Rapid Deterioration of Poured Bourbon

[bluesbassdad]

Last night I noodded off in front of the TV. (It's easy to lose track of time while watching the continuous coverage of the war.) Before I zonked, glass in hand (I didn't spill a drop while I napped ), I drank about three quarters of a generous pour (2-3 ounces) of Corner Creek in an EWSB rocks glass.

When I awoke a couple of hours later, the remaining bourbon had turned cloudy. It tasted funny, too, but that could be because of the condition of my mouth after sleeping a while.

Does anyone know what sort of change took place? Why would this bourbon undergo a change so significant in such a short time when I've had others hold up after sitting out all night?

Yours truly,

Dave Morefield

[boone]

It's called "flock"...

Distilleries "Chill Filter" their bourbon before bottling to remove the flock...the general public will not drink it when flock has occured...There have been several discussions about this...I don't recall which forum that it's in...

Heaven Hill chill filters...others who "say" that they don't...well...they add tremendous amounts of carbon to their bourbon to prevent flock...That is straight from the "Chief" (Mike Sonne) of the Lab...at Heaven Hill Distilleries, Inc...

Bettye Jo

[bluesbassdad]

Bettye Jo,

Thanks for your reply.

I was under the impression that the appearance of flock is triggered by cool temperature. Am I mistaken about that? I didn't have the heat on last night, but I'm pretty sure that the indoor temp didn't drop below 65 degrees F.

I also recall that haze or flock does not occur in higher proof bourbons, those 100 proof and above, IIRC. If that is so, then perhaps the temperature at which flock occurs varies depending on how low the proof is.

I think someone suggested that Corner Creek's tinted bottle may have been adopted to hide the haze from the customer's view (or, to put it more positively, to allow it to be bottled and sold with all its flavor still inact). I wonder whether it is more prone to haze than other bourbons of similar proof. Could it be that wheaters are flockier than rye recipes?

I'll do a search, and maybe I'll find the answers to some of my questions.

BTW, you mentioned adding carbon. Wouldn't that violate the law regarding the purity of bourbon?

Yours truly,

Dave Morefield

[bluesbassdad]

Bettye Jo,

You are right; this topic has been discussed before at length in at least two threads, "Charcoal Filtration" and "storage of Bourbon".

After skimming those threads I'm still not sure whether there's something different about Corner Creek (and wheaters in general) in regard to flock.

I didn't see anything about how cold it has to get before flock appears, either. However, you mentioned in one of the above threads that Heaven Hill filters at 17 degrees. I would guess that's the temperature at which nearly all of the amino acids that cause flock will conceal, allowing them to be filtered out. That leaves unanswered the question as to what temperature causes the onset of flock.

Yours truly,

Dave Morefield

[jeff]

Dave,

I notice this every once and a while when I leave an unfinished glass of bourbon next to the computer overnight. I guess it could be "flock", but I rekoned that it was from evaporation of the water in the bourbon, leaving behind the impurities, tannins, cogeners, etc...

[Gillman]

Funny, I have never had this experience. When I leave a dram (sorry, but this Scots talk works) overnight, it never clouds although in most cases I cover the glass with a saucer, so that may explain it.

Where I notice flocculation is when I mix whiskies, even of the same type (e.g. this occurred when I mixed George Dickel regular with the older, 10 year old). There must be something about different whiskies, or rather their combination, that causes deposits to be made that otherwise would not occur.

I don't know why this is. I do know that volatility (e.g. of congeners) can change if whiskey is mixed with water or steam. What happens is, the temperature at which some congeners will become volatile is altered when distillate (at least) is mixed notably with water. This is the principle of extractive distillation as applied to whisky, and is a Canadian standard method (as the middle distillation of three typically done) to remove what are regarded as undesirable flavours.

Could air getting into straight whiskey lead to congeners leaving the mixture, thus affecting its clarity? I don't know..

Is there a chemist in the house..?

Cy

[boone]

Chris (our chemist) was gone Friday...I need to get in there early...He works first and I work second...I was going to ask him about the sulfites in bourbon...I will ask at what temp. does flock occur...I don't know the answer...

I have experienced flock in a entire (filled bottles) line of bourbon...I had to pump it all back and start another order...I wondered why it happened because the temp. in the bottlinghouse was close to the temp. in the tank room...not a great deal of difference...I did not ask why...I just fixed the problem on the line and went on...

I asked the same question about carbon...and he told me...if they are not chill filerting they are adding extreme amounts of carbon...We chill filter...he said and I QUOTE...I would rather filter, instead of adding carbon to it--He also told me that they will do one method or the other...or run the risk of all the bourbon being returned...the average consumer will not buy, much less drink bourbon that has flocked...

I will ask your question on Monday...

Jeff---the white residue that is left in the bottom of the glass is flock...you cannot filter all of it out...

