View Full Version : Evaporation/concentration of old bourbon
I visited the Bourbon Festival in Bardstown, KY a couple of months back. While touring the Getz Museum and attending an auction where prohibition-era bourbon was up for bid (some that had been distilled as early at 1917), I noticed that many of the older bottles appeared to be as little as half empty. While these bottles were sealed, sometimes in wax, I believe that this apparent loss of was due to slow evaporation over the years. Is this correct? Also, some of the bottles that were quite empty (i.e., about half) looked cloudy. Would this be due to these bourbons not having been filtered (and subsequently subjected to cold temperatures), or is it due to a concentration and subsequent release of some of the soluble matter in the whiskey?
I guess these questions ultimately lead to another question: If these bourbons have been "concentrated" by evaporation, how would they taste? At the auction I attended, they commented that the Van Winkle family had been given a bottle the evening before of one particular brand -- they opened it and let everyone sample some -- and apparently the bourbon was quite good (and different from "modern" bourbon). The bottles they pointed out did not appear to have suffered too much from evaporation (at most 1/4 to 1/3 of the liquid). Is there some sort of event horizon whereupon a bourbon no longer tastes good because it has been concentrated? Or, could the "different taste" of the older bourbons that had evaporated some be the result of some of this concentration (thus indicating a sliding scale of flavor)?
I was just wondering. Being a law student (and on a very fixed income), I didn't really have the resources available to bid on any of these bottles (none going for less than $60-70), but I do have an avid interest in the topic.
DirtyCowboy wrote: "I believe that this apparent loss was due to slow evaporation over the years. Is this correct?"
Either evaporation or leakage.
DirtyCowboy also wrote: "Some of the bottles that were quite empty (i.e., about half) looked cloudy. Would this be due to these bourbons not having been filtered (and subsequently subjected to cold temperatures), or is it due to a concentration and subsequent release of some of the soluble matter in the whiskey?"
Filtering would be a factor. Don't know what soluble matter would be released by "concentration." The cloudiness could also be contamination of some sort.
DirtyCowboy also wrote: "If these bourbons have been 'concentrated' by evaporation, how would they taste?"
That much loss means a lot of oxidation has taken place. They probably would not taste good. If, however, a bottle is well sealed and very little evaporation has occurred, the whiskey can taste very good. Kept properly, the whiskey shouldn't change one bit.
With whiskey, I don't know if "concentration by evaporation" is really a useful concept. Both the alcohol and the H20 will evaporate. What doesn't?
DirtyCowboy also wrote: "Apparently the bourbon was quite good (and different from "modern" bourbon)."
I have tasted pre-prohibition whiskey. "Different" doesn't necessarily mean better. Process controls back then weren't what they are now so there was more variation from batch to batch. People who have tasted more of it than I have say that's the main difference you notice. Most of what you might taste in a pre-prohibition whiskey that you wouldn't taste today is stuff you wouldn't want to taste.
Pre-prohibition bourbon is rare, but not as rare as you might think. The prices you quoted are proof of that. While $60-$70 a bottle is a lot to most people, it is chump change in the world of rare scotch or cognac.
I am interested in hearing more about that auction. Did anyone else attend?
Thanks for the input.
But a little more...
> With whiskey, I don't know if "concentration by evaporation" is really a useful concept. Both the alcohol and the H20 will evaporate. What doesn't?
There is soluble matter in the whiskey: sugars, etc. leeched from the wood during againg. That is what produces the flavor and color in whiskey (technically, H20 and Alcohol have no flavor or color -- e.g., with very good and pure vodka). That is what I was thinking would concentrate as the water and alcohol evaporated.
> Pre-prohibition bourbon is rare, but not as rare as you might think. The prices you quoted are proof of that. While $60-$70 a bottle is a lot to most >people, it is chump change in the world of rare scotch or cognac.
Unfortunately, as a law student, I'm lucky if I can afford a bottle of Woodford (though living in Kentucky makes this much easier to do -- I've heard that
stuff going for as much as $40 a bottle elsewhere -- it's only $25 here).
Regardless, the auction was incredibly interesting. They also auctioned off several "export only" items. One in particular was a 23 year old version of Pappy Van Winkle with a black seal and black velvet bag. I forget how much it went for (but I'm pretty sure it was in the hundreds of dollars arena). BTW, if you've never tried Pappy (I know it's expensive), try it as soon as you get a chance. It's incredible. If you attend the Bourbon Festival, they will probably have a bar where you can try it (along with several others -- this year they premiered Buffalo Trace, which was also quite good). And if you are going to be in KY for the festival, may I recommend a side trip to Lexington to visit Nicholson's Cigar Bar. They have an enourmous selection of
whiskey (supposedly including every type of bourbon available domestically).
Thanks for the info,
Saw your inquiries posted. The old whiskey that my family got at the Bourbon Festival was "Bankers & Brokers". The Japanese were pretty strong bidders at the auction. I think I remember someone writing down the prices for all the items at the action. I'll look into it. The "B & B" bourbon was distilled by my grandfather(Pappy) at the Stitzel-Weller Distillery in 1937 and bottled in 1941-thus 4 years old. The whiskey was still in incredible shape for its age. I'm obviously a fan of older whiskey, but this was wonderful whiskey-even at 4 years old. Of couse it had something to do with the way the whiskey was made back then. I think if these older whiskeys are kept in good condition,(air tight), they will last qu
One of my other great passions is Single-Malt Scotch. There has been a large debate, especially in recent years, of over the coloration added after bottling.
