Boston Beer’s Truly Hard Seltzer.
Boston Beer’s Truly Hard Seltzer.

Distribution of Boston Beer Co.’s Truly Hard Seltzer, not its flagship Sam Adams offerings, have helped send the company’s shares to record highs this month, according to Macquarie analysts.

IRI market research data show a 21 percent increase in second-quarter shipments for the Sam Adams brewer, almost double Macquarie’s expectations.

‘‘It is hard to know just how high shipments will actually be’’ for its hard seltzer, analyst Caroline Levy wrote, given that Boston Beer over-shipped the seltzer to ‘‘ensure adequate distributor inventories for the summer selling season.’’

Investor optimism on the growing sales potential for Truly Hard Seltzer, paired with Boston Beer’s plans to buy Dogfish Head Brewery in a $300 million deal, vaulted shares to a record high earlier this month.


The brewer’s stock is up more than 60 percent year-to-date.

Second-quarter sales of the bubbly drink that has taken beach and pool parties by storm grew by 163 percent, while sales of Boston Beer’s Twisted Tea grew 22 percent, Levy wrote, citing IRI data, which helped cover a soft launch of the company’s Angry Orchard Rose and declining sales of beer.

Sales of Truly and Sam Adams’ nonbeer drinks account for more than three-quarters of sales, Levy noted, with further growth likely for Truly Hard Seltzer if it can follow the trajectory set by other beverages, including Twisted Tea and Diageo PLC’s Smirnoff Ice. The spiked seltzer industry also fits nicely as gluten-fee offering, with Angry Orchard Cider having the potential to be a ‘‘cash cow’’ for the company, Levy said.

The Boston brewer is expected to report second-quarter results on Thursday after the stock market closes.