The actor, who is due to marry Jolie in the coming days, apparently arrived at their rented mansion in Richmond at 6am after drinking with Guy Ritchie at his London pub The Punchbowl.
"Brad spent the evening boozing with Guy and other pals in Guy's pub," a source told the Daily Star.
"Ange was shocked he came home in such a state, especially as he hadn't called her. She said she hadn't seen him like that in years. Brad blamed it all on British beer.
"The group spent the night in the back room of the pub drinking real ales such as Bombardier and Spitfire. Brad sampled a few different beers and things got a bit rowdy. It was a rare chance for him to let his hair down."
Pitt was recently said to have congratulated ex-wife Jennifer Aniston on news of her engagement.