The Science of Making Great Vodka
Vodka is the most heavily consumed spirit in the United States by far, but it doesn't get nearly as much attention as whiskey, tequila and other spirit categories. But making great vodka is actually a lot more difficult than making almost any other spirit. Think about it... the cleaner something needs to taste, the more apparent any errors will be in the final product.
Whiskeys often come out of the still as something so harsh tasting, it's known as white dog or white lightning. And that's honestly not entirely attributable to it being over 60% alcohol. Years in oak barrels smooth out the rough edges and turn it into something ranging from palatable to divine. Vodka, on the other hand, has to be something approaching pretty good right out of the still! So how do we accomplish this?
According to the recently revised TTB definition of Vodka or Neutral Spirits:
“Neutral spirits” or “alcohol” are distilled spirits distilled from any suitable material at or above 95 percent alcohol by volume (190° proof), and, if bottled, bottled at not less than 40 percent alcohol by volume (80° proof). Neutral spirits other than the type “grain spirits” may be designated as “neutral spirits” or “alcohol” on a label. Neutral spirits (other than the type “grain spirits”) may not be aged in wood barrels at any time.
Neutral spirits which may be treated with up to two grams per liter of sugar and up to one gram per liter of citric acid. Products to be labeled as vodka may not be aged or stored in wood barrels at any time except when stored in paraffin-lined wood barrels and labeled as bottled in bond pursuant to § 5.88. Vodka treated and filtered with not less than one ounce of activated carbon or activated charcoal per 100 wine gallons of spirits may be labeled as “charcoal filtered.” Addition of any other flavoring or blending materials changes the classification to flavored vodka or to a distilled spirits specialty product, as appropriate. Vodka must be designated on the label as “neutral spirits,” “alcohol,” or “vodka”.
What this means is that, to be considered vodka, the spirit must be distilled at 95% or more alcohol by volume. Consider that whiskey must be distilled below 80% alcohol by volume. The difference in energy inputs, equipment, etc. to get from 80% to 95% alcohol is significant. And most whiskey is distilled at closer to 60% alcohol in any case because a higher water percentage brings over more flavor. Therefore, distilling vodka is inherently much more expensive and energy intensive than other spirits. And even so, it must be filtered with charcoal (activated carbon) to remove additional impurities and be rendered absent of "distinctive character, aroma, taste or color." Of course, it's all but impossible to remove 100% of the original grain's character from the final vodka.
The first important step is the mash. What yeast is used, the quality of the grains, etc. If you start with a bad mash, some of that will inevitably end up in the vodka. Good in equals good out. Most craft distilleries opt to purchase industrially distilled neutral grain spirits to avoid all of the capital equipment and up-front cost and labor. But starting from this and simply adding purified water, while technically sufficient to call it vodka in the eyes of the TTB, will not lead to a great vodka. The secret is how the neutral grain spirit, or distilled spirit, is treated afterwards.
You may have seen a YouTube video or two in the past where people claim that anyone can make a bad vodka taste a lot better by running it through a Brita filter. This is actually very much true. But there's quite a bit more to it than that.
Activated carbon is a form of carbon used to filter contaminants from water, air and many types of chemistries, including alcohol (ethanol). It is processed (activated) to have microscopic, low-volume pores of varying sizes, depending on the media and activation method used, that dramatically increase the surface area available for adsorption of contaminants. The pore size and selectivity of the carbon for contaminants is dependent on a variety of factors, including the media from which the carbon is created, and the activation method used.
Carbon media is based on different types of tree woods, coconuts, bamboo, coal and many other sources. The first step is carbonization, which involves heating the carbon rich material at extreme temperatures to sort of pop it like a popcorn kernel, which generates a highly porous carbon with vastly increased surface area. Next it is activated by introducing oxygen via gas or chemical treatment means. Oxygenated gas may be pumped through the carbon at 900-1200 Celsius, causing oxygen atoms to bond to the carbon surface. Chemical activation typically occurs at the same time as carbonization. The media is immersed in a chemical bath (typically acid or base), then heated to 450-900 Celsius for a period of time, which both carbonizes and activates the media at the same time.
The takeaway here is that which activated carbon is used will have a significant impact on the final result. Any carbon will improve a bad vodka to some degree, but to make it great? Well, that requires a more scientific approach.
At Skeptic Distillery, we always strive to make tweaks and improvements to proven methods such as carbon filtration, to produce superior results. To accomplish this with our vodkas, we custom built our carbon filtration equipment, where we pump our vodka distillate through after proofing to a specific alcohol percentage. We pump it through at a specific rate through a series of two carbon beds containing a unique blend of activated carbons a minimum of four times, equaling eight or more total passes. Our process and activated carbon media for this process, not to mention cold distillation, delivers an unparalleled clean and smooth taste. After carbon filtration, purified water is added once more to bring the vodka down to 40% abv. And perhaps most important of all, NO SUGAR OR OTHER ADDITIVES!
The result of all this trial and error, experimentation and effort, is a corn-based vodka that is exceptionally smooth, clean tasting and pure, without the need to smooth it out with additives and sugar. To borrow (and tweak, as we do) a line from Uncle Ben of Spider-Man: "with great [vodka] comes great [experimentation]. So, before you sip on your next vodka martini or drink your vodka soda, take a moment to consider all the effort and energy that went into making that vodka taste the unique way that it does!
Cheers and thanks for reading!