Black Turmeric is called as Curcuma Caesia or Black Zedoary.
The cultivation and harvest practices are similar to that of common turmeric. In the fields, the rhizomes are washed thoroughly and are placed in a wide mouthed cauldron. The water is poured in the cauldron such that the rhizomes are completely covered. The cauldron is covered with a lid, and the rhizomes are boiled for about 30 minutes until foam oozes out with a strong odour. The rhizomes are taken out when the water is reduced to one-third of the original and they are soft and their inner portion has turned from blue to dark or pale brown. The rhizomes are then dried in hot sun for 10 to 15 days until hardened. These dried rhizomes are then packed for marketing.