Our rye whiskey has a unique grain bill made up of 60% rye, 30% wheat and 10% malted barley. 90% of our grains are sourced locally from Lancaster and Lebanon counties here in Pennsylvania. Prior to mashing in our grains are milled to a flour like consistency. Milling our grains to such a fine grind allows us better conversion of the grain starch into sugars; and unlike beer makers or many other distilleries we will not separate the grains from the liquid before fermentation. Once the grains are introduced into the mash they will stay in for the entire process. We believe that distilling "on the grain" produces a more flavorful product.
During the mashing process we heat water in our mash-tun. Once the water reaches the strike temperature the milled grains are introduced and stirred in. The temperature is slowly increased to bring the mash up to the conversion temp. At this temperature a process called saccharification starts breaking the complex carbohydrate (starch in our case) into simple sugars. After the majority of the starch has been converted we begin cooling the mash down. Fresh water used to cool the mash will be saved and used on the next run. This helps reduce water usage and also means the water is pre-heated; thus reducing the energy needed to heat the next run. Once the mash has been cooled to 95F the yeast is added and then its pumped over to one of our fermenters.
During fermentation the yeast will consume the sugars created during the mashing process and transform them into alcohol. At Thistle Finch we ferment hot and fast. Our temperature controlled fermenters are set to keep the mash just cool enough to keep the yeast alive, and a typical ferment will last between three and four days.
Once the fermentation is complete we pump the mash into our hand built 150 gallon pot still and bring it to a boil. Our still was modeled after German built hybrid pot stills and has four valve plates and a dephlegmator, or reflux condenser. Most distilleries with a similar setup run their equipment in a way that attempts to maximize the amount of reflux in order to concentrate the whiskey collected. We intentionally de-tune our runs in order to bring the distillate off at a lower average proof. This means we do not need to add any water to the collected whiskey prior to barreling, and have to add a lot less water when proofing down to bottle strength. This unique method of distillation is what gives our un-aged whiskey its surprisingly smooth taste and full flavored character.