Barrel entry proof continues to be a topic of debate amongst whiskey makers and avid whiskey fans, with some believing different proofs lead to different results.
Buffalo Trace Distillery was curious as well, and began an experiment on four different entry proofs with its rye recipe bourbon more than 12 years ago. Now these bourbons have come of age and are being released along with Buffalo Trace’s findings.
All of the experiments came off the still at a consistent 140 proof, but were put into the barrel for aging using four different entry proofs. All of the barrels were then aged together for 11 years, 9 months and bottled at 90 proof. Here are the details:
Rye 125 – At 125 proof, this was the highest entry proof used, which is also Buffalo Trace’s standard entry proof for its rye recipe bourbons. The result was typical of Buffalo Trace’s mash no. 1 findings, a well-balanced bourbon with spicy cloves mingled with sweet vanilla, caramel and toffee to create a well-rounded and complex flavor.
Rye 115 – This rye recipe bourbon was put into the barrel at 115 proof and has light oaky flavors mingled with leather and palm sugar.
Rye 105 – At an entry proof of 105, the angels were particularity generous with their share, taking the highest amount of their share in all four experiments with an evaporation rate of 26 percent. The 105 entry proof produced a bourbon which had a good overall flavor with some earthy tones, followed by a buttery, light finish.
Rye 90 – At an entry point of 90, this bourbon had a 25 percent evaporation rate as it aged alongside the other four experimental rye barrels in Warehouse K. The result was a bourbon with a light fruity flavor followed by some hints of dried nuts and spice, with a drier finish.
This rye entry proof experiment follows on the heels of Buffalo Trace’s wheat entry proof experiment. Both the wheat and the rye experimental groups of barrels were distilled around the same time, aged in the same warehouse, on the same floor, rick, and row and bottled around the same time.
A key learning for both experiments was that entry proof does affect bourbon flavor, and it does affect evaporation rates. Also, different barrel entry proofs will produce varying flavor elements.
“Although it should not be a surprise to us, we found in blind tastings the rye recipe with the 125 entry proof, which is our standard barrel entry proof for our rye recipe bourbons, tasted the best to us,” says Harlen Wheatley, master distiller. “The flavor profile was the most balanced, while still offering the most pleasant mixture of tastes. It’s gratifying to know that even in blind taste tests, we still favored our ‘standard’ method as the best of the four in the experiment.”
These rye recipe barrels are part of the more than 2,000 experimental barrels of whiskey aging in the warehouses of Buffalo Trace Distillery. Each of these barrels has unique characteristics that differentiate it from all others. Some examples of these experiments include unique mash bills, type of wood and barrel toasts. In order to further increase the scope, flexibility and range of the experimental program, an entire micro distillery, named The Colonel E.H. Taylor, Jr. “OFC” Micro Distillery, complete with cookers, fermenting tanks, and a state-of-the-art micro still has been constructed within Buffalo Trace Distillery.