E-numbers / Other additives / E456
also: A-5D K/SD · polyaspartate
A polymer of the amino acid aspartate, used only in wine to stop tartrate crystals forming. No consumer health concern has been identified.
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Grapes, Stabilisers (Potassium Polyaspartate, Acacia Gum), Preservative (Potassium Bisulphite), Antioxidant (Ascorbic Acid), Packaging Gas (Nitrogen).
Concluded no safety concern from use in wine up to 300 mg/L; estimated intakes gave a margin of roughly 550 below the no-effect level.
51
of the 43,325 UK supermarket foods we checked declare E456 in their ingredients
That is 0.1%, counted by its code or its name.
Counted by NutraSafe from UK supermarket ingredient lists, September 2026. How we counted
Why it’s worth knowing. Concluded no safety concern from use in wine up to 300 mg/L; estimated intakes gave a margin of roughly 550 below the no-effect level. No chronic or reproductive testing requested.
Potassium polyaspartate is a synthetic polymer built from aspartic acid, a naturally occurring amino acid. It is produced by polymerising aspartic acid and converting the result to its potassium salt. The result is a large, water-soluble molecule with a negative charge.
In wine, tartaric acid and potassium ions naturally combine to form tartrate crystals, which appear as harmless gritty deposits or crystalline sediment. Potassium polyaspartate inhibits this crystal growth by binding to the crystal nuclei and blocking their development. The effect is similar to carboxymethylcellulose (E466) and metatartaric acid (E353), but potassium polyaspartate is more heat-stable and its effect is longer-lasting. It does not affect taste, colour, or aroma.
Used exclusively in wine, including red, white, and rose. Typical use levels are 100 to 200 mg per litre, with a maximum of 300 mg per litre. It will not commonly appear on wine labels because wine is exempt from the standard ingredient-list requirement under EU and UK law. When labelling is required it would appear as 'potassium polyaspartate' or 'E456'.
The European Food Safety Authority reviewed the safety of potassium polyaspartate in 2016. Based on available metabolism, genotoxicity, and toxicology data, EFSA concluded there was no safety concern at the proposed use level of 300 mg/L in wine. No numerical acceptable daily intake was set because the exposure at these wine-only levels was considered low.
EFSA concluded there was no safety concern for potassium polyaspartate used as a stabiliser in wine at a maximum level of 300 mg/L, finding no genotoxic, subchronic, or chronic toxicity signals in the data package reviewed.
Polyaspartate is a polymer of aspartic acid. Once consumed, it is expected to break down into aspartic acid, a non-essential amino acid found in many foods. The quantities reaching the consumer in wine at permitted levels are small. No accumulation or unusual metabolic pathway has been identified.
Aspartic acid, the breakdown product of potassium polyaspartate, is a common dietary amino acid present in meat, eggs, and plant foods, with established safety at normal dietary intake levels.
No specific population group is identified as needing to avoid potassium polyaspartate on health grounds. People avoiding alcohol avoid the only category it appears in. Look for 'E456' or 'potassium polyaspartate' on any wine label that carries a full ingredient list.
This additive is specific to winemaking and has a narrow technical role. The science reviewed by EFSA before its 2017 EU authorisation did not raise toxicological concerns. The main open question is not about safety but about UK regulatory status: the additive was added to the EU permitted list after Brexit, so whether it is currently covered by the UK assimilated register is worth confirming with the UK FSA directly. For the wine drinker, the quantities involved are small and the breakdown product is a dietary amino acid.
Its EU approval came in July 2017, after the Brexit reference date of January 2020, so it should have been included in assimilated UK law. However, E456 did not appear on the UK FSA approved-additives summary page when checked in June 2026. The position needs to be confirmed directly with the UK FSA or by checking the UK food additives register.
Wine naturally contains tartaric acid and potassium, which can combine to form tartrate crystals, the gritty white or translucent deposits sometimes found in wine bottles. Potassium polyaspartate blocks crystal growth, keeping the wine looking clear without affecting flavour or aroma.
Only wine. It is authorised in the EU exclusively as a wine stabiliser and is not approved for use in any other food category.
Potassium polyaspartate is synthesised from aspartic acid and does not involve animal-derived raw materials. It is considered vegan and vegetarian. However, wine production uses various processing aids, so the overall vegan status of a specific wine depends on all processing steps, not only this additive.
Last reviewed: 20 June 2026
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