Spring in San Francisco means towering Easter Bonnets in Dolores Park, trashed Big Wheels on Potrero Hill, and the advent of the beer festival season. Here are two upcoming brewfests to help kickstart your spring:

Triple Rock 11th Annual Firkin Gravity Festival: This fest lets local breweries showcase their “real ales” while serving them from firkins. Real Ales are officially defined by the Campaign for Real Ale (CAMRA) as being unpasteurized, unfiltered, and naturally carbonated. The firkins they're served from are smaller than regular kegs and the cellar temperature suds they hold (50 to 55 degrees) are dispensed using either gravity or by being drawn out of them by beer engines. If all this sounds very old school, it is. That’s because all of the traditional beer styles were brewed to be served this way and for many beer lovers it’s the best way to appreciate the inherent qualities of fresh craft beer. If you haven’t had much experience with real cask ales, this is a great event to sample them.

Participating guest brewers include 21st Amendment, Bear Republic, Devil's Canyon, Drake's Brewing, Iron Springs, Magnolia, Marin Brewing, Peter B's, and Social Kitchen & Brewing.

It all takes place Saturday, April 13th from 11:30 am till the firkins run dry at Triple Rock Brewery & Alehouse in Berkeley. Twenty bucks gets you five 5-oz tastings and additional samples are $3 each.

The Bay Area Craft Beer Festival:This is the third annual Martinez beer fest, which seems to get bigger and better each year. The brewers' lineup for 2013 includes some relative newcomers such as Altamont Beerworks, Rocksteady Brewing and St. Florian’s Brewery.

The festival is held outside at the Martinez Waterfront Park in the city’s Historic Cannery District. In addition to beers from over thirty breweries, there’s live music and plenty of food options, both in the venue and outside in the downtown area. If the weather is right, this fest can make for a sweet afternoon scene, especially if you travel to it using Amtrak or BART. The Martinez Amtrak station is a short walk to the park, and for BART riders there are free shuttles to and from the North Concord station. Since this is Martinez, there’s plenty of free parking if you prefer to drive. Note: This event is for adults 21 and over.

Participating brewers include: