Pure Blue needs only a few drops adding to liquid to achieve a beautiful blue colour. It is a totally natural, versatile product which is extracted from the butterfly pea flower. It can be used in a variety of ways, but its main use is in cocktails, it can also be used as a natural blue food colouring. If acidic liquids such as lemon or lime are added the colour changes from blue to purple/pink (dependant upon the amount of acidic liquid that is present or added). Add Pure Blue to the water when making ice cubes and then pop them into your drink and as the ice cube melts, watch the colour change to blue or through a range of colours if acidity is present in your drink/cocktail.