Barreling proof ... what affect does it have on bourbon?

[higgins]

Most distilleries barrel at 125 proof, the max allowed by law. A few choose to barrel around 113 (Makers Mark, Weller), and fewer still around 103 (Michter's). How does it affect the end product? Is 125 the magic number because it produces the best whiskey (maximizes quality), or is it because the distillery needs the fewest number of barrels (maximizes profit)? I wonder if the proof affects what components are extracted from the wood? Last fall I spoke with a distiller at Michter's and he said they barrel at 103p because they feel it produces the best whiskey.

Time for an experiment to see for myself.

I made a bourbon in January of 2023, making enough to fill a 7 liter Badmo barrel and enough extra to do this experiment. The grain bill was 76% corn, 15% rye, 9% malted barley, fermented with a bourbon yeast from Wilderness Trail distillery (Ferm-Solutions FS917). It was double distilled using a pot still. I kept about 8.6 L (at 62.5%) out of 20 L collected (I went down to 25% off the spout)

I toasted 2 batches of white oak sticks that were ~5/8" x 3/4" x 5") in the oven (wrapped in foil). See picture for toasting times/temps. One of each stick was cut into 3 pieces about 1 3/4" long & were charred with a MAPP gas torch to about char 3.

I made up 6 jars (12 oz or 350 ml), 2 each at 103 proof, 113 proof, and 125 proof (I also kept another jar of 125p white). These jars had the standard lids & rings replaced with SS rings and PTFE discs (see note below picture).

1 each of the 3 proof jars got a medium toast stick, the other 3 got heavy toast sticks. Throughout the past year I have cycled these thru somewhere around 20 heat/cool cycles (90F/65F) in an insulated box. My protocol was: Open jars & swirl a bit; tighten lids & shake vigorously for 10 seconds; slightly loosen the lids & turn on the heat; wait a week & turn off the heat; wait a week & repeat.

NOTE: This pic was taken at 1 month. The lids originally had a sheet of waxed paper underneath. Shortly after this picture was taken I changed to SS lid rings with PTFE discs.

That was on Feb 3 of last year, so today is just 5 days short of 1 year. Me & 5 friends are going to evaluate them today. I've made copies of the Bourbon Tasting wheel for each of us and am asking everyone to write notes about each of the 6 oaked jars. I will compile the results and report back.

If they turn out to be good enough they might even make the trip to Murphy.

[Stonecutter]

Not sure if you’ve read this or not but it has some interesting information related to this topic.
http://whiskyscience.blogspot.com/2013/ ... ength.html

[higgins]

Thanks for that link Stonecutter - an interesting read.

[tjsc5f]

Good stuff as always higgins.
Have you already read up on the Buffalo Trace Experimental Collection and Maker's Mark DNA series where they did similar tests?

[higgins]

We had our tasting session yesterday afternoon.

I've compiled all the comments and removed duplicates, and there are a few conflicting comments. Once again, the grain bill was 76% corn, 15% rye, 9% malted barley, FS917 yeast.

White Dog in glass at 125 proof sampled at 90 proof:

• Aroma: young delicate malt, cereal, corn, geranium, grainy, rye, slight herbal spice, sweet corn
• Flavor: corn, floral, grassy, hints of spice, no burn, smooth, sweet corn

Med toast aged at 103 proof sampled at 90 proof:

• Aroma: alcohol sting, brown sugar, butterscotch, candy, caramel, graham cracker, hints of vanilla, honey, Maple, slight floral (rose petal), spicy (tobacco leaf), sweet, wood
• Flavor: balanced, black pepper, caramel, clove, Hint of burn, light body, light texture, rye spiciness, smooth finish, sweet, touch of grass

Med toast aged at 113 proof sampled at 90 proof:

• Aroma: butterscotch, caramel, corn, graham cracker, grain, hints of cinnamon, Hints of maple, medium nose, more subdued, oaky (raw & toasted), Slightly more aromatic, sweet corn, woody/nutty almond
• Flavor: astringent finish, balanced, cereal malt, grainy, hint of rye (begins low, increases), Initially no burn, but a little comes in later, less spicy than M103, rye pepper, smooth, spicy, toasted malt, toasted oak, touch of bitterness on side of tongue, tropical wood finish

Med toast aged at 125 proof sampled at 90 proof:

• Aroma: almond, buttery, candy sugar, caramel, cedar, cinnamon, clove, full nose, less bite than M103, pecan, sweet, toasted oak, vanilla
• Flavor: Complex grainy texture, full bodied, grassy, long finish, more complex, nice lingering aftertaste, nutty almond, rye spice, seems higher proof, sharp complexity, slight harshness, spicy - black pepper, super smooth, sweet, toasted, vanilla

Heavy toast aged at 103 proof sampled at 90 proof:

• Aroma: aromatic, backdrop of floral notes, caramel, cinnamon spice, definite oak, hint of alcohol, similar to M103, spicy, strong maple, sweet, toasty, vanilla
• Flavor: black pepper, burn may actually be rye, caramel, cinnamon, Long finish, pink heart flavors, rye spice on back end, slight harshness, slight hint of burn, spicy/sweet, sweet, very candy like, very peppery finish

Heavy toast aged at 113 proof sampled at 90 proof:

• Aroma: allspice, aromatic, caramel, cinnamon, oaky, peppery spice, rye, similar to M113, slight alcohol, spiciness, strong maple, sweet, toast, vanilla sweetness
• Flavor: A bit hot, cereal grain, good body and mouthfeel, less spicy, More complex than M113, NO burn, pepper like finish, rye spice at tail end, spicy, sweet, touch of grass, wood

Heavy toast aged at 125 proof sampled at 90 proof:

• Aroma: almond, caramel, cinnamon, dark fruit, higher alcohol, Lower aroma level, maple turning to vanilla, more complex, not much oak, nutty almond, oaky, similar to M125, spicy, sweet floral (dandelion), vanilla
• Flavor: candy, caramel, chocolate, grainy malt, hints of alcohol, honey, maple, No wood in flavor, peppery dry finish, silky mouthfeel, slight spicy rye, smooth very tasty, sweet, toasted oak, vanilla, very smooth, walnut

General Comments

• Really surprised how smooth H125 was compared to other aging proofs, Heavy toast all had more intense toasty character than Med toast, More vanilla, nuttiness, Heavy toasted jars seemed older than medium toast jars

---

There was no consensus on best/worst/etc, just consensus that all were different, all were good, and in general, the lower aging proof samples were a bit sweeter, and the higher aging proof samples were a bit drier.

I was surprised at how mature (and GOOD) these 1 yr old jars seemed to be. IMO none were over-oaked, and although there were a few comments about astringency, I never picked that up. Some will definitely come to Murphy with me.

These results do seem to support the concept that the lower proof aging does bring out the more water soluble components of the oak (such as wood sugars), and the higher proof aging brings out the more alcohol soluble components (such as vanilla). I may start making 4 qt Badmos and split batches at different proofs. In addition to these 12 oz jars, I have a full Badmo of this bourbon that is the same age. I think I need to sample that!

[kennstminet]

Higgins
I've sorted you to the "non bullshit speakers" drawer.
Thanks for your great writeup.

[OtisT]

Hi Higgins. Thanks for putting in the work on these tests and sharing your findings. Great write up. I know I’ll be coming back here in the future for reference.

[higgins]

I took samples from this experiment to the Southeast Meetup a few weeks ago, where they were sampled by Dougmatt, Steve Broady, and myself.
As I did earlier for my local group, I proofed all samples down to 90 for the sampling.

Consensus seemed to be that at this point in time those aged at 113 were preferred over the others, and in general the heavy toast preferred over the medium toast. Those at 125 were generally drier and a bit more complex, those at 103 were sweeter and less complex. H113 was liked the most, M125 the least. BUT - a blend of all six (4 ml ea of the 2 aged at 113, 2 ml ea of the others) was great! It had both complexity and moderate sweetness, which melded very well.

It was apparent that aging proof affected what characters came from the wood, and that the characters extracted at each proof were desirable, some more so than others. We talked about varying the proof during aging, starting at 125, proofing down to 113, then to 103. Maybe a year at each proof.

I'm going to do that with my 2 latest bourbons going into badmos (identical grain bills, 1 standard cook/mash process, 1 YLAY).

[Twisted Brick]

Fantastic write up, Higgins. Thanks for sharing.

[NormandieStill]

It was apparent that aging proof affected what characters came from the wood, and that the characters extracted at each proof were desirable, some more so than others. We talked about varying the proof during aging, starting at 125, proofing down to 113, then to 103. Maybe a year at each proof.

