 All four studies concluded that darker liquors, which have higher congeners, produced worse hangovers.One even showed that hangovers were worse "and" more frequent with darker liquors.In a 2006 study, an average of 14 standard drinks (330 ml each) of beer was needed to produce a hangover, but only 7 to 8 drinks was required for wine or liquor (note that one standard drink has the same amount of alcohol regardless of type).