What makes a bourbon "hot"?

[Flyfish]

You might assume that alcohol is what gives bourbon its heat. But veteran tasters know you would be wrong. PHC at barrel strength, for example, has a lot less burn than Benchmark Old #8 at 80pf. So, there must be other chemical and/or esthetic factors that contribute to our perception of heat.

A corrolary: I think wheated bourbons tend to taste sweet because the underlying corn is not masked the way it is by the more pronounced spice of rye.

What accounts for heat if it isn't the alcohol? Any of you chemists or other bourbon geeks know what might mask the burn? (Unless, of course, I'm totally wrong and it is the alcohol.)

[Brisko]

I think tannin and other related wood compounds may play a role. If I'm not mistaken you can get a lot of tannin in immature whiskey as well as in over-aged whiskey. But that's just my guess. I'd love to hear an educated opinion.

[callmeox]

A lack of balance makes it hot.

[deathevocation]

I'm probably wrong but I generally identify "hot" with "cheap".

[HighHorse]

This weekend I had the pleasure of attending a function with David Perkins of High West. He brought with him some samples of the "heads" and "tails" from the distilling process. The "heads" in particular have powerful benzene-like tastes .. so strong that they're darn difficult to approach. A lot of bourbon and rye distillers cut the heads and tails from the process saving only the sweeter "middle" for the barrel. David - and others - utilize the entire run to capture the entire essence of the mashbill. When we watered down the head and got past the "heat", you could find some flavors in the heads and tails that otherwise would have been cut from the barrel. After that experiment, I'm pretty well convinced that these full-flavored runs carry a punch that's telegraphed immediately by the inclusion of "heads". That and Alcohol content.

[soonami]

What makes a bourbon "hot" is usually fusel alcohols, the congeners that are fermentation by-products which condensate with the alcohol. The reason the "heads" and "tails" from a distillate is culled is because these contain the isopropanol, acetone, butanol, benzenes, etc that have similar boiling points that ethanol. These are also the compounds that are much more likely to make you sick or hung-over the next day from over-imbibing.

[OscarV]

Good questio0n but I don't understand what HighHorse is saying.

You would think that hotness equals alcohol content but it's not.

I have had 80 proofers burn my tounge and 130 proofers that taste as sweet as caramel.

[Young Blacksmith]

Think of the distillation process as a bell curve. As the mash heats up, it releases chemicals, one of which happens to be alcohol. The heads and tails are what are at the up and down ends of the bell curve.

The idea sounds right to me, about the heads being more hot, having different chemicals in the distillate. Could explain some of the older dusty bottles that are variable, as they used more of a human hand back then VS. now.

[p_elliott]

I could be wrong on this so Chuck or John Hansell or someone like that jump in and correct me if I am. But aren't the heads and tails methanol? That's the stuff that's makes you go blind or can kill you?

Edited November 8, 2012 by p_elliott
Check spelling

[soonami]

Methanol has a boiling point of about 65 C, Ethanol is about 78C, so the heads likely contain some methanol, but the tails probably have very little of it.

Nice little article about how cuts are made by distillers to separate the heads, tails, and the desirable hearts:

In distilling parlance, the compounds in the wash that are not ethanol or water are called congeners. Some congeners such as acetaldehyde, methanol, and certain esters and aldehydes, have boiling points lower than ethanol, while certain other esters, the higher alcohols (fusel alcohols), and water, have higher boiling points than ethanol. This means the lower-boiling-point congeners come out in high concentration at the beginning of the distillation run, and the higher-boiling-point ones come out in high concentration towards the end of the run, leaving the ethanol as the most abundant compound during the middle of the run.

So, when distillation takes place in an artisan still, such as the reflux stills discussed above, the distillate that comes out is divided into three phases called: heads, hearts and, tails. The heads contain the unwanted lower-boiling-point congeners that come out at the beginning of the run, and the tails contain the unwanted higher-boiling-point congeners that come out at the end of the run. And, the hearts are the desired spirit.

Since whiskey is not distilled at a high-separation level, it means that each phase bleeds into the adjacent phase. That is to say, there‘s a considerable amount of ethanol in the heads phase, and there are late heads congeners at the beginning of the hearts phase. Similarly, there's a significant amount of early tails congeners at the end of the hearts, and there‘s a considerable amount of ethanol in the tails phase. The hearts are the whiskey, and whilethey are comprised mostly of ethanol and water, they have a delicate balance of late-heads and early-tails congeners that make up the flavor profile of the whiskey.

Edited November 8, 2012 by soonami

[HighHorse]

Soonami - what you are saying is pretty much spot on what David Perkins of High West was demonstrating to us this weekend. Young Blacksmith, David used the bell curve example exactly as you have. He brought samples of the first half of the heads to come off the still then the second half of the heads. Same with tails. We proofed it down so that it was potable and tasted them. There is no question that the "fingernail polish" distillants that boil early and are captured taste "hot". They also taste pretty nasty. However, when diluted .. you can .. much as when you get past the proof in any bourbon .. pick up on flavors. As David explained it, the amount of those "cogeners or contaminants" left in the barrel for years add to the overall flavor rather than detract from it and they are not there in enough quantity to make you ill. Certainly, if they were not diluted, they would be darn near deadly don't you think? As one of my old professors used to say: "The solution to pollution is dilution"!

Further to your point, Soonami, I asked David what kind of instrument he used to determine when to cut from the heads to the hearts, etc and he pointed at his tongue and simply said "taste!, it's still the best instrument when making good bourbon and rye".

BTW, almost everything David Perkins puts out for High West is bottled at 92 proof and some of them come on like a much higher proof tasting.

Edited November 8, 2012 by HighHorse

[HighHorse]

p_elliott - back in my early days I was told that any number of things could make you go blind!

Fortunately, none have come to fruition!

[Young Blacksmith]

So I understand how cuts would be made on a pot still, where you dump the mash and heat the whole thing, but how is it done with column stills? Where they are continually running the mash into the still on plates?

[HighHorse]

So I understand how cuts would be made on a pot still, where you dump the mash and heat the whole thing, but how is it done with column stills? Where they are continually running the mash into the still on plates?

I'm far from an expert on any of this business. If I understand the way it was explained by David Perkins, most of those continuous stills consist of six column stills. There's a beginning and end of the continuous process. The beginning is when they dump the mash into the still and the heads would be taken off at the beginning of the process. The end of the process is the same .. and taste .. or perhaps instruments would tell you when to cut the tails. I do recall him saying specifically that the heads are removed in the first column. The mash going into the first column has to come up to temperature (right?) and it would be there that you would get the less desirable byproduct.

Going back to the original question of what makes some hot and some not (regardless of proof) ... my thinking is that it has to be an ingredient other than alcohol .. so what else could it be? (It ain't turnip greens .. so it ain't pepper sauce!) I tasted the heads and the "heat" is definitely there.

I don't believe there is a magic chemical moment when all distillers cut the heads and tails so .. it's up to the Master Distiller. So each brand would have varying amounts of heads and tails involved in the making of their bourbon. Those that take less of the heads and tails would have the easier entry and little or no finish. I think that explains the PH2012, for example, that is pretty darn high proof but seems to be universally thought to be lacking in the entry and finish.

At any rate, at this point .. I'm in over my head. I would defer to any distillers who might weigh in. I respect David Perkins, who I reference here, because he has a chemistry background and he learned his craft from some of the masters .. specifically Jim Rutledge. That plus the fact that he brought heads and tails samples for us to taste - and that was a first for all of us at the event.

[B.B. Babington]

soonami is right on point. note also that the mash produces congeners, and different beers can have different results; some quite nasty.

[sailor22]

Those samples of heads and tails David shared really connected some dots for me as far as taste and "heat" is concerned. Turns out a lot of the flavors I have associated with interesting complex whiskey are abundantly evident in heads and tails. All of the burn I thought was from alcohol or proof in a pour is in fact a characteristic of parts of the heads and tails. It was always confusing to me that high proof Vodka had no burn and some 80 to 90 proof Bourbons seemed to have a lot.

It also helps clarify why some of the craft distilled juice is relatively simple compared to juice from the majors, perhaps they are aggressively cutting heads and tails and only barreling the less complex heart. It's not just the barrels.

He also mentioned oxidation as a big part of the melding of flavors in aging. That's time, larger barrels and patience.

Still need someone to help me understand the way a continuous column still works and how the different plates used control the amount of each part of the process that is in the finished product.

Edited November 10, 2012 by sailor22

[tmckenzie]

I'm far from an expert on any of this business. If I understand the way it was explained by David Perkins, most of those continuous stills consist of six column stills. There's a beginning and end of the continuous process. The beginning is when they dump the mash into the still and the heads would be taken off at the beginning of the process. The end of the process is the same .. and taste .. or perhaps instruments would tell you when to cut the tails. I do recall him saying specifically that the heads are removed in the first column. The mash going into the first column has to come up to temperature (right?) and it would be there that you would get the less desirable byproduct.

Going back to the original question of what makes some hot and some not (regardless of proof) ... my thinking is that it has to be an ingredient other than alcohol .. so what else could it be? (It ain't turnip greens .. so it ain't pepper sauce!) I tasted the heads and the "heat" is definitely there.

I don't believe there is a magic chemical moment when all distillers cut the heads and tails so .. it's up to the Master Distiller. So each brand would have varying amounts of heads and tails involved in the making of their bourbon. Those that take less of the heads and tails would have the easier entry and little or no finish. I think that explains the PH2012, for example, that is pretty darn high proof but seems to be universally thought to be lacking in the entry and finish.

At any rate, at this point .. I'm in over my head. I would defer to any distillers who might weigh in. I respect David Perkins, who I reference here, because he has a chemistry background and he learned his craft from some of the masters .. specifically Jim Rutledge. That plus the fact that he brought heads and tails samples for us to taste - and that was a first for all of us at the event.

column stills for bourbon and rye consist of one column and either a thumper or doubler or some combination of the 2. during startup you have a lot of water coming over, this is sent to either a low wine tank or the beer well. once it is running, it is running in such a way that all of what would be heads or tails are being vented off as in the case of high boilers or low boilers that would be tails in a pot still are refluxed off the beer heater back into the wine trays or rectifying trays if they are being used or can be sent back to the beer well, anybody who ever has toured four roses may have seen a stream of liquor falling into the beer well. during shutdown there is water coming over and they are sent to a tank. There really is no heads or tails cut. Only vodka columns have multiple columns, stills for rum and grain whiskey in Scotland are variations of a coffey still in they have a rectifying column after the beer column.

Edited November 11, 2012 by callmeox
Cleaned up the broken quote block

[tarheel]

The "heat" is the physical sensation caused by the dehydration occurring in your mouth. Ethanol does that well. However, as others have stated, depending on how precise the distillation is a bunch of other small molecules come over during the distillation. Some of these would not be expected to be very hydrophilic, like esters for instance, which are more greasy. However, some of them could be - such as other alcohols, acetone, etc......Acetone is one compound that just soaks water right up! I would guess that with cheaper pours, more of these undesired dehydrating congeners have not been removed via distillation and voila, you get your (undesired) burn.