E150a

Plain Caramel

Last reviewed: 7 May 2026

The first of four caramel classes — and the only one made without ammonia or sulphites

The four caramel classes at a glance

All four are derived from heated sugar (sucrose, glucose, or invert sugar). What changes between them is the reactant added to the sugar during processing — and that determines what trace compounds end up in the finished colour.

Class	Made with	Distinctive trace	Typical UK uses
E150a Plain Caramel (Class I)	Sugar only, heated 120–180°C	No 4-MEI, no sulphites	Dark beer, stout, whisky, rum, gravies, soy sauce, brown sauces
E150b Caustic Sulphite Caramel (Class II)	Sugar + sulphites	Sulphite residues — may trigger reactions in sulphite-sensitive asthmatics	Some brandies, malt vinegars, certain spirits
E150c Ammonia Caramel (Class III)	Sugar + ammonia	Trace 4-MEI	Some beers, baked goods, gravy mixes, biscuits
E150d Sulphite-Ammonia Caramel (Class IV)	Sugar + ammonia + sulphites	Highest 4-MEI of the four; sulphite residues	Major colas (typically Coca-Cola, Pepsi), some dark soft drinks

That's the whole disambiguation: ammonia produces 4-MEI; sulphites produce sulphite residues; E150a uses neither. Everything else on this page is detail.

What E150a actually is

E150a is the simplest caramel colour to produce. The starting material is a food-grade sugar — sucrose, glucose, or invert sugar — and the only thing done to it is heat. The sugar is taken to 120–180°C, where caramelisation reactions break the sugar molecules apart and recombine the fragments into longer brown-coloured polymers. The result is a viscous, deeply coloured liquid (or a dried powder version) that can be added to other foods to standardise their brown tone.

Two things follow from "no other reactant":

• No 4-methylimidazole. 4-MEI is formed when ammonia reacts with sugar fragments during caramelisation. Without ammonia in the pan, that reaction can't run. E150a, by definition, does not contain it.
• No sulphite residues. Sulphites are the second reactant introduced in classes II and IV. E150a doesn't use them, so there's no sulphite to declare and nothing to flag for sulphite-sensitive asthmatics.

The chemistry is the same Maillard-and-caramelisation set of reactions that browns a roasted onion or a piece of toast. The industrial version is more controlled — temperature, time, and pH are tuned for a specific shade and tinctorial strength — but the underlying transformation is sugar to brown polymer.

Where you'll see E150a on UK labels

E150a is the workhorse caramel colour for products where its mild flavour and deep brown tone are wanted, but where a manufacturer doesn't need the high-acid or high-salt stability of the ammonia-based classes. On a UK shop shelf you'll typically find it in:

• Dark beers and stouts — including Guinness and many porters, where caramel colour is used to top up the depth that comes from roasted malt.
• Whisky and rum — to standardise colour batch-to-batch. Scotch whisky regulations specifically permit E150a as the sole permitted colour additive.
• Gravies and gravy granules — for the rich brown of pan-juice colour.
• Soy sauce and brown sauces — naturally brown already, with E150a used to standardise.
• Dark vinegars — malt vinegar and some balsamic-style vinegars.
• Bakery glazes, dark biscuits, malt loaves — where a deep brown crumb or surface is wanted.

Important: the major colas don't use E150a. Coca-Cola and Pepsi typically use E150d for the acid-stable, salt-stable colour required to hold up in their formulations. Seeing "caramel colour" on a cola label and assuming it's E150a is the most common mix-up readers make on this topic.

E150a vs E150d: the cola question

This is the comparison that drives most of the public conversation about caramel colour, so it's worth being precise about what the science says rather than what the headlines suggest.

4-methylimidazole (4-MEI) is a small nitrogen-containing molecule that forms when ammonia is present during caramelisation. It is therefore present at trace levels in E150c, and at higher trace levels in E150d, where both ammonia and sulphites are used. It is not present in E150a or E150b, because no ammonia is involved in their production.

