Arrowroot

Arrowroot is a fine, pure white starch milled from the rhizome of the tropical herb Maranta arundinacea, prized as one of the cleanest and most easily digested of all cooking starches. The plant is a leafy West Indian perennial whose pale, fleshy, scale-jointed underground stems are dug, washed, rasped and washed again until nothing is left but a snow-white powder of almost flavourless starch. Used as a thickener it has a particular virtue: it sets sauces, glazes and fruit fillings into a clear, glossy, odourless gel rather than the cloudy paste that flour or cornflour give, and it bakes into pale, tender, melt-in-the-mouth biscuits.