The Soma Problem: What Did the Vedic Poets Actually Drink?

A plant that swallowed an entire book

Somewhere around 1200 BCE, give or take a century, a poet of the Bharadvāja clan sat down (or more likely stood before a fire) and sang about the moment when stones crush a tawny stalk and its juice runs through a woollen filter into a wooden vat. The juice was mixed with milk, offered to Indra, and drunk by the priests. The poet called it soma (सोम), and he was not alone in his enthusiasm: Mandala 9 of the Rigveda, all 114 hymns of it, is devoted to this single substance. No other entity in the text receives a full book. Indra, with roughly 250 hymns scattered across all ten Maṇḍalas, is praised more often, but his hymns share shelf space. Soma gets a room of its own.

The reasons are partly liturgical. The hymns of Mandala 9 are pavamāna hymns, “purification songs,” chanted during the actual pressing and filtering of the plant at the morning, midday and evening pressings of the Soma sacrifice. They are performance texts: the words accompany the physical act. When RV 9.1.1 opens with svādíṣṭhayā mádișṭhayā / pavásva soma dhā́rayā (“Flow, Soma, in the sweetest, most exhilarating stream”), the verb pavásva (“flow, be purified”) is both a prayer and a stage direction. The juice is flowing while the poet sings. The entire Maṇḍala is, in effect, a soundtrack to a biochemical process.

The trouble is that no one alive knows what the plant was. The Soma sacrifice fell out of regular practice sometime in the first millennium BCE, and the botanical identity was already a matter of speculation by the time the Brāhmaṇa commentators got to work. What followed, from the 1780s when European scholars first read the Rigveda to the present day, is one of the longest-running identification puzzles in the history of botany, pharmacology and philology. The debate has attracted mycologists, archaeologists, Iran specialists, chemists and at least one banker (R. Gordon Wasson, vice-president of J.P. Morgan). The candidates range from a red-capped fly agaric mushroom to Syrian rue to the Ephedra bush to cannabis. None has won consensus. The hymns remain the primary evidence, and they are stubbornly ambiguous: detailed enough to rule out some plants, not detailed enough to confirm one.

This article lays out the evidence.

What the hymns actually describe

Before evaluating candidates, we should let the text speak. The Pavamāna hymns repeat a set of physical actions with remarkable consistency. A reader who works through all 114 hymns of Mandala 9 will encounter the same preparation sequence, described from different angles, dozens of times.

The preparation sequence

Several physical characteristics appear repeatedly:

• Colour: hari (tawny, golden-brown) is the most common epithet. Also aruṇá (ruddy, reddish). Never blue, never white, never green.
• Stalks or shoots: the plant has aṃśú (shoots, stalks) that yield juice when crushed. This is one of the strongest constraints: the substance is not a cap or root but a stalk.
• Mountain origin: Soma is said to grow on mountains (párvatā, mū́javat). RV 10.34.1 names Mūjavat as the mountain of Soma; RV 9.46.1 calls it giríṣṭhā (“mountain-dwelling”).
• Loudness of pressing: the sound of the stones is a key motif, compared to bulls bellowing, thunder, and roaring rivers.

The tawny one, beautifully adorned, bellows as he enters the filter. He clothes himself in the waters, in the milk; he sits in the wooden vessels as a hawk on the seat.

(RV 9.3.1, after Jamison and Brereton)

The fingers press him forth, the ten sisters; they drive the golden-hued one through the sieve of sheep’s wool.

(RV 9.16.2, after Jamison and Brereton)

The “ten sisters” here are the ten fingers of the presser. The image is both literal and ritual: the priestly hands are doing physical work, and the hymn names the work while it is happening.

Aside. The woollen filter (pavitra) is not an incidental detail. Wool would catch fibrous plant material while letting liquid through. If the original Soma plant produced a viscous juice, wool is a sensible technology. The word pavamāna, which names the entire hymn-collection, is the present participle of √pū, “to purify”: Soma-who-is-being-purified. The filter is not accessory; it is the identity of the hymn genre.

flowchart LR
    A["Mountain-gathered<br/>plant material<br/>(aṃśú / stalks)"] --> B["Soaked in water<br/>(āpyāyana)"]
    B --> C["Pressed with stones<br/>(grāvan)<br/>🔊 Loud sound"]
    C --> D["Filtered through<br/>wool sieve<br/>(pavitra)"]
    D --> E["Mixed with<br/>cow's milk<br/>(gavāśir)"]
    E --> F["Offered to fire<br/>& drunk by priests"]
    style A fill:#d4a574,color:#000
    style D fill:#f5f0e1,color:#000
    style F fill:#c9463d,color:#fff

The experiential effects

The hymns describe what happens after drinking. The vocabulary clusters around a few themes:

The most famous experiential verse in the entire corpus is RV 8.48.3, not from Mandala 9 but from a hymn to Soma by the Kāṇva family:

We have drunk Soma; we have become immortal; we have gone to the light; we have found the gods. What can hostility do to us now, and what the malice of a mortal, O immortal one?

