WORCESTER — When Wormtown Brewery opened in 2010, people were still calling craft breweries “microbreweries.” Taprooms — the cornerstones of most breweries today — were illegal in Massachusetts.

There were fewer than 50 breweries in the state, none within 20 miles of Worcester. By the end of this year, Massachusetts will have 250 breweries. The city’s sixth opened last month.

Over the last decade, Wormtown has changed, too.

The brewery that started in a tiny backroom at Peppercorn’s now takes up 24,000 square feet on Shrewsbury Street, with a new taproom and seven-barrel brewhouse at Patriot Place in Foxboro. It brewed 700 barrels in 2010 — about what it brews in a week now — and expects to produce more than 36,000 this year. It had four employees in 2010; it has more than 50 today.

The brewery had an anniversary party scheduled at both taprooms for this Saturday, but the celebration has been delayed to May 9. 

And it wouldn’t be a Wormtown bash without new beer, including “Decade Dance,” a robust imperial pastry stout brewed with 55 gallons of maple syrup. And Wormtown collaborated with Table Talk Pies again; this time, instead of a pumpkin pie ale, the brewery used blueberry and lemon pies for a light kettle sour.

Last week, I met with co-founder and brewmaster Ben Roesch and managing partner David Fields in a newly constructed employee loft at the 72 Shrewsbury St. brewery. We talked for nearly two hours about the previous 10 years at Wormtown and how their industry has changed in that time. Below is a snippet of our conversation, edited for clarity and space.

What was one of the biggest factors in Wormtown’s growth?

Roesch: In 2012 we started canning “Be Hoppy” with IronHeart Canning and that really propelled the brewery and that beer to the next level. So that was the workhorse that came about at the end of 2012 with canning and Be Hoppy becoming the big beer for us, especially in Boston. That market kind of established Be Hoppy as the beer from Wormtown Brewery that people wanted to see.

Did that put a lot of pressure on you?

Roesch: There are periods of time over the last 10 years where certain things have happened and certain styles have become popular. For instance, Brut IPA. For a while, everyone was brewing a Brut IPA or a Champagne-style IPA. We would have done one. It would have been fun. We just didn't have the ability to do it, because of our batch size requirements, and the fact that we were cranking out barrels. From when we opened in 2010 until probably a year or two ago, we didn’t have the capacity. We were brewing to try to give all of our sales and distribution forces enough beer to go out there and do what they needed to do. When we were able to get the whole second half of this building, we could put in enough capacity with fermenters and bright tanks and operate the brewhouse on multiple shifts. So we’re now able to go out and plan stuff. Before the plans were all about making more beer. Now the plans are about creating brands and building out a portfolio that isn't just Be Hoppy.

How does Patriot Place figure into those plans?

Roesch: It allows us to go back to the situation we had back in 2010, which was a smaller brewhouse, and gives us the ability to make some more unique things. We're able to get a little funkier.

Have you brewed there yet?

Roesch: Three batches so far. We probably will have five or six in the tanks by the time we get to the birthday party. The first batch was the first batch we brewed in Worcester, as well: Seven Hills pale ale. That will be on tap at the parties. There is no better way to calibrate a brew system than the beer we first brewed.

Has the taproom been busy even with no football?

Fields: The No. 1 question I'm asked is, "It's the beginning of March now, are you guys still open this time of year with no Patriots games?" Every single Friday and every single Saturday and Sunday in January through March have been significantly busier than here in Worcester. It is a destination location.

What do you find most fascinating about how the industry has evolved in the last decade?

Fields: We came in and there were no taprooms, then it became legal, but the idea of it as your volume driver, even when it became legal, didn't exist. Fast forward today, and everybody is opening up saying, "Well maybe I'll have a few places sell my beer, but I want everything else to be sold on premise." The shift to taprooms changed, and the shift to focus on taprooms was a complete change.

I remember we were looking at one of our final drawings when we were months into construction here, and they handed us a design, and the taproom was two-and-a-half times the size it is now. We both looked at each other and said, "What is that? We don't need that much space for our taproom. We need production space." And we had them shrink our taproom by at least 50 percent, maybe more. If we knew what we knew today, we would have made it two-and-a-half or three times the size it is now.

What are you most proud of when you look back at the last 10 years?

Roesch: For me it's our employees: The fact we could grow this business to have employees who are with us, who have all the things I wanted when we opened this brewery — a consistent paycheck, health insurance, 401k.

The reason I opened up a brewery was because I wasn't feeling secure as a brewer out there in the world, when there were only 35 to 40 breweries and a lot of them were pretty marginal. I wanted to open up something so I could feel secure in my occupation, and my greatest achievement here was we have all these other people who are able to share in this. Now it's just up to David and I and the other partners to be stewards of that and make sure we grow in a sustainable way and continue adding quality to their lives.

This story has been amended to reflect the postponed anniversary celebration.