Thippili or long pepper is a common spice used in Ayurveda for the cure of many ailments. This belongs to the same family as black pepper and is used in Indian cooking as it is known for its treatment of cough, cold, digestion problems, removing toxins, digestive issues among others.
This rasam is a personal favourite and the spice of the thippili can be felt in every sip. The fruit of the long pepper plant is called arisi thippili and the bark/roots are called kanda thippili. Both have medicinal properties and are used to make the rasam.