The story goes: During Prohibition, the Americans began to filter their Bourbon before exporting it.
Unfiltered whisk(e)y clouds when subjected to cold temperatures. Filtered whisk(e)y does not cloud, but does lose its color. Americans claimed that this cloudiness proved the inferiority of Scotch. To compensate, the Scots began to filter their whisk(e)y and add color to make up for that which was lost.
This is a round-about way of saying that maybe the cloudiness of the Bourbon is because it is unfiltered.
I don't know about this color loss business. Chill filtering was explained to me like this. The finished whiskey contains some small amount of fatty acids which can, under certain conditions, produce a cloudy appearance. The effect is purely cosmetic, it has no bearing on the taste, smell or safety of the spirit, just its appearance. To remove these fatty acids, the spirit is chilled to 30-something degrees (I forget the exact temperature, but I think it's just above freezing), which causes the fatty acids to thicken and renders them incapable of passing through a finely woven silk filter. This filtration incidentally removes fine particles of wood and char, which may affect color slightly, but the purpose of the filtration is the removal of the fatty acids that cause clouding. No coloring is added to bourbon at this time or any other.
This type of filtration, which is done on virtually every bourbon made today (Booker's is one known exception), is to be distinguished from charcoal filtration, or leaching, which is done by Tennessee whiskey and some bourbons, which is done before barreling. This process has no effect on the afore mentioned fatty acids, so charcoal filtered whiskeys also go through the chill filtration process before bottling.
This is the line from many Scotch distillers. I never meant that they said all distilled spirits lose color when filtered. Scotch, however, does: something about the chemical makeup. While it does not become clear, it does lighten considerably.
Either way, the fact that unfiltered whisk(e)y clouds is not in question. Yes, cloudiness is only a cosmetic difference and does not affect the taste. I did not mean to imply otherwise.
I hope this clears up what I said. I was just trying to get to the bare bones of why the old, unfiltered Bourbon appeared cloudy.
I only chill filter anything I bottle below 100 proof. Anything above 100 proof, such as my Old Rip 107 proof, needs no chill filtering if you add good water to lower the proof from the barrel for bottling. If you pour this "unfiltered" whiskey over ice, sometimes it will cloud up. This, as mentioned, is only a cosmetic problem. Flavor is not compromised.
Anything I bottle below 100 proof, I chill to at least 18 degrees. This is to remove the cloud which may occur if the whiskey is subject to a cold environment, such as an unheated warehouse or shipping conditions in a truck. Maker's Mark does not chill filter since their whiskey is so young. I cannot get away with not chill filtering my lower proof wh
I am extremely skeptical of the sources who gave you this information. There are two types of filtration commonly used in the scotch industry. Chill-filtration, which you mentioned, and physical methods. Color in whisky is derived for the most part from particles which are collodial and so minute that a very expensive microfiltration or osmotic membrane would be needed to acheive any significant reduction. If this were done, the essence of the whisky would also be stripped.
The physical filtration of scotch whisky commonly employed only removes the "chunks" as you mentioned like cask lining, etc. The pore size of these filters is way too large to effect any noticeable color change.
Chillfiltration is a solubility process whereas certain molecules (mostly proteins) will form large chains and drop out of solution. There is no consensus that chillfiltration has no effect on the character of a whisky. In fact, there is a growing trend within the industry to produce enthusiast market (i.e. $$$$) products which are not chillfiltered. This is ironic since it is ultimately cheaper to produce these due to the lack of lost yield from the filtrate.
I also question the assertion that there is any chemical difference between scotch and American whiskey which would account for one being more susceptible to color loss due to routine industry practices. Caramel coloring is a common industry practice used to compensate for the batch differences from vatting to vatting of the casks used to comprise a bottling. It is also used to camouflage the apparent age of the whisky in the bottle. The consumer has been brainwashed to think that darker whiskies are older and older whiskies are better.
But hey, that's just my opinion.....
This information is from Iain Henderson, head distiller of Laphroaig.
Julian said to Dirty Cowboy...
...The old whiskey that my family got at the Bourbon Festival was "Bankers & Brokers". The Japanese were pretty strong bidders at the auction. I think I remember someone writing down the prices for all the items at the action. I'll look into it...
That was my wife, Linda, taking down the prices. I think there were a couple of "B&B"'s sold as part part of baskets, but two individual 1-quart bottles were sold, one at $40 and one at $65. There were also about a dozen other pre-prohibition bottles sold, at prices ranging from $50 for a quart of J.W. Dant from 1934 to $180 for a pint of Old Taylor made in 1917.
Now anyone reading this should bear in mind here that this was a *charity* auction, with proceeds going to the Getz Museum of American Whiskey History (which we all revere), so the prices tend to be somewhat inflated. As you can see, no one's likely to get real rich cornering the market on pre-prohibition bourbon :-)
(By the way, Cowboy, Julian modestly neglected to mention that he was the _sponsor_ of the auction and that it raised around $5,000 for the museum. Thanks, Julian!)
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