Rasam has a distinct taste in comparison to sambar due to its own seasoning ingredients and is watery in consistency.

[2] An Anglo-Indian variety of rasam is the soup-like dish mulligatawny whose name is derived from the Tamil word mulagu thani.

In South Indian households rasam commonly refers to a soupy dish prepared with a sweet-sour stock made from either kokum or tamarind, along with tomato and lentil, added spices and garnish.

Rasam is prepared mainly with a tart base such as kokum, malabar tamarind (kudam puli), tamarind, vate huli (vate huli powder), ambula or amchur (dried green mango) stock depending on the region.

Jaggery, cumin, black pepper, turmeric, tomato, lemon, mustard seeds, chilli powder, curry leaves, garlic, shallots and coriander leaves may be used as flavoring ingredients and garnish in South India.