Barrel ageing making the Rum "hotter"

[Al The Chemist]

I've made a heavy Rum and placed it in a virgin 4 Gal (white oak, medium toast) barrel for aging. This is not one of those hobbyists ornamental barrels, it was professionally made and charred to order. Its been just over 2 years now. The Rum was very pleasant pre-aging, and  I was expecting that beyond the tannin and caramel/vanilla notes, the oak aging will mellow pit the Rum further as well. 

Though the longer its been aging the "hotter" its becoming. Its becoming hard to drink. I was hoping it would reach a peak and then stat to mellow, but I'm seeing no sign of that. 

Any idea as to what might be going on?

 

 

[adamOVD]

Depending on your climate, two years is a very long time to age in a barrel that small. I think most people aging in 5 gallon barrels only go for about 6 months. You have probably over extracted the wood tannins, and that is the "heat" you are tasting.

[Al The Chemist]

The ambient temperature of the room I store the barrel is a bit warm. Around a pretty stable 70, which I understand is not ideal. 

That sux to hear. I was hoping that more time will result in a better aging, smoother pallet. How are the longer aged Rums done, X.O.s and the likes? A more depleted barrel, less charring?  

Is there anything I can do to save it? Or am I looking at a 2 Y.O. neutral spirit in the making. 

[Roger]

I don't believe there is a major rum on the planet that is aged in new charred oak. You should have probably put whiskey in your barrel for a year, dumped it, then added the rum. That would have gotten you closer to what you are looking for. You could also dump what you have now, and refill with white rum, and the next batch should be more palatable. 

Prost 

[DrDistillation]

Out of curiosity what was the char level of the barrel and what proof did the rum enter the barrel and come back out as proof wise?

[Al The Chemist]

Barrel was a 4 out of 10 (1 being neutral 10 being charred to a crisp). Rum went in at ~55% and is now 57%. 

Odd, I was expecting the alcohol level to go down. 

[DrDistillation]

Char numbers are usually 1 through 5.

You picked middle of the pack on the ABV for going into the barrel which was just fine.  Lower proof closer to 100 proof will pull more of the vanilla flavors while higher proof like 125 will pull more tannin and astringent flavors.

Different parts of the world will see different proofs out of the barrel.  Depends if you are in a dry vs humid climate, hot vs cold, etc.  Does more water evaporate vs more alcohol evaporate at a faster rate.  As others have said 2 years is a long time in a NEW 4 gallon barrel.

Your issue could be length of time in the barrel, lack of good char, fact it was a new barrel or just the barrel itself.  Keep in mind 10 barrels made right after each other may develop different tasting spirits even when stored right next to each other.  Some barrels may taste super, others not to good and other as expected.  That's why people blend barrels to get consistency.  With only a single barrel you are at the mercy of the Gods and wood.

The good news, is you now have a good used barrel for your next batch.  You now have to decide what to do with your present 4 gallons of spirit.  You say it's getting hard to drink so that would seem to indicate either to re distill it or use it to blend back with other rum you make.  Only you can figure out which way to go with this.  You may be able to use 10% to 20% mixed with other aged rum as a blend.  You might be able to LIGHTLY process it through some cleaned activated carbon to remove some of the taste.  If you try this use a small sample and go easy on the carbon.  Better to run the sample 3 or 4 times to see how much is needed vs using a lot on the whole batch. You might end up with a nice light rum this way.

Have you given thought to trying any of these things?

One thing to keep in mind if the taste is going down hill you will want to get it out of the barrel as it will likely just keep getting worse.  Ideally you will have something to put right back in the barrel.

[kleclerc77]

I'm surprised there was any rum left! The loss in those small barrels is usually huge. 

[Al The Chemist]

@kleclerc77 I am as well, there was surprisingly little loss. 

 

@DrDistillation, I've only considered the blending option. I'll give the others a go. Very helpful, thanks!

On the bright side, there is so much caramel/vanilla in this batch, it will likely make a great blender. Do you by any chance know what compound creates the "heat"? 

[bluestar]

2 years in a 4 gallon! And little angel's share loss? That must be some dense oak. Don't know what YOU mean by hotter. Normally, I think of heat as resulting from ketones in virgin spirit, that aging almost always reduces. Now harsher is different than hotter. I would expect it to be harsh. Oddly, if you are not getting much angel's share loss, you could just leave it in the barrel, it might mellow out in a year or two. Also, how does it taste if you dilute it with large quantities of unaged rum? Say, 2-5 parts white to your 2yo? If one of those tastes good, you could make "light rum", which is a blend of aged and unaged rum.

[Al The Chemist]

My reference to hotter is the feel of alcohol burn in the mouth and throat. Adds to the opposite of smooth :) oddly this is exactly the profile I was expecting the barrel to mellow out. 

The oak has to be quite dense. Flavor on the rum is great. Like an good aged whisky with rum overtones. Nice and heavy, full of flavor. Wish it was more palatable. 

Blending is definitely an option.  

[DrDistillation]

Are you tasting the spirit at 80 (or bottling) proof after letting it rest at least 20 minutes covered after adding the water to bring the proof down?

Alcohol, especially in high concentrations, will irritate the oral mucosa. That irritation can come across as a burning sensation, the same kind of thing that happens with capsaicin (found in varying concentrations in hot peppers). Alcohol’s also a solvent, absorbing some of the moisture from that mucosa and causing a drying sensation that can also present itself as a burning feeling.

To me the above really stands out making a vodka a couple of different ways.  For example vodka made using a sugar wash almost always seems "hotter" to me than a grain wash of corn & oats.  Why?  Well oats is known for it's "mouth feel" or "body" it adds to the spirit.  The sugar wash is like eating a pepper while drinking water while the grain based vodka is like eating a pepper and drinking milk.  The milk adds some "body" and "cooling" to the mucosa so the pepper doesn't appear as hot.

So what am I getting at?  You can likely tame this "hotness" down with some glycerin.  You can pick up a small 4 to 6 oz bottle at nearly any grocery, pharmacy or Walmart for $5 to 8 bucks.  Pour a shot glass of 80 proof rum and add a drop of glycerin and taste it.  Try two or three drops in the shot glass.  Does it help remove some of the heat? How about the body of the spirit now?  Did it improve the spirit?  A lot of people use glycerin as a fix for vodka or to give it body.

It's worth a shot and usually a good thing to have on hand these days anyway as it's one of the ingredients in the WHO hand sanitizer formula.

If you don't have glycerin available, you could try a 2:1 simple syrup you can make quite easily as well. 2 parts table sugar, 1 part water heated on the stove to a thick liquid then let cool.  Same thing many bartenders use for cocktails rather than adding sugar since it's already liquid and mixes much easier. You could use panela or brown sugar as well.

Other things you could try just for the sake of it would be to try tempering the spirit to 80 proof using coconut water vs distilled/ro water.  You might gain just enough "body" this way to help kill the heat a bit as well and some people like a coconut flavored rum (think Malibu).

Just experiment with very small amounts.

[bluestar]

On 4/24/2020 at 2:24 PM, Al_The_Chemist said:

My reference to hotter is the feel of alcohol burn in the mouth and throat. Adds to the opposite of smooth oddly this is exactly the profile I was expecting the barrel to mellow out. 

The oak has to be quite dense. Flavor on the rum is great. Like an good aged whisky with rum overtones. Nice and heavy, full of flavor. Wish it was more palatable. 

Blending is definitely an option.  

Hard to tell, since you are not using terminology that most of my friend distillers would employ. Alcohol burn is something very different from the "heat" of a new-make spirit: the latter will mellow with aging, the former changes ONLY with proof, or by being overpowered by other flavors. Are you tasting at 57%? I would expect anything over 100 proof to taste very alcoholic. Does that "heat" go away if you proof down to 80? Generally, I don't consider smooth the opposite of hot.

[Al The Chemist]

@DrDistillation Thanks for the tips. I did bring the spirit down to 80 proof and let is rest. It did improve the issue somewhat, but not to the extent I would hope. Question about the glycerin. Is the goal added body (mouth feel viscosity) or to add sweetness? The spirit has quite a bit of body from the tannin in the barrel. 

 

@bluestar, apologies for the lack of terminology accuracy. I'd be happy to dial in on the difference for future. What are you referring to by heat? From what you're saying, I'm referring to alcohol burn.

As for proof, I tried it at both 110 and 80 proof. The 80 proof was more palatable. Though the rum was FAR less "notably alcoholic" going into the barrel. And there was very little difference in abv. 

[DrDistillation]

Glycerin is a viscous liquid that is sweet-tasting.  So you are adding some body as well as a tad of sweetness.  However you are adding such small amounts (if done right) it won't be apparent but will be just enough to add a slight bit more body (different from tannin) and just a smidge of sweetness that will help as well.  It's something worth trying as you only need a couple buck bottle of glycerin and a shot glass or two of spirit to play with.

Some/many people add glycerin to vodka like products.

[FaintingGoatSpirits]

4 hours ago, DrDistillation said:

Glycerin is a viscous liquid that is sweet-tasting.  So you are adding some body as well as a tad of sweetness.  However you are adding such small amounts (if done right) it won't be apparent but will be just enough to add a slight bit more body (different from tannin) and just a smidge of sweetness that will help as well.  It's something worth trying as you only need a couple buck bottle of glycerin and a shot glass or two of spirit to play with.

Some/many people add glycerin to vodka like products.

People add glycerin to their vodka? Wouldn't you have to add that to your label?

[DrDistillation]

Some countries require it be on the label but the TTB does not if under a specified amount.

[bluestar]

On 4/26/2020 at 3:01 PM, Al_The_Chemist said:

@DrDistillation Thanks for the tips. I did bring the spirit down to 80 proof and let is rest. It did improve the issue somewhat, but not to the extent I would hope. Question about the glycerin. Is the goal added body (mouth feel viscosity) or to add sweetness? The spirit has quite a bit of body from the tannin in the barrel. 

 

@bluestar, apologies for the lack of terminology accuracy. I'd be happy to dial in on the difference for future. What are you referring to by heat? From what you're saying, I'm referring to alcohol burn.

As for proof, I tried it at both 110 and 80 proof. The 80 proof was more palatable. Though the rum was FAR less "notably alcoholic" going into the barrel. And there was very little difference in abv. 

Definitely NOT alcohol burn. That is either just a function of proof, or of balance between proof and other flavors in the profile. Heat usually is a result of residual ketones.

[DrDistillation]

On 4/26/2020 at 4:01 PM, Al_The_Chemist said:

@DrDistillation Thanks for the tips. I did bring the spirit down to 80 proof and let is rest. It did improve the issue somewhat, but not to the extent I would hope. Question about the glycerin. Is the goal added body (mouth feel viscosity) or to add sweetness? The spirit has quite a bit of body from the tannin in the barrel. 

 

@bluestar, apologies for the lack of terminology accuracy. I'd be happy to dial in on the difference for future. What are you referring to by heat? From what you're saying, I'm referring to alcohol burn.

As for proof, I tried it at both 110 and 80 proof. The 80 proof was more palatable. Though the rum was FAR less "notably alcoholic" going into the barrel. And there was very little difference in abv. 

Just curious.

How did things turn out?  What did you end up doing?