I can't believe I've missed out on this before. Brewfest is being held for a fourth consecutive year out on Governor's Island June 19 from 3:30-8PM. The last three sold out according to the website, so don't get left out.
This festival is dedicated to craft beer (and cider) tasting and brewing, but there will be music and food as well as the chance to check out Governor's Island (I still haven't). And there will be seminars about brewing - yes you can make your own beer at home! Tickets are hardly free ($55 for the basic tasting pass), but there is a $25 music lover pass for the non-beer drinkers among us (that would include myself). No one under 21 will be admitted, so this is a situation where you get a sitter (who is probably under 21 too, so no conflict of interest there!).
http://www.nybrewfest.com/index.php to buy tickets.