With one small pour of grain into the mill Monday morning, Worcester’s five breweries took a giant leap in producing a collaborative beer.

Crushed gain shot through the mash tunnel into a porridge-like substance in a large stainless-steel barrel at Redemption Rock Brewing Co. Though, a representative from each brewery took turns in stirring the hot water to ensure the grain mixed well with the water.

“I’ve had my workout for the day,” said, Meredith Winnett, a brewer at Greater Good Imperial Brewing.

“A workout for the entire week,” another brewer joked.

The brew, a coffee brown ale, will debut at Mass Brewers Guild’s “Great Mass Collab” beer festival on Sept. 21 in Worcester.

Redemption Rock Brewing Co., Greater Good Imperial Brewing Co., Wormtown Brewery, 3cross Fermentation Cooperative and Flying Dreams Brewing Co. all contributed to the project.

They named the ale “Snoopy Cap,” which was also the device American astronauts used to transmit words from the first space capsule to touch down on the moon.

The device was made by David Clark Co. in Worcester.

The connections to Worcester and Massachusetts go beyond the name.

The brew used grains from Valley Malt in Hadley. The hops came from Four Star Farms in Northfield. Worcester’s Acoustic Java provided the coffee.

“We knew we wanted to use those things, so a brown ale kind of jumped out at us,” Redemption Rock Brewing Co. co-founder and brewer Greg Carlson said.

Monday’s batch will produce 16-20 kegs once it’s complete. The small size was one of the reasons Redemption Rock offered the best site to brew the collaborative beer.

“A lot of the other guys, they’re on 30 or 20 barrel systems. They’re pretty big,” Carlson said. “We knew we didn’t need to do a batch of that size so we wanted to do a 10-barrel brewery.”

It came down to Redemption Rock and Flying Dreams.

Redemption Rock had the tank space.

“I had a feeling from the get go it was going to get done here,” Carlson said.

Carlson checked the temperature of the concoction that he described Monday as a porridge. He smiled when the got the results he wanted. Representatives from the four other breweries all joined Carlson with a quiet cheer.

“Co-collabs are very popular in the industry right now, but I haven’t seen something like this, it’s the first one I’ve seen in Massachusetts,” he said.