PARIS, France (AFP) — A 600-year-old grape seed discovered in the toilets of a medieval French hospital is genetically identical to the grapes still being used to make pinot noir wine, scientists said Tuesday.

The seed reveals that people in France have been cultivating this immensely popular variety of grape since at least the 1400s, the scientists said in a new study.

The seed was found in a toilet in a 15th-century hospital in Valenciennes in northern France. At the time, toilets were sometimes used as rubbish bins, the researchers explained.

The study, which was published in the journal Nature Communications, involved sequencing the genome of 54 grape seeds dating from the Bronze Age — from around 2,300 BC — to the Middle Ages.