(RV 8.48.3, after Jamison and Brereton)

This is not a philosophical metaphor. Or rather, it may be, but it reads as first-person pharmacological testimony. The speaker has ingested something and reports, in present tense, that he feels immortal and luminous. The question for the botanist is simple: what produces that state?

The candidates

1. Amanita muscaria: Wasson’s mushroom hypothesis (1968)

R. Gordon Wasson, an amateur ethnomycologist who had already made his reputation with a 1957 Life magazine article on Mexican psilocybe mushrooms, published Soma: Divine Mushroom of Immortality in 1968. [1] His argument ran on several tracks:

• Colour: Amanita muscaria (fly agaric) has a bright red to orange cap, consistent with hari and aruṇá.
• Urine recycling: a notorious property of fly agaric is that the psychoactive compounds (muscimol, ibotenic acid) pass through the body largely unmetabolised. In Siberian shamanic traditions, the urine of a fly-agaric consumer is drunk by others for its effects. Wasson argued that RV 9.74 alludes to ritual urine-drinking.
• No root, no seed, no flower: Wasson noted that the Rigveda never mentions Soma’s root, seed, leaf, blossom or fruit, consistent with a fungus.
• Mountain habitat: Amanita muscaria grows under birch and pine at elevation, matching the Vedic claim of mountain origin.

The Wasson hypothesis was enormously influential. Wendy Doniger wrote an extensive companion essay in the same volume. [2] But the philological critiques were immediate and sharp. John Brough’s 1971 review in the Bulletin of the School of Oriental and African Studies pointed out that the hymns repeatedly describe pressing stalks (aṃśú), that the juice flows in streams, and that the preparation is noisy and laborious; none of this fits a soft, low-liquid mushroom. [3] Brough also challenged the urine-drinking reading of RV 9.74, arguing that the passage refers to rain flowing through the cloud, not urine through the body.

Aside. Wasson was not a Sanskritist. He relied on Karl Friedrich Geldner’s German translation and on Doniger’s readings. His strength was cross-cultural mycology; his weakness was that he could not read the primary text. This matters because many of the “fits” in his argument depend on selective translation. The word aṃśú, for instance, is unambiguously “stalk” or “shoot” in Vedic usage, and it is what gets pressed. A mushroom stalk is not a stalk in the Vedic sense.

2. Peganum harmala: the harmal hypothesis (Flattery and Schwartz, 1989)

David Stophlet Flattery and Martin Schwartz shifted the frame in Haoma and Harmaline (1989). [4] They began not with the Rigveda but with the Avestan Yasna, the parallel Iranian text, and argued that haoma (the Avestan cognate of Soma) was Peganum harmala, Syrian rue, a shrub native to the Central Asian steppe from Iran to western China.

The pharmacological case: Peganum harmala seeds contain harmaline and harmine, both β-carboline alkaloids that are potent monoamine oxidase inhibitors (MAOIs). On their own, harmaline produces visual disturbances, tremor and nausea. Combined with a tryptamine source (as in South American ayahuasca), MAOIs enable powerful psychedelic effects. Flattery argued that haoma/soma was harmal used in combination with another plant.

The major objection, raised by Harry Falk and others, is that the Rigveda never describes two plants being combined. The preparation is simple: one plant, stones, water, wool, milk. If Soma required an admixture plant for its psychoactive effects, the texts are silent about it, which seems unlikely given the obsessive ritual detail of the Pavamāna hymns. [5]

3. Ephedra: the steppe candidate (Falk 1989; Sarianidi 2003)

Harry Falk, in a 1989 article, and later scholars working on the Bactria-Margiana Archaeological Complex (BMAC) proposed Ephedra as the most plausible candidate. [5] Victor Sarianidi’s excavations at Gonur Depe in Turkmenistan (1990s-2000s) found botanical residues in temple rooms that he identified as Ephedra, cannabis and poppy, apparently mixed in ritual vessels. [6]

The case for Ephedra:

• Stalks: Ephedra species are jointed shrubs with prominent green stems and no true leaves. The stems are exactly the kind of thing you would press with stones: fibrous, yielding a bitter juice. The word aṃśú fits.
• Mountain origin: Ephedra species (E. intermedia, E. major) grow widely across the mountains of Central Asia, the Hindu Kush and the western Himalayas.
• Stone pressing: the fibrous stems require real force to extract liquid. The noise of stone-pressing makes mechanical sense.
• Wool filtration: the stringy, fibrous residue of crushed Ephedra stems would naturally need filtering through wool.
• Chemistry: Ephedra contains ephedrine and pseudoephedrine, sympathomimetic amines that produce alertness, energy, elevated heart rate and a sense of physical power. The effect profile is stimulant, not hallucinogenic.

