Potassium Sorbate
What it does
Preserves against mould/yeast.
How it's made
Potassium salt of sorbic acid, synthesised.
Potassium sorbate is the potassium salt of sorbic acid and one of the most common preservatives, used to prevent mould and yeast growth in cheese, wine, baked goods, dried fruits, dips and countless other products. It is favoured because it dissolves easily in water, unlike sorbic acid itself.
It is made by neutralising sorbic acid — produced by chemical synthesis — with a potassium base such as potassium hydroxide or potassium carbonate. The reaction converts the acid into its readily-soluble potassium salt, which is then purified.
The salt is crystallised or dried into a white to off-white powder or granules. In food it releases sorbic acid, which is the active preservative, working best in acidic conditions; because it is so soluble and effective at low levels, it is one of the go-to mould inhibitors across the food industry.
Possible reactions
Generally well tolerated; rare irritation.