Bettye Jo

[Gillman]

Thanks, Bettye Jo, and I wonder if the chemist might have an opinion on whether it is possible to clarify whiskey that has gone cloudy but won't clear naturally (ie. by gravity). I have some bottles two or three decades old that are milky cloudy, the kind of flock you referred to. This flock holds in suspension. I wonder if it is possible to add something to precipitate down that flock? The Byrn distillation book (1875) suggests adding "alum" to spirits to clarify them. I am not sure what alum is, how to find it, or whether it would work.. This whiskey tastes okay, but as you said, it is off-putting to drink a noticeably cloudy beverage. Thanks for any suggestions he may have.

Cy

[cowdery]

I've read the other responses and while flock may account for the cloudy appearance, it doesn't account for the taste change. That's oxidation. (I hesitate slightly, because I'm not a chemist, but I'm pretty sure I'm right.) Also, in that situation (open glass) the alcohol should (again, chemists should feel free to correct me if I'm wrong) evaporate before the water, it being more volatile. The alcohol component of any beverage alcohol is "pure" (i.e., alcohol is alcohol) so the "other stuff" is in the water portion, which is left behind when the alcohol drifts off.

I say all this with slightly less confidence than I usually feel, but I think I've got it more or less right.

Plus, Dave, you probably drank more of it than you think you did. (I know I always do.)

[boone]

I made a print out of your post and Chuck's post...I will ask him tomorrow...

The flock I'm talking about occurs with the temp...not time...

Oxidation is what happens through time and not a good seal?...Shoot far, I ain't a chemist. But I know where one is and I'll fetch him for ya.

Here in Kentucky...a lot of us would gag choke and puke before we would drink any of that stuff...

Bettye Jo,Kentucky back room--Chemist speakin' in layman's terms

[CL]

Heck, when I pour Stagg, it's me who has the rapid deterioration.

[bluesbassdad]

IIRC, alum is the common name for aluminum sulphate.

As a kid in the 1950's I was familiar with alum because of its role in relation to the flat-top haircut. To get the hair to stand up the barber would rub in shaving soap and then rub an alum block over it. The combination of the two substances produced a sticky substance that made even the finest hair rigid. (Butch wax was for sissies. )

I also recall that it would make one's mouth pucker if you could con someone into tasting it.

I just did a google search on the chemical name, and at least one hit regarding its role in water purification came up. There may be some connection between that and your reference regarding whiskey.

Yours truly,

Dave Morefield

[cornsqueezins]

Dave, you were mentioning flock not occurring in higher proofed bourbons. By "flock", are we talking about a haze produced in bourbons ONLY at ambient temperatures?

I've added ice to Booker's before and witnessed an almost immediate clouding effect. Of course Booker's, though higher proofed, is also unfiltered so maybe that explains that particular phenomenon.

But there's one sure-fire way to prevent flock in a drinking glass. Finish your drink! Gadzooks!! I can't believe some of you people are not finishing your bourbon!

-Troy

[tdelling]

More information than you wanted to know, from an opinionated,

chemistry-minded straightbourbon participant (me):

Flock in beer/wine is generally polyphenols (tannins) precipitating with

proteins. There are many ways to handle this. Chill filtering is often used,

but so are "fining agents" which will clarify the drink by grabbing up the

things that might precipitate out on you. Silica gel is often used to grab

the proteins, and polyvinylpyrrolidone is often used to grab the tannins.

Sometimes, wineries will add tannic acid to increases tannin content (which

is sort of cheating) and precipitate out any excess protein.

There's not a lot of protein in aged bourbon, but there is a lot of tannin.

Tannins polymerize over time (this is a large part of what aging wine

accomplishes), thus producing a distribution of sizes of the molecules.

Some are longer, some are shorter. Each length has a different solubility

depending on alcohol concentration and temperature. Thus there is no

single temperature at which haze forms. It does form more easily at

lower temperatures and at lower alcohol concentration, so decreasing

either of these will cause haze. Since consumers expect a clear beverage,

manufacturers will generally chill filter to a temperature as low as they think

the bottle will be taken... basically you keep reducing temperature until you

stop getting complaints. It is possible to use a sufficiently high alcohol

concentration that it isn't neccessary to chill filter, becuase no haze will form

no matter how low the temperature.

There are those among us who have tasted, side by side, whiskies before and

after chill filtration. Does it remove flavor? Yes. As a matter of fact, both beer

and wine are often made beautifully crystal clear at the expense of taste. I'm sure

most of you have tried such drinks. I'm not 100% against all chill filtration... it

probably helps round out the whisky sometimes. I am against chill filtering when

it degrades flavor, but it's rather difficult to educate consumers about haze, so

the manufacturer is in a bind. I think the solution is to bottle at high proof so that

chill filtration is not neccessary.

Oh, what happened to your Corner Creek? The proof probably went down,

decreasing the solubility of some of the tannins, which then precipitated out.

I'm not sure whether they could be brought back into solution by adding pure

ethanol or not... perhaps I'll try it myself sometime.

