Boston-based The Boston Beer Co. Inc. and Dogfish Head Brewery announced that the companies have signed a definitive merger agreement, bringing together two pioneering independent craft breweries.

Together, Boston Beer and Dogfish Head will create a powerful American-owned platform for craft beer and beyond, the companies says. Following the transaction, the combined company will have a leading position in the high end of the U.S. beer market, bringing together Boston Beer’s craft beer portfolio with Dogfish Head’s award-winning portfolio of IPA and session sour brands.

This combination also brings together two of the leading founder-brewers in the United States — Jim Koch of Boston Beer and Sam Calagione of Dogfish Head — both of whom will continue to lead brewing innovation for the newly combined company. Sam and Mariah Calagione, Dogfish Head’s two co-founders, have elected to take substantially all of their merger consideration in the form of SAM stock and collectively will become the largest non-institutional shareholders after Jim Koch following the close of the transaction. Sam Calagione will join Boston Beer’s Board of Directors and Dogfish Head’s band of off-centered co-workers will join the Boston Beer team and continue to heavily be involved in beer and “beyond-beer” projects, as the companies expand opportunities for future innovation, the companies say.

“We believe we are creating the most dynamic and diverse American-owned platform for craft beer and beyond,” said Koch, founder and chairman of The Boston Beer Co., in a statement. “Dogfish Head has a proud history as a craft beer pioneer with a brand that is beloved by American consumers and highly respected by the industry. Sam and I have stood shoulder-to-shoulder in some of the defining efforts in craft brewing including the creation of the Brewers Association, the craft beer definition, the craft brewer seal and the creation of the SAVOR food and beer event. This combination is the right fit as both Boston Beer and Dogfish Head have a passion for brewing and innovation, we share the same values and we will learn a lot from each other as we continue to invest in the high-end beer category. I am very happy that Sam will join the Board of Directors at Boston Beer. He is a tremendous friend, innovator and brewer, and I could not be more excited to work together with him for many years to come.”

Calagione, founder and brewer of Dogfish Head, added: “Not only are Dogfish Head and Boston Beer two original American breweries, but Jim Koch and I worked hard with other leading craft brewery founders and the Brewers Association to develop and champion what defines independent American brewers. This merger better positions Dogfish Head and our co-workers to continue growing within this definition for many years to come. In fact, Mariah and I believe so much in the future of our merged companies that we are all in, and personally we’re reinvesting nearly all of the proceeds back into the combined entity. We’re also proud to announce that we intend to devote a percentage of the Boston Beer stock that we receive to establishing a foundation and funding various local charitable programs.”

The transaction is expected to close late in the second quarter of 2019, subject to customary closing conditions. Calagione and his family will receive approximately 406,000 shares of Boston Beer stock based on a share price of $314.60. Dogfish Head shareholders also will receive $173 million in cash, most all of which is for the benefit of Dogfish Head’s financial investors, with the exception of certain transaction-related expenses.

Dogfish Head is on pace to sell nearly 300 thousand barrels for the full year 2019, which would represent high single-digit growth versus the prior full year. Net sales for the full year 2019 are expected to be between $110 and $120 million. Dogfish Head employs approximately 400 employees, produces most of its beer at its brewery in Milton, Del., and sells its beer in more than 40 states. Boston Beer plans to consolidate Dogfish Head results into Boston Beer’s financial results beginning late in the second quarter of 2019 and Boston Beer currently estimates that the transaction will be neutral to slightly accretive in 2019 and will not have a material impact on full-year 2019 earnings per diluted share. BI