A gruit ale is a beer brewed with spices and herbs instead of hops. It is a beer time machine since it dates back to 700-1700 AD where hops were an unknown ingredient to beer brewing. When brewers began using hops, gruits lost a lot of appeal and faded away over time. Luckily with the emergence of craft breweries, some have brought this awesome style back from the dead!
For more informations, visit the official page of this event www.GruitDay.com