The principal weakness of the Ephedra hypothesis is pharmacological. Ephedrine makes you alert and energetic; it does not make you feel immortal, see the gods, or experience the kind of overwhelming mada (“intoxication, rapture”) the hymns describe. Several scholars, including George Thompson (1995) and Matthew Clark (2017), have argued that the Vedic descriptions suggest a stronger psychoactive than a stimulant. [7] [8]

Sarianidi’s BMAC findings are suggestive but contested. The identification of the plant residues has been challenged, and the BMAC sites are geographically and culturally adjacent to, but not identical with, the Vedic world. Still, the BMAC evidence is the closest thing we have to an archaeological data point.

4. Cannabis, mixed-plant theories, and other proposals

Several scholars have proposed Cannabis sativa (Saryanidi found cannabis residues at Gonur Depe alongside Ephedra and poppy). [6] Cannabis has a long history in South Asian ritual and medicine. The problem is that the Rigvedic preparation does not match cannabis use: you do not typically press cannabis stalks with stones to extract juice, and the hymns never mention burning or smoking, which is how cannabis is most commonly consumed for psychoactive effect. The later Atharvavedic bhang tradition involves an infusion, not a pressing.

Frits Staal (2001) proposed that Soma may not have been a single plant but a ritual category that could be filled by different species depending on what was locally available. [9] This would explain why the tradition survived the plant’s disappearance: when the original Soma became unavailable (perhaps as the Vedic people moved from the mountains into the Punjab plains), substitutes were employed. The Śrauta Sūtras indeed list substitute plants (pratinidhi), including pūtīka (a species of Sarcostemma or Periploca). By the medieval period, the default “soma” in South Indian Śrauta rituals was a creeper with no significant psychoactive properties.

The Avestan parallel: Haoma

The Avestan Yasna (chapters 9-11, the Hōm Yašt) describes a plant called haoma that is linguistically cognate with Soma (both derive from Proto-Indo-Iranian *sauma-, from the root *sau-, “to press”). [10] The Avestan descriptions parallel the Vedic ones closely:

• Haoma is pressed (hunāmi, cognate with Vedic sunóti)
• Haoma is golden or tawny (zairi-)
• Haoma grows on mountains
• Haoma grants vigour, health and spiritual insight

The Avestan text provides one detail the Rigveda lacks: Yasna 10.12 says haoma grows “on many mountains, on the many distant heights,” and later Pahlavi commentary identifies it with a plant growing in the Alborz range. Modern Zoroastrian ritual uses Ephedra (in Iranian Zoroastrian practice) or pomegranate twigs (in Parsi practice) as the haoma plant. [11]

Henrik Samuel Nyberg (1995) argued that the Avestan evidence strongly supports the Ephedra identification, since Ephedra is the plant actually used in surviving Iranian haoma ceremonies. [12] The counter-argument is that the modern ritual plant may itself be a substitute; the living tradition does not guarantee continuity of species.

He, the golden-hued, pressed by the stones, mixed with the milk of cows, Soma the exhilarating, has flowed into the filter as a river into a lake.

(RV 9.86.32, after Jamison and Brereton)

The comparative evidence is useful but not decisive. What it does establish is that the Soma/Haoma tradition predates the split between Indo-Aryan and Iranian peoples, placing it firmly in the second millennium BCE and in a geography that includes the mountains of Central Asia. Both branches independently preserved the ritual act of pressing a mountain plant with stones, mixing it with dairy, and consuming it in a religious setting.

Why 114 hymns?

A question worth asking: why does an entire Maṇḍala exist for one plant?

The answer lies in the structure of the Soma sacrifice itself. The agniṣṭoma (“praise of Agni”), the paradigmatic Soma rite described in the Śrauta Sūtras, is a multi-day affair with three pressings per day (morning, midday, evening). At each pressing, a specific sequence of Pavamāna hymns is chanted. The hymns are not interchangeable: particular ones are assigned to particular liturgical moments. [13]

Mandala 9 is, in this sense, a liturgical handbook arranged by metre. The hymns in Gāyatrī metre come first; those in Jagatī come later; those in mixed metres close the collection. Bergaigne (1878-1883) and more recently Oldenberg demonstrated that the arrangement follows a functional logic tied to the ritual sequence. [14] [15] Each hymn was composed for a moment in the pressing, and 114 of them accumulated because the ritual was performed frequently and different priestly families composed their own versions.

