Potassium carbonates made?

Food‑grade potassium carbonate is typically produced by reacting potassium hydroxide with carbon dioxide to form potassium bicarbonate, which is then heated to make potassium carbonate; potassium bicarbonate can also be produced and used directly. Both materials are highly soluble, alkaline salts of potassium, and they are specified for identity and purity in EU additive specifications.⁴²

Is Potassium carbonates safe to eat?

Yes—when used as intended. In the European Union, E501 (both potassium carbonate and potassium hydrogen carbonate) is authorised as a food additive with detailed specifications for purity.¹² In the United States, potassium carbonate is affirmed as Generally Recognized as Safe (GRAS) for specified uses in food under good manufacturing practice.⁵

Does Potassium carbonates have any benefits?

In food processing, the main benefits are technical:

• Controls acidity to keep taste, texture, and color consistent
• Helps baked goods rise when used with a leavening acid
• Can reduce sodium in baking by using potassium bicarbonate in place of some sodium bicarbonate

Potassium is an essential mineral for humans, but the small amounts from additives are not a meaningful source of dietary potassium for most people.⁶

Who should avoid Potassium carbonates?

Most people do not need to avoid E501. However, those who must limit potassium—such as people with kidney disease, certain heart conditions, or those taking potassium‑sparing diuretics or ACE inhibitors—should follow medical advice and check labels.⁶

Myths & facts

• Myth: It is the same as harsh “lye.” Fact: E501 includes potassium carbonate and potassium bicarbonate, which are milder alkaline salts than sodium hydroxide (lye).
• Myth: It adds a strong taste. Fact: At normal use levels, its main role is pH control and leavening; it is not added for flavor.
• Myth: “Dutch‑processed” cocoa always contains chemicals. Fact: Alkalisation is allowed using approved agents like potassium carbonates, and it is a long‑established, regulated process.³

Potassium carbonates in branded foods

You may find E501 listed on:

• Dutch‑processed cocoa powders and products made with them
• Low‑sodium baking powders and baking mixes that use potassium bicarbonate
• Selected candies and beverages where acidity and stability need fine control

On labels, look for “potassium carbonate,” “potassium bicarbonate,” “E501,” “E501(i),” or “E501(ii).”²

References

Footnotes

1. Regulation (EC) No 1333/2008 on Food Additives — European Union. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R1333 ↩ ↩² ↩³

2. Commission Regulation (EU) No 231/2012 (Food additive specifications, incl. E 501) — European Union. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R0231 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

3. Directive 2000/36/EC on cocoa and chocolate products — European Union. https://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:32000L0036 ↩ ↩² ↩³

4. Potassium carbonate (Compound Summary) — NIH PubChem. https://pubchem.ncbi.nlm.nih.gov/compound/Potassium-carbonate ↩

5. Potassium carbonate, 21 CFR §184.1619 — U.S. FDA/eCFR. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-184/subpart-B/section-184.1619 ↩

6. Potassium Fact Sheet for Health Professionals — NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/ ↩ ↩²