The Hymn to Ninkasi is preserved on Old Babylonian tablets copied around 1800 BCE, in a Sumerian that was by then a learned language, and its composition is probably older than its manuscripts. It is a praise poem in the standard form, addressing the goddess in the second person stanza by stanza, and each stanza happens to describe one step of brewing. She is the one who handles the dough with a big shovel, who bakes the bappir twice, who soaks the malt in a jar and spreads it on the ground to sprout, who pours the filtered beer out like the Tigris and the Euphrates in flood.
It is often called the oldest surviving beer recipe, and that is half right. The sequence of operations is genuinely there and is genuinely informative, it is a principal source for how Sumerian beer was made, but it gives no quantities, no times and no temperatures, because it was never meant to instruct anyone. It works as a recipe for the same reason it works as a hymn: everyone hearing it already knew how beer was made, and the pleasure of the poem is in seeing familiar work described as the act of a god. Modern attempts to brew from it, including a well-publicised one by an American brewery with Assyriological advice in 1989, have had to supply from elsewhere everything the text leaves out.
The hymn survives alongside a companion drinking song, and the pair are among the more approachable pieces of Sumerian literature. Their appeal now is partly that they are unpretentious: no cosmogony, no kingship, no flood, just a goddess and a very good drink.