Indigo naturalis

Indigo powder can be used as a natural colouring agent in soaps to obtain magnificent blues ranging from blue-grey to light blue to dark blue. Soapmakers typically use between 1/2 and 1 1/2 tablespoons for 500 g of oils. For a more intense blue, mix the powder in the water-hydroxide mixture. For a lighter blue, mix the powder in a bit of oil before adding it to the trace. Please note: the colour will vary according to the oils and butters used.