Tim Dellinger

[boone]

Thanks Tim, ya saved me a early trip into work today

Bettye Jo

[bluesbassdad]

</font><blockquote><font class="small">In reply to:</font><hr />

By "flock", are we talking about a haze produced in bourbons ONLY at ambient temperatures?

[bluesbassdad]

Tim,

Thanks for the explanation. You make chemistry sound almost interesting. Maybe if you had been my prof, I wouldn't have failed quantitative analysis. (Then again, maybe it was my attitude at the time that was mainly to blame. It wouldn't be the only time.)

As to my cloudy Corner Creek, I think Chuck and you together have provided a likely answer. As he said, there was probably less bourbon in the glass than I originally estimated. The ratio of surface area to volume was very high, which magnified the effect of evaporation on the remaining liquid. The fact that I held the glass in my hand, sleep notwithstanding, for about two hours probably warmed the bourbon well above room temperature causing significant evaporation of alcohol. The lower concentration of alcohol, not a change in temperature, was probably what caused precipitation to occur.

Yours truly,

Dave Morefield

[tdelling]

I should probably also add that there are a lot of other oak-derived goodies in there, too,

which vary in size and chemical composition, and thus solubility. Haze probably has

some lignins and hemicellulose all mixed up in there with the tannins.

Tim

[Gillman]

Very valuable thoughts. Any ideas why the haze would form in liquor long stored? Is the explanation the same?

Cy

[tdelling]

>Any ideas why the haze would form in liquor long stored? Is the explanation the same?

Well, it's the same general process. Sometimes it just takes a while for things to

precipitate out.

Tim

[Gillman]

Tim, many thanks, but here's the follow up: is there some way in a home environment one can reverse that clouding, I mean in bottles long stored?

Cy

[tdelling]

> is there some way in a home environment one can reverse that clouding,

> I mean in bottles long stored?

I don't know. I've never tried it, and I've never really asked anyone about

it, either.

Personally, I don't see it as a negative thing. It's perfectly natural. As a matter

of fact, I consider it a bit of a mark of quality, in a strange way. It means that

they didn't filter the living heck out of the drink, so there are more goodies in

there.

I have no idea whether haze is reversible. The usual solution is either to

filter the liquid, to rack it off, or (if you've got a big operation with lots of cash and

can afford the thing) to use one of those newfangled centrifuges that the big

breweries and wineries have. That's all done before the liquid is bottled, though.

Once it's in the bottle... well, I can only guess. My only two thoughts

are the obvious ones: heat or more ethanol. When sugar crystallizes out of

jelly or honey, you can heat it up to dissolve the sugar again, and that

works for a while. I don't think that either heat or more ethanol are really

a good idea, though. I'd say it's best just to leave it alone. If it's really burnin' your

biscuits and you can't stand to look at the stuff, then you might try

filtering or decanting it, and then pouring it back in the bottle.

Tim

[Gillman]

Tim, thanks for this, sorry for late reply.

The haze in my bottles, all partly evaporated, is held in suspension.

I may try light heat to clarify them.

I think Chuck said if the alcohol lifts off, the remaining water-heavy mixture will cloud more readily. Why is that though? Why would the precipitate be more likely to manifest in a solution richer in water than alcohol..?

Cy

[cowdery]

I think we're dealing with a couple of different phenomena here. Flock is a haze that appears at low temperatures. What Dave originally described was a liquid from which some of the water and even more of the alcohol had evaporated, which was exposed to the air for several hours, and which had previously been exposed to Dave's saliva and who knows what else, and it got a little cloudy. I imagine volatiles vanishing and solids, including some deposited by Dave, remaining.

I apologize for bringing Dave's bodily functions into this, but there it is.

[Gillman]

Thanks, I think you're right, also perhaps even the cleanest glass has some soap or other residue and that may get in too. There must be more than one thing happening because Bettye Jo said when some whiskey is prepared for bottling it will cloud regardless of its temperature. I know that many people feel excess filtration can harm whiskey flavour in that the proteins, etc. taken out can affect flavour although bourbon is so robust this shouldn't matter too much. But sometimes filtration makes flavour better. I know this from my blending experiments. Mixing different whiskies can as I said precipitate out faster tannins and wood-derived extracts and those particles can mask flavour (a bit like an over-yeasty beer can) so it is good to get them out. This kind of haze just drifts down by gravity. I am sure all this is understood by the chemists in the industry. I was reading the other day a description of how congeners are removed from spirit and the organic chemistry is mind-boggling, they know to a polymer strand what affects flavour and just how to distill to get the degree of taste wanted, depending on what type of spirit is being made (straight whiskey, light whiskey, neutral spirit, etc.). An awesome science, but it still is an art too. To take one example, Barton's Very Old is one of the most methodically-made bourbons from what I have read but is still (maybe because of?) fine, aromatic whiskey. Barton Brands know exactly the character they want to get and do a great job. BVO has to be about the best value spirit in America and even their blended whiskeys are top-notch.

Cy