A Look Inside Our Brewhouse

Brewing has often been described as a science and an art. At Harpoon, we work very hard to combine both the art and the science of brewing to create unique and flavorful beers to enjoy. Check out where the magic is made! 


The brewing process starts when different kinds of malted barley are mixed and crushed according to the specific beer's recipe. We need to use approx. 7000 pounds of crushed malted barley to make 120 barrels of beer (about 3800 gallons). Before brewing, North American malted barley is cracked open in the Grist Mill (photo).   By cracking open the husks of the grains of barley, the starches within are exposed. The malted barley is transferred to the grist case, where it is weighed according to the recipe.

Time Taken in this step: 30 minutes
Total Elapsed Time: 30 minutes


The cracked malted barley, known as grist, is then moved into the first part of our four-vessel brew house, the Mash Tun. Here, the crushed malted barley is mixed with hot water. The combination of water and malted barley is known as mash. This is where a natural chemical reaction takes place which breaks down the starches of the malted barley into simple sugars. This is achieved by a controlled raising of the temperature of the mash through a process called stepped infusion.

Time Taken in this step: 40 minutes
Total Elapsed Time: 70 minutes


We then transfer the mash into the second part of the brew house known as the Lauter Tun (photo) ("lauter" is a German verb meaning "to clarify"). The Lauter Tun has a screened false bottom that allows the grain husks to form a natural filter bed so that the sweet liquid (called 'Wort') is separated from the spent grains. The wort is then transferred into the Brew Kettle.

At the end of this stage, the spent grain (still rich in nutrients) is set aside and used by farmers as cattle feed.

Time Taken in this step: 150 minutes
Total Elapsed Time: 220 minutes


The Brew Kettle is the third vessel in our four-vessel brew house. The wort is quickly brought to a boil. Before, during and after the boil, different hops are added to the wort in the brew kettle, depending on the type of beer and desired bitterness and aroma.

Time Taken in this step: 70 minutes
Total Elapsed Time: 290 minutes


The hopped wort is then sent into the whirlpool, which is the fourth and final vessel of our brew house. Here the hopped wort is clarified and separated from the “trub” (protein, barley and hop particles). The hopped wort is transferred out of the whirlpool through a heat exchanger. This heat exchanger cools the wort very quickly, to about 70 degrees Fahrenheit, by running cold water through pipes parallel to those holding the beer, as it is sent to the uni-tank to ferment. 

(On an environmentally friendly note, we start the next brew with the water that is warmed up during the heat exchange, thereby reducing our energy consumption).

Time Taken in this step: 75 minutes
Total Time Elapsed: 365 minutes

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