What ingredients are responsible for making vodkas good or bad?

[NeoPTLD]

Vodka is basically distilled "grain neutral spirits" diluted to specified strength with water.


A fifth of Grey Goose vodka is $34.95
A fifth of Potters Vodka is $6.30

They are both approx 40% ethanol and approx 60% with the balance deciding the fate between expensive rubbing alcohol and a fine vodka.

What is the chemical makeup and amount of balance that separates good vodkas from bad vodkas?

 

[Crusty]

Quality of the water? Quality of the grains? Quality of the distilling process?

 

[silverpig]

small amounts of methanol?

 

[stevf]

fusil oil and other fermentation by-products - these are similar to alcohol so hard to distill out

 

[NeoPTLD]

Could you make top notch vodka from using synthetic ethanol derived from hydration of ethylene gas and blending it with the common distilled & deionized water?

 

[PolymerTim]

I think the answers above pretty much answer the question, but I needed to kill some time and typed up my own thoughts.

I won't pretend to know anything about making vodka except what I just read online:
http://www.essortment.com/food/makevodkahome_sbcy.htm

Looking at the method, it seems that pure vodka is intended to be simply a 40% aqueous dilution of ethanol. I would guess what separates the different brands is how close to the intention they actually get.

I do know a little bit about distillation from my chemistry background that might be helpful here. Essentially, vodka is made by fermenting a mash of carbohydrates and yeast followed by distillation and purification of the ethanol from that mash. This contrasts to many other alcoholic drinks where the mixture is usually filtered to remove solids allowing all the natural flavors from the mash to remain.

Distillation is simply a method of purification that boils a mixture and allows you to separate components out of the mixture based on their boiling point. You slowly increase the temperature and the lower boiling components usually come off first, followed by higher boiling points. So, if you want to distill ethanol with a boiling point of 78.4C, you could theoretically boil the mixture at ~77.5C to remove any lower boiling compounds such as methanol (the part that causes blindness, liver damage, and death!) and then increase the temperature to 79C to boil off the ethanol into a separate collector.

If you've noticed I've used a lot of conditions like "intentions" and theoretically", it is on purpose. In reality, there are many complications that lead to gray areas. As an example, some liquids, when mixed in the right amounts will form something called an azeotrope where both compounds will boil at a lower temperature than either would individually. Additionally, if the boiling process is too fast, you can have a range of temperatures in your boiling vessel and fast moving convection currents that can drive vapors and aerosols with multiple boiling points quickly over to your collector at the same time. This is why instructions say you should distill at least 3 times, always discarding the first and last bits you collect. Distillation is not perfect, but each time you distill, you increase your final purity (although azeotropes can put a stop to that if you have any in your system). As a final purification, it is commonly filtered through activated charcoal which is an excellent absorber of a variety of organic compounds that commonly cause odors and colors. The final step is the addition of a pure water to dilute the pure ethanol back to 40%.

So it seems that the deciding factor in quality is how pure the final ethanol/water mixture is. As for what the other things are that typically make it into cheap vodkas, I have no clue and would be happy to hear from others. But I wouldn't be surprised if it was a fairly complex mix of different chemicals.

 

[BladeVenom]

Better distillation and good filtering make a better vodka. I however prefer beverages with more flavor.

 

[Rudy Toody]

How long they age it might be the difference.

 

[Gibsons]

Originally posted by: Rudy Toody
How long they age it might be the difference.

Vodka isn't aged AFAIK. Aging is done to impart flavor (usually in barrels) which is the opposite of what's desired with vodka.

For the OP, when yeast ferments grains (or potatoes or whatever), there are lots and lots of things produced, many of which are organic molecules with boiling points close to that of ethanol. Some of these have a particular flavor, some help cause hangovers. The better vodkas have (in theory) less contamination of these due to more distillations and more careful distillation. Here's an abstract. Text

 

[silverpig]

n/m

 

[QuantumPion]

Originally posted by: NeoPTLD
Could you make top notch vodka from using synthetic ethanol derived from hydration of ethylene gas and blending it with the common distilled & deionized water?

Yes, but there are laws against it IIRC. Alcohol made for consumption has to be organically produced.

 

[gorobei]

filtering.
all the stuff that makes it rough vs smooth is filtered out by a long and involved filtering process that adds time and additional costs to production. the longer it takes = more expensive, the more steps and equipment for filtering = more expensive.

