Turmeric has a peculiar fragrant, bitter, acrid odor and rich color. The rhizomes are boiled for several hours and then dried in hot ovens, after which they are ground into a deep orange-yellow powder commonly used as a spice in curries and other South Asian and Middle Eastern cuisine, for dyeing, and to impart color to mustard condiments. Its active ingredient is curcumin and it has an earthy, bitter, peppery flavor and a mustardy smell. It flavors potatoes, tea, eggs, fish, and pickled vegetables.