Sometimes it's so hot out that all you can crave are the crisp, clean flavors of the lightest of ales. Learn to brew your own on Sunday, when Walrus (470G 49th St., Oakland) hosts a summer-beer-making class for everyone from total noobs to more experienced brewers. Instructors Hillary Huffard and Luke Janson -- who have brewed more than 120 original recipes on their East Oakland urban farm -- will teach the ins and outs of brewing chemistry, explain what specifically makes a good summer beer, and lead you in the hands-on process of brewing your own. On top of getting a lunch provided by Doña Tomas, you'll take home your own fermentor filled with your personally concocted summery brew. Cheers to that.