Wired has an article about the resurrection of a 2,550 year-old beer recipe.
Six specially constructed ditches previously excavated at Eberdingen-Hochdorf a 2,550-year-old Celtic settlement, were used to make high-quality barley malt, a key beer ingredient, says archaeobotanist Hans-Peter Stika of the University of Hohenheim in Stuttgart. Thousands of charred barley grains unearthed in the ditches about a decade ago came from a large malt-making enterprise.
Stika published his findings in Archaeological and Anthropological Sciences, where you can find the original paper.