Two 400-year-old bottles of wine, pulled from a shipwreck, will head to auction this week. But whoever makes the purchase may not want to open them.

Discovered by divers off the coast of Germany in 2010, the pair is believed to date back to the 17th century, although experts aren’t certain of the exact year.

Christie’s, who will wield the gavel this Wednesday and Thursday in London, says the set are the oldest bottles they’ve ever brought to market.

Buy buyer beware. The auction house admits the lack of fortifying preservation makes their drinkability “questionable,” so the bottles are instead offered for their “historical and vinous importance.”