Boston Beer Co., the second largest craft beer in the U.S., and Delaware-based Dogfish Head Brewery announced a $300 million merger agreement Thursday in a major shakeup to the industry. 

The deal means Dogfish Head owners Sam and Mariah Calagione receive $128 million dollars in stock of the new combined company, as well as $173 million dollars in cash from Boston Beer, which sells the popular brand Samuel Adams.

"More than a dozen of our peers have sold to international conglomerates, others have come together through platforms bringing a handful craft breweries together in roll-ups," Sam and Mariah Calagione said in a statement about the merger. "While neither of these strategies appealed to us, we did realize that Dogfish Head would be a stronger company with the support of our friends at Boston Beer, and vice versa."

This deal will allow both companies to retain their status as craft breweries, which the U.S. Brewers Association defines as brewing less than six million bottles of beer annually and having less than 25 percent ownership by a "beverage alcohol industry member that is not itself a craft brewer."

"Our merger is different. This partnership provides an opportunity for us to join forces and successfully compete while retaining our position and leadership within the indie craft market" Boston Beer CEO Jim Koch said in a statement. "We'll have a balanced offering of lagers, IPAs, sours, hard seltzer, spirits, and teas that our consumers love and demand."

Along with Sam Adams, Boston Beer also has Twisted Tea, Angry Orchard ciders and Truly Spiked & Sparkling.

Dogfish, which has several varieties of India Pale Ales, is the 13th-largest craft brewery in the country.

Monday is the start of Craft Beer Week in the U.S. with events taking place across the country to celebrate the craft beer culture.

As of 2018, the U.S. Brewers Association estimates that there are at least 7,450 craft breweries across the country.