Birectifier Analysis of Rabbit Hole’s Boxergrail Rye

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It has been a long time since I picked a role model spirit to analyze and a long time since I’ve looked at rye. The last look at rye was when Old Overholt bonded was released in 2018. The latest spirit that has really grabbed my attention is the Boxergrail rye from Rabbit Hole. During the pandemic I have somehow returned to being a bar manager and tasked with keeping the ship on the rails. Boxergrail turns out to be my very first new placement as dining has slowly returned. It may even see some use on the cocktail menu blended with a very particular Bourbon. We may be the first place in Philadelphia to carry it and I love making markets for spirits I really enjoy.

We did the staff tasting standing up, right before a busy service started, lifting our masks to take small sips. There was strong consensus that the spirit has a unique and wonderful persistence. I bought a bottle for myself and have slowly enjoyed it while keeping up with the rum correspondence. Not many whiskies can hold your attention when you are addicted to rum.

I don’t believe in conventionally reviewing spirits but I do believe in both describing and investigating them. This unique look is also pretty much only aimed at distillers and spirits writers. Reviews don’t tend to account for quality for purpose or the economic reality of the producer. Agricultural products are fragile and it can be wrong to critique them in a way that may damage their sales. That being said, Boxergrail is ambitious and delivers! It’s purpose is profound and is still a value at its price, but it is a shame I cannot pour it all over my cocktail menu!

With its 95% rye, 5% malted barley mash bill, Boxergrail is special and I wanted to know why and where (by volatility) so of course I examined it through the lens of the birectifier. For comparison, the mash bill of Overholt is undisclosed but very likely an economy 51% rye with the minimum of malt. Boxergrail is aged over 3 years in new charred oak while while Overholt is 4+ years old and also aged in new charred oak.


Fraction 1 was unique and followed a similar story line established by Overholt, but with less concentration. There was possibly less ethyl acetate due to age which may really benefit elegance and there were also extra details not seen in fraction 1’s from other spirit types, namely a subtle banana character. If there is extremely volatile aroma inherent to rye, too much generic heady aroma may over shadow it. If that is true does Boxergrail strike a perfect balance? If it spent more time in the barrel could it ever lose elegance? Spirits should be mature, not old.

There was a note like banana that appeared more clearly in the subsequent fractions of Overholt which is interesting.

In fraction 4, we see another contrast between Overholt bonded that may be another key to Boxergrail’s elegance. It may have less fusel oil as compared to the frightening wraith of Overholt. The fusel oil wraith is not necessary bad because I love Overholt bonded as is but that is my metaphor for experiencing this fraction organolpetically in a concentrated form separated from other congeners. It penetrates you with a characteristic sharpness, almost like breathing in a demon. Roughly 75% of the fusel oil lies in fraction 4.

If we can say Boxergrail is possibly below average in fusel oil, how did it get that way? Was it by distillation such as distilling at a higher ABV or was it by careful attention to fermentation that minimized fusel oil at inception? Much of spirits production is garbage-in/garbage-out. It is challenging but always best to minimize fusel oil during fermentation. Less fusel oil helps justify lower distillation ABV and thus the capture of more high value aroma that is less volatile.

The fifth fraction was incredible in both spirits, but upon reflection my notes seems a little more dazzling for the Boxergrail. It does hold the advantage of far more rye to draw aroma from. The rye is also supposedly carefully selected from beyond the typical commodity stuff. Hallmarks of quality were all over this fraction. No doubt this is where much of the persistence that makes Boxergrail so luxurious comes from.

The last three fractions showed no signs of anything that could be called a flaw and instead just had a warm pleasant character. There was no distinct gustatory acidity such as what is found in very heavy rums and I didn’t really expect any. I don’t have enough strong remembrances of Overholt and I noted some characteristics that I did not find in Boxergrail. It would be great to perform more American whiskey case studies, especially for progressively aged distillates to track maturation.

The birectifier as usual is an incredibly insightful tool to examine distillates. The results can be far easier to interpret than GCMS and at a fraction of the cost. We now have strong insights on why Boxergrail is so special and how to compare it to other American ryes.


Fraction 1: Concentrated to a reasonable point. No overly gluey non-culinary aromas. This may be due to the youthful age. Almost sensing an additional fruit note like banana that I haven’t noticed in other fractions 1’s. Something wholesome.

Fraction 2: Diminutive version of fraction 1 as expected.

Fraction 3: Extremely neutral as expected.

Fraction 4: Definite whiskey fusel oil. Not exactly the penetrating wraith I have encountered in other whiskies.

Fraction 5: Incredible concentration. All the rye character concentrated to the point of being a perfume but subtracting the weightier character seen in fraction 6,7,8. You see what can power so much persistence and unique percepts. The concentration makes it bewildering and the descriptors don’t exactly fly but you see where they come from. This fraction is slightly cloudy. On the palate it is slightly acrid due to concentration. I do not see any obvious droplets. I do not sense any rum oil/damascenone.

A second taster got coffee and called out that specific object comparison quickly.

Fraction 6: This bridges rye character and the warm pleasant character of fraction 7 and 8.

Fraction 7: Very similar to fraction 8. No significant gustatory acidity.

Fraction 8: Warm aromas. Light but more significant than I expected and quite pleasant. I wonder if the new oak plays a role? No significant gustatory acidity.

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