 

[CycloWizard]

There are a few things that impact the quality of any fermented beverage. The three things that separate one beer/spirit from another: the yeast species, the sugar(s) used, and the processing conditions. There are a bazillion and one different types of yeast, each of which will process the inputs (sugar mostly) into different outputs, so the yeasts used are often proprietary or even home-grown strains. The sugar is obviously also very important, though I'll admit I don't know much about what makes a good beer/spirit, since no one will tell you what sugar mixture they use. Finally, the processing conditions and even the processes themselves can turn a good beer/spirit into a great one by removing unwanted species, filtering the yeast (or not filtering it, as is sometimes done especially in expensive Canadian beers ), and even the temperature/pressure at which these things are accomplished. I could write a whole book on the last part, but I'm sure someone already has, so I'll leave it at that.

 

[PolymerTim]

Originally posted by: CycloWizard
There are a few things that impact the quality of any fermented beverage. The three things that separate one beer/spirit from another: the yeast species, the sugar(s) used, and the processing conditions. There are a bazillion and one different types of yeast, each of which will process the inputs (sugar mostly) into different outputs, so the yeasts used are often proprietary or even home-grown strains. The sugar is obviously also very important, though I'll admit I don't know much about what makes a good beer/spirit, since no one will tell you what sugar mixture they use. Finally, the processing conditions and even the processes themselves can turn a good beer/spirit into a great one by removing unwanted species, filtering the yeast (or not filtering it, as is sometimes done especially in expensive Canadian beers ), and even the temperature/pressure at which these things are accomplished. I could write a whole book on the last part, but I'm sure someone already has, so I'll leave it at that.

But don't forget that vodka is a distilled alcohol and, unlike most beers and wines etc, is not intended to have any remaining compounds from the processing other than ethanol and water. So the inputs and byproducts from fermentation would only be important if they are not fully removed. Of course, I think the point is that they are never fully removed so maybe the fermentation byproducts are important if they can either be more easily removed during distillation/filtration or leave a less obvious or obnoxious presence in the final beverage.

 

[phisrow]

If you take a look at the Brita filter vodka upgrade procedure floating around the interwebs, you will find further support for the "assorted distasteful organic compounds" theory; as well as directions for verifying this experimentally. (or using the scientific method as an excuse to get hammered on cheap vodka, your option)

 

[CycloWizard]

Originally posted by: PolymerTim
But don't forget that vodka is a distilled alcohol and, unlike most beers and wines etc, is not intended to have any remaining compounds from the processing other than ethanol and water. So the inputs and byproducts from fermentation would only be important if they are not fully removed. Of course, I think the point is that they are never fully removed so maybe the fermentation byproducts are important if they can either be more easily removed during distillation/filtration or leave a less obvious or obnoxious presence in the final beverage.

Stupid as it sounds, I would bet that cheap spirits are "cheap" because they don't use simple processing techniques like cold filtering. What is intended in vodka is not what happens, at least not in the cheap stuff. I have known many people who have filtered cheap vodka through activated carbon filters and report good results, though I don't really drink hard liquor myself (after two nasty incidents ), so I can't vouch for the effectiveness.

 

[NeoPTLD]

So, I filled two shot glasses full. One with good vodka, one with H.R.D. Left them them sitting around for a few days to let the alcohol evaporate.

The remaining water from good vodka was practically tasteless. The water from HRD vodka had a sharp, sour taste.

 

[FallenHero]

Originally posted by: NeoPTLD
So, I filled two shot glasses full. One with good vodka, one with H.R.D. Left them them sitting around for a few days to let the alcohol evaporate.

The remaining water from good vodka was practically tasteless. The water from HRD vodka had a sharp, sour taste.

I think a larger sample size would be in order, but I don't doubt that the results would be the same.

 

[sjwaste]

Originally posted by: CycloWizard

Originally posted by: PolymerTim
But don't forget that vodka is a distilled alcohol and, unlike most beers and wines etc, is not intended to have any remaining compounds from the processing other than ethanol and water. So the inputs and byproducts from fermentation would only be important if they are not fully removed. Of course, I think the point is that they are never fully removed so maybe the fermentation byproducts are important if they can either be more easily removed during distillation/filtration or leave a less obvious or obnoxious presence in the final beverage.

