Vratya Stoma is a purificatory ritual during the Vedic age. According to Amarakosha, the word vratya means a twice-born, for whom the samskaras (purification rites), such as upanayana, have not been performed. So, a vratya is one who has lost his innate rights in his community by birth because of the absence of purification rituals that are mandatory. It is also possible that a twice born may become a vratya because of his bad conduct if he indulges in prohibited deeds such as adultery, murder, consumption of alcohol, etc. In order to regain one’s lost rights and to redeem oneself from the state of an outcaste, the Vratya Stoma rite has to be performed by the person concerned.
This ritual has been formulated by Apastamba in his Srauta Sutra. He gives many options for the conduct of the same. It is a one-day Soma ritual, as we find from the details coded in these sutras.
In Arsheyakalpa (Sama Veda), four types of Vratya Stoma are prescribed. In Asvalayana Srauta Sutra of the Rig Veda, we find seven on-day Soma rituals called Vratya Stoma.
It is not clear whether one has to perform Agnistoma – the first Soma Yajna – before one performs Vratya Stoma. But before one can venture to perform this ritual, one has to undergo the mandatory samskaras (purification rituals) for the first time or the second time, as the case may be, as one has to become a fit person for performing any ritual.