Angostura bitters are made of water, alcohol, herbs and spices. These concentrated bitters are used for flavouring drinks (and sometimes for flavouring food). The exact formula of the Angostura bitters is a closely guarded secret. Angostura aromatic bitters is not bitter when added to a drink, but it has the ability to marry flavours. It works by enhancing the flavour of ingredients in drink preparations thereby bringing out the best in them without masking their true flavour. It tempers the acidity of citrus ingredients. That's also why Angostura aromatic bitters is known to settle the stomach. Angostura aromatic bitters are sodium and Gluten-Free.