The Davis Beer Festival, also known as the Beer Fest or Brew Fest, is an annual event in early June at Sudwerk. It is put on by Citizens Who Care and all proceeds go toward that organization. The event features a boatload of breweries from the region (and some from far and wide) , live music, brewery tours, food, raffles, and so on. The first Beer Fest was held in 2007.
The fifth annual BeerFest is on June 4 from 1pm-5pm. It will feature more than 30 breweries and more than 100 beers to taste. Admission is $35 in advance or $40 at the door ($10 for designated drivers).
The fourth annual BeerFest was on June 5, 2010. They had a great turnout—see details here.