Vodka chemistry

[NeoPTLD]

From what I understand, Vodka is basically a plain, dilute solution of ethanol, however they range considerably in price and the difference is usually in the smoothness.

Visiting Skyy site, they describe that their vodka has the lowest impurities among the leading vodka brands.

Copied from their site,

"Vinquiry, an independent certified lab, concluded that SKYY has the fewest impurities among leading vodkas. Samples of SKYY, Absolut, Stolichnaya, Grey Goose, Smirnoff, Belvedere, and Ketel One were gathered in October 2002 from six major U.S. metropolitan areas. Using a precise Gas Chromatograph, the lab tested for the following impurities found in spirits: Methanol, Acetaldehyde, Ethyl Acetate and Fusel Oils. To view the comparison chart that graphs the results, launch the Flash version of the site."

They implicate that more impurities will deliver a less smooth final product.

Copied from Skyy FAQ page:
"Do traditional pot stills produce better vodka?

-Using antiquated pot stills may create vodka with more impurities than the innovative methods pioneered by Skyy Vodka, thus delivering a less smooth final product."

I got this from the internet:

"Vodka, produced on a mulitcolumn distillation system from a fermented mash of grain at or above 190o proof, must be further treated with charcoal or activated carbon or further refined by distillation in such a manner as to be without character, aroma, or taste. If any flavoring material is added to the distillate, the vodka is characterized with the name of the flavoring material used."

I diluted some Everclear(95%) with distilled water to yield a final product that is around ~70 proof and compraed the smoothness side by side with some Skyy. Skyy was definitely smoother than the diluted Everclear. Is this so because of the impurities within the 5% balance of Everclear?


These are what I would like to know:

Is smoothness the result of absolute purity or is it a presence of certain impurities in right concentrations that masks the burning sensation? What are the impurities responsible for smoothness/burning sensation?

What impurities does activated charcoal remove and how does it select what to remove? As far as I know, it doesn't do something like removing methanol(something Skyy included in a list of impurities) from ethanol?

Would mixing HPLC grade undenatured pure ethanol with distilled water yield the smoothest vodka ever?

 

[Gibsons]

Some info here, click on 'distillery tour.'

 

[DrPizza]

This probably doesn't help to answer your question, but IIRC, one of the impurities, amyl alcohol, is responsible in some alcoholic products for hangovers.

 

[imported_ssm0002]

I read a web blog where some people took the cheapest Vodka they could find, ran it through a Britta filter several times and said it tasted as smooth as Skyy. Conclusion: The better Vodka's are filtered a lot more than the cheap stuff. YMMV.

 

[NeoPTLD]

Originally posted by: ssm0002
I read a web blog where some people took the cheapest Vodka they could find, ran it through a Britta filter several times and said it tasted as smooth as Skyy. Conclusion: The better Vodka's are filtered a lot more than the cheap stuff. YMMV.

ummm ok? Relating to a trial and error method doesn't answer my question regarding the underlying chemistry.

 

[Gibsons]

Ok, since no one seems to have a definitive answer, I'll throw out some vague suggestions

Some impurities could be --

methyl alcohol
acetaldehyde - byproduct of ethanol
acetic acid - byproduct of ethanol
propyl alcohol
"congeners"- this is a generic term given to odd compounds that seem to give hangovers. Probably responsible for a lot of the taste in many alcoholic beverages. But it's hard to get a good read on what they actually are from Googling. Apparently carbon (activated charcoal) can be effective in removing some of them according to http://health.howstuffworks.com/hangover3.htm

One thing that seems safe to say is that most of the impurities should have a boiling point fairly close to that of ethanol.

 

[pm]

I've noticed this with Cognac as well. Some are very smooth, some are harsh. Since Cognac is a blend of grapes made into wine, distilled and then spends a lot of years in a barrel it probably has a huge variety of impurities... but I have wondered for a while what makes one Cognac taste smooth and another one, made using the same process and the same materials, harsh.

I just know which ones that I like... it's a bummer all the good ones cost a lot of money though. Although, since I only have one small glass every now and then, even premium VSOP Cognac is a heck of a lot cheaper than my Starbucks addiction.

 

[Crusty]

Originally posted by: ssm0002
I read a web blog where some people took the cheapest Vodka they could find, ran it through a Britta filter several times and said it tasted as smooth as Skyy. Conclusion: The better Vodka's are filtered a lot more than the cheap stuff. YMMV.

I've done the same thing, it didn't make a difference. After filtering it 10 times, the Grey Goose was still MUCH smoother.

 

[Tiamat]

You dont want to be using lab grade ethanol. In order to break the 96% or so Azeotropic composition, you have to either use pervaporation, or distill a ternary system. The most common way to make 99.99% pure lab grade ethanol is to distill a ternary mixture including Benzene, water, and ethanol. The trace benzene in Lab grade ethanol is not good for you at all.

 

[NeoPTLD]

Originally posted by: Tiamat
You dont want to be using lab grade ethanol. In order to break the 96% or so Azeotropic composition, you have to either use pervaporation, or distill a ternary system. The most common way to make 99.99% pure lab grade ethanol is to distill a ternary mixture including Benzene, water, and ethanol. The trace benzene in Lab grade ethanol is not good for you at all.

