At this point I think I’m the only person not employed by Buffalo Trace to continue the “Single Oak Project” experiment, but I remain excited by it and am committed to seeing it through. This month we look at the sixth round of Bourbons, now a year and a half into the four-year experiment to figure out what really makes the best Bourbon.

Previous rounds can be found here:

Round One (including all the basics of the approach to this series)
Round Two
Round Three
Round Four
Round Five

Here’s every barrel reviewed on one page

This round considers the effect of recipe (rye vs. wheat, which so far has been tested in every round), barrel char level (#3 vs. #4), and wood grain size of the barrel (tight, average, or coarse). All other variables — tree cut, stave seasoning, aging warehouse, and entry proof — remained the same.

All of these are 105 proof entry-proof whiskeys, which is a curious choice, and results were all over the map. Both of my favorite whiskeys — #30 and #160 — were both ryes, one with a #3 char and one with a #4 char. None of the wheated whiskeys performed particularly well this time out.

To date, the leader among online reviews remains barrel #106. Thoughts on all whiskeys tasted follow. 120 Bourbons to go!

Buffalo Trace Distillery Single Oak Project Barrel #30 – Good all-around Bourbon, classic structure, vanilla, marshmallows, toffee. Long finish, very smooth. A- (rye, 105 entry proof, level 12 seasoning, tight grain, concrete ricks, #3 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #32 – Spicier, but not overdone, more wood oils here, a bit rough on the finish, and a touch bitter. B (rye, 105 entry proof, level 12 seasoning, tight grain, concrete ricks, #4 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #62 – Whole lot of menthol on the nose, some fuel oil. A bit rubbery on the finish. C- (wheat, 105 entry proof, level 12 seasoning, tight grain, concrete ricks, #3 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #64 – Hospital notes on the nose again, band-aids and astringent finish. Not quite as severe as 62, but still off. Like it hasn’t properly aged. C (wheat, 105 entry proof, level 12 seasoning, tight grain, concrete ricks, #4 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #94 – Hot on the palate, with a big spicy kick, but it mellows out and finishes with a smooth, dessert-like caramel silkiness. Coming together, but imperfect. B+ (rye, 105 entry proof, level 12 seasoning, average grain, concrete ricks, #3 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #96 – Very woody up front, and astringent on the back of the palate. Develops licorice notes, black cherry, and a nicely sweet finish. Like #94, it’s got two faces, and the second face is the better one. B+ (rye, 105 entry proof, level 12 seasoning, average grain, concrete ricks, #4 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #126 – Chewy but with a very light body. Overall a classical structure that reveals caramel and brown sugar in the end, but not a lot of depth. B (wheat, 105 entry proof, level 12 seasoning, average grain, concrete ricks, #3 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #128 – Lots of heat on this one, fading in the end and leaving behind a short finish. Not a lot of flavor at any point along the way, though. Harmless. C (wheat, 105 entry proof, level 12 seasoning, average grain, concrete ricks, #4 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #158 – Big toffee sweetness on the front of the palate, almost cotton candy like, a real departure vs. some of these more reserved and withdrawn spirits. A sugar bomb, almost a bit much. B+ (rye, 105 entry proof, level 12 seasoning, coarse grain, concrete ricks, #3 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #160 – Finally a real thoroughbred. This one has it all, up-front sweetness, depth of flavor, a touch of spice, and lush and lacy caramel notes throughout. Touches of citrus raise the game. Best of the lot. A (rye, 105 entry proof, level 12 seasoning, coarse grain, concrete ricks, #4 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #190 – Also very good, but with a bit of heavy alcoholic vapor to it. Racy, with dark molasses, dark chocolate to it. Missing something, but not a bad whiskey on the whole. B (wheat, 105 entry proof, level 12 seasoning, coarse grain, concrete ricks, #3 char, bottom half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #192 – Similar notes to #190, with more of a spicy, chewy character to it. Some greenness on the finish, too, and the dark cocoa notes don’t entirely mesh. B (wheat, 105 entry proof, level 12 seasoning, coarse grain, concrete ricks, #4 char, bottom half of tree)

$46 each (375ml bottle) / singleoakproject.com