LAFAYETTE, La. — Matthew Tarver, then the trademark licensing manager at the University of Louisiana at Lafayette, was kicking around marketing possibilities with a colleague one day when a light bulb clicked on.

One of them said: beer!

The other replied: why not?

Now, more than four years after stumbling on an idea that now seems so obvious, Ragin’ Cajuns Genuine Louisiana Ale and its younger sibling, Ragin’ Cajuns Genuine Louisiana Lager, have put the school at the forefront of a burgeoning movement, with more than 20 universities marketing their own brand of beer.

They come with names like Boiler Black (Purdue), Old Tuffy (North Carolina State), El Lobo Rojo (New Mexico) and Stampede (Colorado).