I'm going to do that with my 2 latest bourbons going into badmos (identical grain bills, 1 standard cook/mash process, 1 YLAY).

Did you ever see this thread on the straightbourbon.com site about slow proofing in the barrel? If not, you should absolutely read it, and then do your experiment. I want to try the same at some point... when I've finished all the other experiments.

[BoilerMaker]

Thanks for the effort and write-up.

...
It was apparent that aging proof affected what characters came from the wood, and that the characters extracted at each proof were desirable, some more so than others. We talked about varying the proof during aging, starting at 125, proofing down to 113, then to 103. Maybe a year at each proof.
...

I've thought about that too: it's one of the many things hobbyists can do to differently than commercial producers to create unique spirits. Might be the first time it's been suggested here - cool that you and the SE crew got the wheels turning.

[Edit: From the article NormandieStill linked in, it looks like craft distilleries are already on it!]

[zach]

Consensus seemed to be that at this point in time those aged at 113 were preferred over the others, and in general the heavy toast preferred over the medium toast.

Nice Work!

I wonder the if lower dilution factor 113 -->90 versus 125 ---> 90 provides more flavor & sugar from the wood thus the preference.

I've tasted a number of cask strength scotch whiskies neat in the 100 to 115 proof range that were great and then with just a few drops of water from an eye dropper opened up the flavor to something more complex. Finding the optimal bottle strength is another part of the puzzle. I enjoy many whiskies above 100 proof.

[Dougmatt]

Just a comment to say I really enjoyed the opportunity to sample these during the meetup! Really changed the way I’ve been thinking about aging. Thank you!

Higgins sent through an article after the meetup suggesting that maybe reverse step up is even better. Ex: First fill 103, second fill 113, third fill 125. This supposedly allows the first sprit to deplete the wood of lower proof accessible sugars and each progressively highly proof able to access something left behind, suggesting that if you put in 125 first (for example) it will pull out everything that proof and below. I would expect you would start them in reverse then move them ahead for finishing proofing down along the way.

I can’t seem to find the link, but will post it if I can dig it up.

PS…. I found this meetup to be a great knowledge and experience sharing event and hope to attend more.

[Steve Broady]

Sounds like an interesting experiment. Use the same wood twice, once at a lower proof and then again at a higher one. Then perhaps blend the two spirits together.

[Ridgeback816]

So from every thing I have read and tried says to use wood at 125 then 113 then 105 because it's the water that pulls the tannins out of the oak not the ethanol.
I have had great results with rye whiskey at 125 for 18 months bourbon second us at 113 for 24 months then staves added to rum for 6 months (to be fair the rum was aged with cherry for a year first) although I am going to try a larger barrel (for me 5 or 10 gallons) first use for bourbon so I can push it 3 to 4 years.

[Bolverk]

What a cool experiment!


Historically speaking, 100-105pf was what everyone was doing pre-prohibition. It wasn't until the mid-1960s when the ATF (now TTB) allowed for the higher entry proof. From research and interviews I've heard, that decision to go to the high proof was 100% driven by the bean counters. Manufacturers would need fewer barrels, rick houses, etc... every account I've heard from old-time distillers from before the bump in barrel proof said they would have stuck with the 100pf entry point if they could have.

[tommysb]

From a practicality point of view - starting with a higher barrel entry proof, and every 6-12 months refilling the losses from the angels' share makes most sense to me. The exact numbers probably don't matter that much. That way you get the advantage of different proofs pulling out different flavour compounds and a more complex spirit (assuming that this is the case, which makes sense), without the hassle of removing liquid, rebarreling, calculating, etc etc. Since Higgins's (excellent) experiments tend to suggest that there's not one 'best' barrel proof, just differences at different proofs, hitting precise proofs at precise intervals isn't that important.

The thread Normandie shared is really interesting - it seems that this technique is already used by french distillate producers who also seem to do something similar on the timescale of many years.

[Pookie]

I tend to age around 128 to 110 with good results, I have a 2022 hbb that is phenomenal, notes of leather and caramel. I think It depends alot on wood quality and conditions of aging

[higgins]

From a practicality point of view - starting with a higher barrel entry proof, and every 6-12 months refilling the losses from the angels' share makes most sense to me.
...

+1

That's what I had planned on doing to get all the goodies from the barrel at multiple proofs. My stuff goes into Badmos at 125p, but since I don't get much evaporation with Badmos, I'll just have to drink some to make space for the top up water.