By Green Energy Times Staff
Almost two years have passed since we had an article on the Woodstock Inn, Station and Brewery in North Woodstock, New Hampshire. We wanted to revisit the inn with special focus on the brewery.
The inn has two solar systems, one photovoltaic (PV) and one thermal. The PV system provides for the electric needs of the inn and brewery, as 90% of the heat comes from five air-to-air heat pumps. The solar thermal system provides hot water. Altogether, solar power provides for about 70% of the energy.
The buildings are energy-efficient. The building envelopes were built, sealed, and insulated to high modern standards. As usual, this implied a need for heat-recovery ventilation. There are, however, complications for energy use, and in this sense a brewery is rather like an industrial plant.
Brewing beer starts with malt, grain that has been allowed to begin sprouting, and then has been dried. As the grain starts to sprout, it produces enzymes that will convert the starch in the grain to sugars, which yeast can ferment. The malt has to be “mashed,” which means that it is steeped in hot water, for the starch conversion to happen. The resulting liquid, with sugar in it, is called “wort.” It is boiled for an hour or more to produce the right flavor. Then it is quickly cooled to the correct temperature for fermentation.
All of these processes use energy. Boiling a thousand gallons of wort for an hour is not a trivial matter. The power for this part of the operation is provided by propane. Cooling things off requires energy also. Clearly efficiencies are called for.
One efficiency results from the facts that water for mashing has to be heated and that the wort has to be cooled quickly after it is boiled. The wort and the incoming water are put through a heat exchanger, so the heat from the wort pre-heats the water for mashing. Because the wort has to be cooled quickly, a plate heat exchanger is used with metal plates whose large surface allow for rapid transfer of heat.
The wort is then further cooled to the correct temperature. The water that got much of its heat is stored in an insulated tank until it is needed.
Of course, there are other matters of ecological interest besides cooling and heating liquids. Breweries create spent grain by the ton. The grain still has enough nutrition in it to be useful. For that reason it is often used for feeding farm animals. The Woodstock Inn’s grain is used at Meadowstone Farm, in Bethlehem, New Hampshire, where it is used to feed chickens. Any excess grain beyond what the chickens will eat is composted.
Woodstock Inn, Station and Brewery’s beer is distributed throughout New England.