The sheer volume of Soma poetry also tells us something about the plant’s cultural centrality. Fire (agni) is the mediator; Soma is the substance that makes the sacrifice work. As RV 9.96 puts it, Soma “brings the gods together,” functioning as the material link between human ritual and divine presence. (For more on Agni’s parallel centrality, see our discussion of fire as the cosmic priest.)

A decision framework

Given the evidence, here is how the major candidates fare against the textual constraints:

flowchart TD
    Q1{"Does the candidate<br/>have pressable stalks<br/>(aṃśú)?"}
    Q1 -- No --> OUT1["❌ Amanita muscaria<br/>(mushroom: no stalks<br/>worth pressing)"]
    Q1 -- Yes --> Q2{"Does pressing with<br/>stones yield flowing<br/>juice?"}
    Q2 -- No --> OUT2["❌ Cannabis<br/>(dry herb,<br/>no juice)"]
    Q2 -- Yes --> Q3{"Does it grow<br/>on mountains?"}
    Q3 -- No --> OUT3["⚠️ Peganum harmala<br/>(mostly arid lowlands,<br/>some foothills)"]
    Q3 -- Yes --> Q4{"Does the juice<br/>match 'hari' /<br/>tawny-gold colour?"}
    Q4 -- Partially --> OUT4["✅ Ephedra<br/>(best overall fit<br/>but weak on<br/>psychoactive intensity)"]
    Q4 -- No --> OUT5["⚠️ Other candidates"]
    style OUT1 fill:#f4cccc,color:#000
    style OUT2 fill:#f4cccc,color:#000
    style OUT3 fill:#fff2cc,color:#000
    style OUT4 fill:#d9ead3,color:#000
    style OUT5 fill:#fff2cc,color:#000

The chemistry, briefly

For readers who want the pharmacology:

The pharmacological gap between what Ephedra does (stimulation) and what the hymns describe (a sense of immortality, divine communion, overwhelming rapture) has led some scholars, including Clark (2017), to propose that the original Soma was a combination: perhaps Ephedra plus a psychoactive admixture that was either unnamed or referred to obliquely. [8] This is speculative, but it does address the two strongest objections to the Ephedra-only theory.

What we can say and what we cannot

Six observations seem defensible:

1. Soma was a real plant, not a metaphor. The preparation details are too specific and too consistent across dozens of hymns to be purely symbolic. You do not describe ten fingers pressing through wool unless someone is actually pressing something through wool.

2. It had stalks (aṃśú) that yielded juice when crushed with stones. This eliminates most fungi and dried herbs.

3. It grew on mountains. Multiple hymns, across different Maṇḍalas and different poetic families, agree on this.

4. It was mixed with milk, probably to moderate bitterness. Many alkaloid-containing plants taste harsh; dairy fats can mask this.

5. It produced powerful psychoactive effects: exhilaration, perceived strength, a sense of contact with the divine. These are described in first person.

6. The plant became unavailable at some point in the first millennium BCE, likely as the Vedic people moved east into the Gangetic plain, away from the mountain habitat. Substitutes were codified in the ritual texts.

What we cannot say, with current evidence, is which plant satisfied all six criteria simultaneously. Ephedra is the best fit on morphological and preparative grounds; it is the weakest on pharmacological grounds. Amanita muscaria fits the experiential description better but fails the physical preparation test almost completely.

The honest position, which Brough took in 1971 and which Jamison and Brereton adopt in their 2014 translation, is that the identification remains unresolved. [3] [16]

Reading recommendations

For those who want to go deeper:

• Start with the hymns. Read Mandala 9 in the Jamison and Brereton translation. Even ten hymns will give you the physical vocabulary.
• Wasson’s book is beautifully produced and worth reading for the argument’s ambition, even though the thesis has not held up. [1]
• Brough’s review (1971) is the single best critical demolition. [3]
• Flattery and Schwartz (1989) is essential for the Iranian side. [4]
• Falk’s 1989 article is short, clear and empirically grounded. [5]
• Clark’s The Tawny One (2017) is the most recent comprehensive survey of the entire debate. [8]

The hymns of Mandala 9 remain some of the most extraordinary religious poetry in any tradition: 114 songs about a golden juice flowing through sheep’s wool, carrying with it the entire relationship between human beings and whatever they called divine. The plant may be lost. The poems are not.

For the broader natural world of the Rigveda, including its rivers, fire-science and astronomical observations, see What the Rigveda Says About Nature and Vedic Astronomy and the Nakṣatra Calendar.