Kalpasi is an unusual spice used in Maharashtrian and Tamil cooking.
Using Kalpasi in Indian Cooking
Kalpasi or 'Parmotrema perlatum' is also known as black stone flower or Darar da phool. It is an unusual spice and one that isn't used across the board in Indian food.
It is actually a species of lichen that can be purchased as a flaky, silvery, grey dried spice that looks like petals or dried paint. In specific dishes it is either used as a whole spice or as part of a spice mix. It is a key component of Goda masala which is used in lots of Maharashtrian cooking. It is also found in the Kala masala blend used in south Indian food. The spice is used in both meat dishes such as Nahari and Bombay biryani as well as in vegetarian dishes. Although it doesn't have a strong, distinct aromatic it is thought to give a wonderful earthy fresh flavour to masala sauces which is much loved in Tamil cuisine.
Very little is know about how it's produced as a food ingredient but we do know it is harvested or scraped from rocks and tree bark, so it's important to clean it before you use it.
For best results Kalpasi should be roasted in oil with other spices such as cassia bark, bay leaves and star anise to intensify the flavour it imparts into the dish.