ale or wine infused with wormwood (and sometimes other botanicals)
A common, rudimentary, English digestive aid dating from the 1600s. Eventually streamlined into Richard Stoughton’s Elixir.
Archaic recipes exist for infusing ale or wine to produce a purl. Some may include ingredients now understood to be dangerous, so please exercise caution. For a modern, simple, flexible, and possibly more pleasing ersatz experience, simply doctor the ale or wine of your choice with the bitters of your choice.
Oxford Companion to Spirits and Cocktails, p. 565; barware icons courtesy of Haus Alpenz