GRAND RAPIDS, MI — If you thought Founders Brewing Co. had gotten big in the last couple years, wait until you see it next spring.

By May 2015, the Grand Rapids brewery plans to complete a $25 million expansion project that will double its beer-making capacity to 600,000 barrels.

The brewery is just a couple weeks away from deciding whether to build the new manufacturing space at its downtown facility or in another location around the Grand Rapids area, said CEO Mike Stevens.

"We are trying to move fast and furious," said Stevens, who just last year shepherded Founders through a $26 million expansion of the brewhouse, cellar and company taproom at 235 Grandville Ave. SW.

“Just in the last couple months, things have heated-up for us quite a bit,” he said.

“Sales just have not slowed-up one bit. We’re seeing one of the strongest years we’ve seen in our history.”

Overall sales are up 54 percent over 2013, said Stevens. Sales of All Day IPA, a session ale that Founders spent four years perfecting as a flagship brand before debuting last summer, is up 138 percent over last year.

All Day IPA is not the only Founders beer surging in sales. Centennial IPA is up 63 percent over 2013; Dirty Bastard is up 48 percent, and Founders Porter is up 87 percent, he said.

On Tuesday, July 1, the brewery also announced a new addition to the specialty lineup: Dark Penance, an imperial black IPA that lands in October.

Related: All Day IPA: The beer that almost wasn't

“We’re really seeing broad growth from the entire portfolio,” he said. “The Founders brand and name is really gaining momentum and credibility.”

Founders, which moved from No. 30 in 2012 to No. 26 on the list of largest craft brewers in the country last year, has enjoyed a 67 percent compound annual growth rate since 2008, which Stevens called “a record growth rate, definitely, in our industry.”

More of the company beer is showing up in more places every day. Bar and restaurant distribution is up 61 percent over last year, and store sales are up 45 percent, Stevens said.

The growth is starting to put pressure on the brewery’s ability to fill orders, said Stevens. The expansion is an attempt to build some cushion into that process and increase the brewery’s ability to meet demand during peak times.

The company plans to finance the new construction with a combination of cash reserves and taking on some debt, Stevens said.

The expansion would likely boost the number of employees from 250 to 300, he said, mostly in the brewhouse, cellar and packaging departments.

Stevens expects Founders to make about 195,000 barrels of beer by year’s end, but said the company has been brewing this year at about 250,000 barrels-per-year rate.

While past expansions were somewhat headache-inducing, Stevens said the company’s executive leadership team and financial security have evolved to a point where doubling in size in less than a year is a doable endeavor.

“Hopefully, we’ll be able to stay well ahead of the curve in terms of supply and demand."

Garret Ellison covers business, government and breaking news for MLive/The Grand Rapids Press. Email him at gellison@mlive.com or follow on Twitter & Instagram