The ability to stay fresh for 28 days has to do with the high quality ingredients that we've chosen, the process of baking, and the way in which we handle the product after it's been baked. Of course, we have to add a preservative, but we use the same preservative that has been widely used in bakery products for decades and in extremely low concentrations. Potassium sorbate (Labelled as preservative 202) is used to inhibit moulds and yeasts in many foods, such as cheese, wine, yoghurt, dried meats, apple cider, rehydrated fruits, soft drinks, fruit drinks, herbal dietary supplements and baked goods! You can see a full list of our ingredients on our product pages.