It is the live part of the yeast that contains the allergen. Allergies are always molecule specific and in order to stimulate a yeast allergy, the yeast must still be in possession of its long chain molecules. During the growing process, the yeast cell wall is broken down using a natural enzyme. This makes it unrecognisable as a yeast molecule and it does not, therefore, trigger off the allergic response. There is no 'live yeast' present in any of our products and there have been no known allergic reactions to the yeast used in our products.