The surā-beer: a barley beer, a millet beer, a rice beer or a mixed beer?
A 4th text integrated late in the Vedas, the Atharva-veda, contains the expression dhanya-rasa, "grain juice" (2.26.5). It underlines the importance of cereals in the economic and religious life of the classical period.
But which cereals are we talking about?
Before the arrival of the Ârya in the Indus basin, the region was a land of barley, wheat and millet. The composition of the surā beer reflects this technical and brewing tradition that the Ârya probably found on-site and integrated into what would become the Vedic culture. The division of roles between the two beverages, Soma and Surā, testifies to a cultural combination of pastoral and agricultural traditions and a religious syncretism.
Prayer for Food: "May Soma, we enjoy you; through the milk and barley stew, then Vatapi, you become fat" (RV I.87.9).
With the late Vedic texts, the same surā beer incorporates rice as a raw material. It is in the earliest texts brewed with malted barley (or malted paddy) + cooked rice + cooked millet. Later, it is described as being made with cooked raw barley (not malted) and cooked rice. The malting of barley (or millet) is no longer mentioned. A paste is then made with cooked rice and leguminous plants (beans) which is used as a support to cultivate hydrolysing moulds. They are brought by plants (roots or crushed stems) that are mixed with the cooked dough and molded into pellets or patties. These mycelium can saccharify the starch of the grains. Once these mycelia have developed sufficiently on their cooked starch substrate, the pellets are dried to be preserved and used when the time comes to brew beer. It is then sufficient to crush them to incorporate them into a cooked mass of rice, barley or millet grains. The cooked starch is quickly converted into sugars which ferment immediately. Amylolytic ferments also contain yeast or fungus mycelium that are able to convert sugars into ethanol. The amylolytic ferments simultaneously trigger the saccharification of the cooked starch and the alcoholic fermentation of the released sugars, two simultaneous biochemical processes in the semi-liquid mass of cooked starch. These amylolytic ferments are called nagnahu or māsara (Vedic texts), or later kinva (Arthasastra).
An important evolution of brewing techniques thus took place in northern India in the 1st millennium BC, seemingly in several stages :
1 - Malted or raw barley, wheat or millet based beers around 1500 BC. Inherited from the presumed brewing traditions of the Harappa and Mohenjo-daro cultures. Surā beer is named in the Rig-Veda, the oldest text of the Vedic tradition.
2 - Introduction of malted or simply cooked paddy rice in the composition of the surā beer (c. -1000).
3 - Introduction of amylolytic ferments (nagnahu, māsara?), a technique competing with malting to brew the surā beer.
4 - Brewing of surā beer with barley, millet and rice, but gradual disappearance of the barley or rice malting technique, except for brewing the surā beer for Vedic rituals such as the Kaukilī Sautrāmaṇī, the Caraka Sautrāmaṇī or the Rajasuya (royal enthronement). During the Maurya Empire (322-185 BCE), the Arthasastra mentions the kinva beer ferment , an offspring of the Vedic era nagnahu beer ferment, for brewing the traditional medaka, prasanna, svetasurā beers, and trading in them (Maurya empire : list and composition of 3 kinds of beers).
5 - Gradual fading of barley and millet in favour of rice for brewing traditional Indian beers (early AD). Our written sources originate exclusively from the Brahaman culture. The lifestyles of the non-Hindu indigenous ethnic groups elude us almost completely. They constitute the majority of the inhabitants of the Indian subcontinent and are its productive forces: farmers, fishermen, craftsmen, holders of technical know-how, etc. Indian ethnobotanists are nowadays trying to reconstruct these ancient brewing traditions with the help of the living skills of these North Indian ethnic groups.
6 - Rice as the sole grain for brewing beer in the irrigated plains of North India during modern times (subject to the above remark about ethnic groups and producing social classes).
Barley, millet and eleusine have been used as a brewing grain in the mountainous regions and Himalayan foothills since thousands of years. But like rice beers brewed in the great plains of India, they are brewed using the amylolytic fermentation technique, not malting.
The Sukla Yajur-veda (YV XIX. 13-15; 82-83) describes the preparation of two fermented beverages: the surā beer and the parisrut beer. The sura beer is made from germinated barley, paddy rice and cooked rice. The preparation of a leaven is mentionned to trigger the alcoholic fermentation.
The difficulty comes from the technical interpretation of the parisrut. In later Brahmanic texts, parisrut refers to the mass in a state of full and simultaneous saccharification-fermentation, enclosed in a pot and not yet completely diluted (surā and Brahmanism). Parisrut is not the filtered beverage, but the semi-liquid fermented mass that precedes it. In the Yajur-veda, one of the first three Vedic texts, what does Parisrut refer to? A beer distinct from beer-surā or one of its intermediate states, the fermented mash before its dilution with water?
The Katyayana Srauta sutra (XV, 9.28-30; XIX, 1-2) provides a complete recipe for brewing a surā-beer. Boiled rice and boiled barley (not malted) are mixed with a ferment and one ingredient called māsara. The whole is sealed in a jar, which is buried in a hole for three nights. The ferment used here is obviously of the amylolytic type. The technical role of the māsara is not clear (leavening? flavouring? both?).