Glutamic Acid

How it's made

Made by fermentation.

Glutamic acid is an amino acid — a normal building block of protein found in virtually all protein-containing foods — used as a flavour enhancer to bring out savoury, "umami" taste. It is the parent acid of monosodium glutamate (MSG), delivering the same savoury boost in acid form.

For food use it is produced by fermentation, the same way MSG is made. Bacteria (such as Corynebacterium glutamicum) are grown on a sugar source — glucose or molasses — and are cultivated so that they overproduce glutamic acid and release it into the broth. This biological process replaced older extraction and chemical methods decades ago.

The glutamic acid is recovered from the fermentation liquid, purified and crystallised. It is chemically identical to the glutamate that occurs naturally in foods such as tomatoes, cheese and mushrooms, and in the body; as an additive it is used to deepen savoury flavour in soups, sauces and savoury snacks.