The reason 4-MEI gets attention is California Proposition 65, which lists it as a chemical "known to the State to cause cancer" based on long-term high-dose rodent studies. Under Prop 65, products sold in California require a cancer warning label when expected daily exposure exceeds 29 micrograms — the "no significant risk level" the state's regulators set. That threshold is what prompted Coca-Cola and Pepsi to reformulate their US E150d to lower 4-MEI content.

The European position differs. EFSA's 2011 re-evaluation of E150a–E150d set a group Acceptable Daily Intake of 300 mg/kg body weight per day for the four caramel colours combined, with a more restrictive ADI of 100 mg/kg bw/day specifically for E150c. EFSA concluded that 4-MEI exposure from E150c and E150d at typical European intake levels stays well within the ADI, and did not require a label warning.

For a UK reader, the practical takeaway is narrow: if you're choosing to limit 4-MEI specifically, that's an E150c / E150d question. E150a does not contain 4-MEI, regardless of how much you consume.

Regulatory status

E150a is authorised across the major regulatory bodies:

• UK and EU. Authorised under retained EU food additive regulations. EFSA's 2011 re-evaluation set a group ADI of 300 mg/kg bw/day for E150a–E150d combined, with no specific concerns flagged for E150a.
• United States. FDA "Generally Recognized As Safe" (GRAS) status; sold under the name "Caramel Color Class I". No usage restriction.
• Codex Alimentarius / JECFA. Reviewed under INS 150a, with the same group ADI framework.

Approval status describes what regulators have authorised, not what we recommend or how much you should consume. Per CLAUDE.md voice rules, we don't translate regulatory clearance into reassurance — we just state what's been approved and let the reader decide what to do with the food in their hand.

How to read the caramel colour line on a UK label

UK and EU food labelling rules require caramel colour to be declared with its class letter. Three patterns you'll see:

• "E150a" or "Plain caramel" — Class I. Sugar only.
• "E150b" / "E150c" / "E150d" — or the equivalent name (caustic sulphite caramel, ammonia caramel, sulphite-ammonia caramel). Each is its own additive entry.
• "Caramel colour" with no letter — non-compliant on EU/UK retail packs since the 2010 labelling reform. You'll usually see this pattern only on imported (often US) products. On a US-style label, "caramel color" alone gives you no way to tell which class is in the bottle without contacting the manufacturer.

If the ingredient list says "Colour: Plain Caramel (E150a)", that's E150a. If it just says "Colour (E150d)", that's the sulphite-ammonia variant. The class letter is the only piece of information that disambiguates the four.

One more pattern worth knowing: caramel colour usually appears low in an ingredient list because it's used at small inclusion rates — typically tenths of a percent by weight in soft drinks, and lower still in beers and sauces. Its position in the ingredient list isn't a reliable signal of how much you're consuming; the class letter is what changes the chemistry, not the order it appears in.

Make caramel colour at home

The home-kitchen version of E150a is the same chemistry, scaled down. Useful in gravies, marinades, cake browning, or homemade cola.

1. Put 100 g of white sugar into a heavy-bottomed pan over medium-high heat. No water, no stirring.
2. Wait. The sugar will melt at the edges, then bubble through golden, amber, and dark mahogany over 5–8 minutes.
3. When the colour reaches a deep mahogany — just before it turns acrid and starts to smoke — take the pan off the heat.
4. Stand back and add 100 ml of hot water in a slow stream. It will spit and steam violently. Stir until the seized caramel re-dissolves into a smooth dark syrup.
5. Cool. The result is a liquid caramel colour suitable for a teaspoon-at-a-time addition to gravies, sauces, dark cakes, or cola syrup. Store refrigerated.

Industrially, E150a is held at temperature for longer and standardised for tinctorial strength (colour units per gram), but the kitchen version is functionally the same ingredient.