Yeast extract and autolyzed yeast extract may contain gluten from barley. Manufacturers are not required to disclose the source of yeast extract on the ingredients label, so you should only use yeast extract that is labeled gluten-free or confirmed gluten-free by the manufacturer.

How much gluten does yeast extract have?

The most common brand in the UK of yeast extract is Marmite which is not suitable as it contains more than 20 parts per million (ppm) of gluten. There are other brands of yeast extract which are suitable for a gluten free diet and they can be found in our Food and Drink Directory, search "yeast extract".

What is yeast extract made of?

Yeast extract is made by adding sugar to yeast in a warm environment. As the yeast expands, the walls of its cells soften. This mixture is then spun in a centrifuge and the loosened cell walls are whisked away. There are two kinds of yeast extract, autolyzed and hydrolyzed.