The following except is lifted from Kali Kaula by Jan Fries. Check it out on Amazon.

"Vedic religion was shaped by drugs. The early seers celebrated a deity called Soma who was identified with the moon and with a powerful intoxicating drink. Soma, they chanted, is the tawny bull of heaven, the steer, the eagle in the sky.  On flows the potent juice, sustainer of the heavens, the strength of Gods, whom men must hail with shouts of joy.  (Source: Rg Veda, the earliest Veda) Soma gave blessings and abundance, fertility to cattle, success in war, riches for the nobles, and gladness to the seers. The gods themselves feasted on Soma, who was their source and joy: Soma, thundering, hath produced the gods. (Source: Rg Veda)  Ingestion of Soma formed a vital part of the greater sacrifices and influenced the minds of those who ‘saw’ the proper rituals and ‘heard’ the true chants and sound vibrations. Indeed, Soma made the seers. The god was called Pavamana, the Self-Purifying, and his sweet, ambrosial juice amrta, ‘death-less’ (undying), the elixir of life. A good many of the early rites were received (or invented) by seers who were, we might imagine, spaced out of their minds. When we want to understand this sacrament, we encounter difficulties. The seers composed a large number of hymns to celebrate Soma, the Rg Veda contains roughly 120 of them, most of them in the 9th book, which is almost exclusively dedicated to the deity. Only Indra and Agni have more hymns, the majority of Vedic deities have to make do with half a dozen hymns or less. Soma constantly comes up when Indra the Thunderer is lauded, evidently, the rites were celebrated with his blessings. The soma rites were the most important sacrifices of the entire Vedic period. In Soma we encounter the first panacea, the first elixir of immortality of Indian lore. This idea survived long after the secret of Soma was forgotten. Now the seers were quite aware that, no matter how much Soma they consumed, their bodies did eventually grow old and die. In Vedic lore, as in later traditions, ‘immortality’ is a general idea meaning ‘great age’, the preferred optimum being a hundred years. The only real immortality that Soma could guarantee was an immortality of consciousness, which left the body at death and departed to Indra’s Heaven for an eternity of joy and revelry. Reincarnation wasn’t invented (or discovered) yet.

Things become complicated when we wish to work out what sort of plant Soma was and how it was prepared. The soma rites incorporated a wide range of ritual activities. They were not performed frequently, and the use of the drug was restricted to the Brahmins who performed the ceremonies. Not even the kings and nobles, the only people able to afford proper sacrifices, were permitted to taste Soma. Instead, they were offered a substitute. Each Soma ritual began with the preparation of the drug. This was an immensely complicated affair requiring days sometimes weeks of preliminaries. Even the pressing of the Soma sap took two to twelve days of continuous ceremony, followed by another twelve days of sacrifices. Animals were slaughtered almost continuously and each stage of the rite was accompanied by the singing and recitation of hymns. The Soma rites were all-round ceremonies involving a wide range of ritual activities. They exalted the sacrifice (the noble who paid for the event) to almost divine status and provided blessings for the entire community. The greater rites involved numerous acts of dedication, purification, elaborate baths, oracles, preparations of ritual space, dances, a symbolic fight between an Aryan and a dark Sudra, ritual arguing between a scholar and a prostitute, public coitus performed by a native couple, shooting arrows to ward off evil influences, song, music, and any amount of feasting. The priests had a strict hierarchy and there was an elaborate ritual schedule that had to be followed perfectly. Each hymn had a specific form of recitation and was divided into segments that required specific metric forms, intonation, and singers of a specific rank. Here we encounter the first bijas (seed-syllables) and ‘holy words’, such as Om and Hum, useful for general purposes, and specific terms such as His, to invoke rain, and Urj to ask for food or power. As the Soma rites are amazingly complex I can’t even offer a crude outline. It would take several hundred pages to give all the references and to sum up the procedure. For a readably brief account, see Die Religionen Indiens I by Jan Gonda (1960: 149-162). The Soma hymns are full of riddles. We read that Soma was pressed by ten sisters clothed in gold. In plain reality, the ten sisters were the ten fingers, each wearing a golden ring. Such metaphors are all too common. Over the last century, many scholars have argued what sort of plant Soma may have been. Soma was born on Mountains and hills. It was gathered, ritually ‘bought’ – the seller being ritually beaten up in the process – and driven to the ritual space on a chariot, celebrated like a king. The stalks were crushed between boards or in a mortar, pressed between sacred stones, the sap was filtered in a sieve, poured into water and strained through a woolen cloth, It was mixed with the milk and curds of several sorts of cows and consumed according to elaborate regulations. Most hymns insist that the pure juice, as it comes flowing through the sieve is brown, hence the need to pay for it (symbolically) with a brown cow. Other hymns call it tawny, yellow, gold, occasionally red and sometimes green. Soma was brilliant, clear, radiant, foamed, and tasted sweet.

One plant that may have been Soma is the fly agaric (Amanita muscaria), as mushroom pioneer R. Gordon Wasson proposed in 1962. Fly agarics are highly hallucinogenic when prepared properly. The mushroom has to be heated before ingestion, be it by drying in strong sunlight, over a fire, or by cooking, to transform the ibotenic acid, a slightly psychoactive but very disagreeable substance, into the five times more psychoactive muscimol. Raw fly agaric is well known to induce stomach cramps, nausea, vomiting, diarrhea, and other unpleasant experiences, and can even be fatal (Stafford 1977, R Schultes and A. Hofmann 1979, Alberts and Mullen 2000). In Siberia, people on fly agaric used to collect their urine as it contained almost all of the psychoactive substances ingested earlier. Some fly agaric was recycled up to six times while losing little of its potency. There is a reference to urine-drinking in the RG Veda. The heating is strangely absent in the Rg Veda. There is just one hymn, 9, 46, 4 stating Deft-handed men, run hither, seize the brilliant juices blent with meal, and cook with milk the gladdening draught.  What speaks against the identification of Soma with fly agaric are the varied colors of the sap, which suggest that we are not talking about any single plant or fungus, and the frequent statement that Soma tastes sweet. For more than a century, scholars have been searching for ‘the’ Soma plant. More than a hundred psychoactive plants have been proposed. One candidate, wild rue (Peganum harmala), may have been the old Persian wonder drug Haoma, a word that is related to the term Soma. Wild rue is mildly hallucinogenic, increases the effects of other drugs, but produces unpleasant side effects such as vomiting, nausea and, in overdoses, paralysis of the central nervous system. The plant is usually burned as an incense, not digested, this continues to this day among the Parsian Hunza people. Other drugs that may or may not have been Soma are given by Christian Ratsch (1988), who suggests that Soma may have been a general term for a group of psychoactive plants. Which could explain the contradictions in the hymns. That plant lore was highly developed can be seen in the Atharva Veda, a work that attributes the most amazing powers of healing and sorcery to a wide range of plants. Some of them were venerated much like deities. The Soma rites eventually lost importance. Wasson proposed that this happened as the Aryan tribes moved further from the cold mountain forests of the Himalayas, where fly agaric grows in the company of birch, spruce and pine. I doubt this. The conquest of India started with the warm and flat riverlands of the Panjab. Settling in the country, seers made Soma, and proceeded to do so for several centuries while they moved across India. In the late Vedic period, the sacrifices became smaller and cheaper, and when we enter the Upanisadic period, around 700 BCE, the importance of drugged exhilaration had greatly declined. Instead, we observe an increase in the methods that were to become early yoga. The seers of the Upanisads cared little for sacrifices, drugs, and ritual and began to seek the divine by fasting, tapas, breathing exercises, isolation, and various forms of meditation."