Vista Brewing is one of the local breweries participating in a Texas Brewshed Alliance project highlighting the importance of water in the beer-making process. [Nell Carroll / AMERICAN-STATESMAN]

Although beer is made with four main ingredients, some of them — OK, all but one — are more obvious in the final product. Beer is primarily water, but the hops, malt and yeast are far more detectable. There's no doubt the water plays an important role nonetheless, and three Austin breweries intend to showcase just what that is with a series of experimental beers.

Vista Brewing, Real Ale Brewing and Black Star Co-op created the exact same beer using different water sources to see how the water affects the final flavor. The American lagers will be released at a few events starting this weekend at Craft Pride, where you'll be able to try them side by side. Vista's features the Trinity Aquifer water that goes into all of the Hill Country brewpub's beers, while Real Ale and Black Star used rainwater and City of Austin water, respectively.

And they expect each one will have subtle but noticeable differences.

"Our Well Head Lager is tasting awesome — light, clear and slightly sweet. I have a feeling all three will be great, and it will be interesting to do the side-by-side taste test," Vista co-owner Karen Killough said.

The three breweries have produced the beers in collaboration with the Texas Brewshed Alliance, an initiative of the Wimberley Valley Watershed Association that aims to bring water conservation issues to the forefront of beer lovers' minds through fun projects like this one.

"Brewers understand the value of water better than almost any other industry, I'd say," Texas Brewshed Alliance co-founder Tom Waymouth said this spring. "We're gathering brewers who really care about water. They are the perfect spokespeople to talk about it and drive home why people should care."

The Waters of Central Texas beer tasting at Craft Pride on Friday evening doubles as a fundraiser for the Texas Brewshed Alliance. Vista, Real Ale and Black Star will donate $1 from each pint of their respective lagers to the alliance, and Craft Pride will match those donations. Can't make that event? Black Star hosts one this evening to tap its lager, the Austin Underground, and Vista has one on Sept. 26 featuring its own, the Well Head.

The American lager style is "a clean and light beer which will highlight the role that water plays in the brewing process," according to the Facebook event post for Vista's beer release.

Another event where you'll be able to taste all of them side by side is Partners in Craft, held the night before the Texas Craft Brewers Festival on Sept. 27. Tickets are still available for $55.