Turmeric is the dried, ground rhizome of Curcuma longa, a leafy tropical relative of ginger whose brilliant orange-yellow flesh stains everything it touches and gives curry powder its colour. Cured and milled to a fine ochre powder, it smells warm, earthy and woody with a faint ginger-like sharpness and a mustardy, slightly bitter edge, and tastes musky and gently astringent rather than hot. It is the base note of countless South Asian masalas and the golden backbone of Indian, Thai and Persian cooking, and the same pigment that colours a dal also dyes monks' robes and turns prepared mustard bright yellow. Used by the pinch, it is more colour and depth than flavour — quietly bitter and aromatic, it rounds out a blend rather than dominating it.