Anhydrous alcohol is different. There is ~95% ish lab alcohol out there.
How about synthtic alcohol derived from petroleum source? (catalyzed hydration of ethylene gas to ethanol). It should be free of all the fermentation impurities such as fusel oil.

 

[CycloWizard]

Originally posted by: NeoPTLD
Anhydrous alcohol is different. There is ~95% ish lab alcohol out there.
How about synthtic alcohol derived from petroleum source? (catalyzed hydration of ethylene gas to ethanol). It should be free of all the fermentation impurities such as fusel oil.

Maybe things have changed in the last 5 years or so, but what SKYY says on their site should not be true. Alcohols intended for human consumption are legally required to be fermented naturally. This is specifically intended to avoid the contaminants that they list on their site, particularly methanol, which can be extremely harmful to humans.

Activated carbon (charcoal) removes many impurities. It will particularly go after impurities that are hydrophobic (non-polar), which is why it's good for purifying alcohol-water mixtures. The exact nature of this process is undoubtedly proprietary, and I doubt you'll get the answers to your questions from anyone here. The people at SKYY are the only people who will know the details of how it works, and I'm guessing they won't tell you either.

 

[Rhin0]

Since you top off at 95% (as mentioned) traces of Benzene are usually present. Has to do with the process to break the ~95% barrier. Among other things that were mentioned.

YUMMY YUMMY BENZENE

 

[thereaderrabbit]

This whole azeotrope conversation seems like side issue to me (because it can not be safely avoided... unless you use extreme measures ) While this prevents you from making a pure high proof alcohol, it is not the only way to improve smoothness (or reduce a hangover).

As far as a hangovers goes- yes, there can be some nasty impurities in the conversion of sugars to alcohol, but good technique is the best way around this. I would think that a combination of ingredients, fermentation technique, and proper storage would be the leading factors in solving this problem while making a drinkable product. I believe it is also these three factors that the liquor companies are most hush-hush about, and lead to some brands being able to charge more for a smoother product.

I think Gibsons is off to a good start in naming common nasties. Also, nasty byproducts probably vary from producer to producer, thus a Brita filter could help in some cases, but I doubt that makes things all that much better.

-Reader

 

[iwantanewcomputer]

Originally posted by: ssm0002
I read a web blog where some people took the cheapest Vodka they could find, ran it through a Britta filter several times and said it tasted as smooth as Skyy. Conclusion: The better Vodka's are filtered a lot more than the cheap stuff. YMMV.

i tried this through a PUR filter 6 times with $8 a liter 80 proof alcohol and it noticably helped the tase, but it still was very bad, not worth it

 

[wadewood]

Vodka - Vodka is a grain neutral spirits; GNS. This means it can be made from fermenting any type of grain; wheat, corn, rye, grapes, etc. In the United States, Vodkas are defined by U.S. government regulation as "neutral spirits, so distilled, or so treated after distillation with charcoal or other materials, as to be without distinctive character, aroma, taste or color."
Vodka has to be distilled to 190 proof. By distilling to 190 proof, most all flavor characteristics are removed. Water is added to reduce the 190+ proof GNS to between 100 and 80 proof for bottling. Post filtering and adding water to product is really the only differences in brands of vodka. Flavored vodkas are nothing more than regular vodkas that have flavor additives put in after distillation process.
The hype you read on vodkas about being distilled 5 times and filtered 14 different ways is just that, marketing hype. Vodkas producers are putting their products in tall skinny bottles so they will not fit on lower shelf, forcing bars to place them on ?top shelf?.

Myself, I like flavor and drink Kentucky Straight Bourbon.

 

[NeoPTLD]

But the thing is...

Expensive vodka and watered down everclear DO NOT taste the same.

 

[M00T]

Scroll down to the pictures

 

[NeoPTLD]

Originally posted by: M00T
Scroll down to the pictures

That is not informative at all. We know people do this. It's absolutely useless unless they provide gas chromatography analysis for before and after.

 

[M00T]

Or you find out what particles could possibly be filtered out by the brita. No need for a complete analysis. I doubt you'll find an AT'er with a spectrometer laying around. Ask your chem prof to let you do an experiment.

 

[Changlinn]

The filtration idea does make sense, activated carbon is known to be a good absorber of odors, and noxious chemicals... next time I make my homemade lemon squash and vodka I am gonna have to filter it first.

 

[nyarrgh]

Originally posted by: ssm0002
I read a web blog where some people took the cheapest Vodka they could find, ran it through a Britta filter several times and said it tasted as smooth as Skyy. Conclusion: The better Vodka's are filtered a lot more than the cheap stuff. YMMV.

I read that too... TechTV's Screensavers (when they were still half-fun) recreated that experiment with 10 Britta filters one on top of the other, and a hole poked at all the bottoms except for the bottom filter. They SAID it helped, I've never tried it though. And I don't watch the screensavers anymore, but that's a different story.