Read this in the list of known bug
Cannot complete The Case of the Missing Ale / world marker misplaced
Workaround – Finding the brew: The brew is located here. Spoilers.
Workaround – Handing over the brew to Ake: You have to hand over the brew here. Spoilers.
This, however, doesn't work for my boyfriend's game. I got mine to complete but the furthest he can get is the fist-fight with Ake. After that, he goes to where the ale is but it never glows blue. He can pick it up but if he goes to where Ake should be, Ake is never there.
The marker for where the ale is showed up the first time he tried it but he dropped the barrel when he walked across a stream that was just a little too deep.