Stupid as it sounds, I would bet that cheap spirits are "cheap" because they don't use simple processing techniques like cold filtering. What is intended in vodka is not what happens, at least not in the cheap stuff. I have known many people who have filtered cheap vodka through activated carbon filters and report good results, though I don't really drink hard liquor myself (after two nasty incidents ), so I can't vouch for the effectiveness.

I can vouch for the effectiveness. We took a handle of Skol, which is probably the best vodka that still comes in a plastic jug, so we had a decent starting point. It's actually scored well on some blind taste tests against premium brands, but thats neither here nor there. We filtered it through a Brita and tasted after each. After about 3 times through, it wasn't getting any better, and it really did go down really, really smooth.

So we repeated with a handle of Aristocrat, arguably the worst that comes in a plastic jug. After about 5 times through, it was almost as good as the Skol. We think that if we switched filters to a new one and did it a couple more times, it would've been better. But at that point, we just wanted to drink the stuff

 

[BladeVenom]

Originally posted by: FallenHero

Originally posted by: NeoPTLD
So, I filled two shot glasses full. One with good vodka, one with H.R.D. Left them them sitting around for a few days to let the alcohol evaporate.

The remaining water from good vodka was practically tasteless. The water from HRD vodka had a sharp, sour taste.

I think a larger sample size would be in order, but I don't doubt that the results would be the same.

If you leave alcohol sitting out to evaporate sooner or later it's going to get bacteria in it that will turn it to vinegar. So all he found out was which one got infested first.

 

[dorion]

Originally posted by: BladeVenom
If you leave alcohol sitting out to evaporate sooner or later it's going to get bacteria in it that will turn it to vinegar. So all he found out was which one got infested first.

So someone distill some good vodka and some bad vodka and taste the left over water. Who has the tools and knowledge to do that without blowing things up.


*EDIT* better yet go with NeoPTLD's original idea and make some pure vodka that way.

 

[PolymerTim]

Originally posted by: sjwaste
I can vouch for the effectiveness. We took a handle of Skol, which is probably the best vodka that still comes in a plastic jug, so we had a decent starting point. It's actually scored well on some blind taste tests against premium brands, but thats neither here nor there. We filtered it through a Brita and tasted after each. After about 3 times through, it wasn't getting any better, and it really did go down really, really smooth.

So we repeated with a handle of Aristocrat, arguably the worst that comes in a plastic jug. After about 5 times through, it was almost as good as the Skol. We think that if we switched filters to a new one and did it a couple more times, it would've been better. But at that point, we just wanted to drink the stuff

I like this technique. I guess now the big question is which costs more money: the filters or the expensive vodka?

Originally posted by: dorion

Originally posted by: BladeVenom
If you leave alcohol sitting out to evaporate sooner or later it's going to get bacteria in it that will turn it to vinegar. So all he found out was which one got infested first.

So someone distill some good vodka and some bad vodka and taste the left over water. Who has the tools and knowledge to do that without blowing things up.


*EDIT* better yet go with NeoPTLD's original idea and make some pure vodka that way.

Or, you could heat it up just a bit to speed up the evaporation rate so it only takes a couple hours. Just have to make sure to stop it before you evaporate all the water.

 

[NeoPTLD]

Well, I boiled down some nasty vodka in a glass pan (Corelle Vision), and most of the water. It left behind a very thick, honey like sticky crap that tastes sour.
It only took around 20 minutes, so this defies bacteria production of vinegar theory.

I'll repeat it with Smirnoff and Grey Goose later.

Perhaps someone can try boiling off the alcohol from filtered and unfiltered and taste the remaining water. The taste difference will be much much more clear.

 

[CycloWizard]

It's not so easy to separate ethanol and water at the 40% concentration found in vodka using distillation. They form an azeotropic mixture, though I can't recall its exact behavior at that concentration. To get good separation, you'd need some pretty nice equipment. If I had a multi-stage distillation column lying around my basement, I'd get on it this weekend. Maybe I can rent some time on my department's three-story column over the summer and crank out some high-quality spirits.

 

[BladeVenom]

I don't think he needs to get rid of all the alcohol. I think he's just trying to get the alcohol content down so it's easier to compare tastes without the strong taste of alcohol.

If it tastes sour get some pH test strips and see if there's a measurable difference there. If you want to do some kitchen chemistry you could use red cabbage juice.

A real rough method is mix some baking soda in and see if it fizzes, and compare them that way. You could also try neutralizing the acid with baking soda to see if it improves the flavor any. You might like it better if it's not as acidic.