Angostura aromatic bitters contains no artificial colors, flavors, or additives. Its unique density, consistency, visual appeal, and flavor have withstood the test of time for nearly two centuries. The precise recipe is a closely-guarded secret, known in its entirety only by five individuals, with other staff only having knowledge of individual parts. Since 1824, the same recipe has been made by weighing and mixing a selection of herbs and spices, then pouring them into stainless steel baskets and introducing alcohol to the mix.