A version of this article originally appeared on VICE Italy.
Over the past few months, people have been sharing videos on TikTok where they pour cheap vodka through a filter jug. After tasting it, they look amazed. They say the vodka tastes a hell of a lot better - so much so, the trend has now garnered over 90 million views.
Real or not, the hack is nothing new. In 2006, it featured in an episode of MythBusters. They, too, seemed to think that filtering vodka improved its taste, though a scientist ultimately debunked it on the grounds that there was no chemical difference between the filtered and unfiltered versions.
Strap in for the science: Vodka is a spirit, generally made from grains or potatoes, that goes through fermentation, distillation, dilution and filtration. Ethanol - or pure alcohol - is formed during fermentation. The thing is, fermentation also results in other byproducts called congeners. These are acids and other types of alcohol like isobutylene, aldehydes, esters and ketones, which give spirits, such as rum and whisky, their flavour.
But good vodka is supposed to be pure, taste like nothing and go down the hatchet as smooth as water. (In fact, the word vodka comes from “voda”, which means water in Russian.)
After fermentation, the solution still doesn’t have enough alcohol, so it’s distilled – basically boiled – to reduce congeners and increase ethanol. That’s because ethanol boils at 78 °C, while some congeners evaporate at lower temperatures.
These processes are repeated many times to get premium vodkas, but for cheaper ones, manufacturers do the bare minimum.
Sure, I like premium vodka, but I have far more important things to spend my money on. So, I decided to take on the experiment too – or rather, get six of my coworkers to do it. I got myself a filter jug and a €13 bottle of vodka. At 3PM (it’s six o’clock somewhere), I began to filter it.
I’ve got to say, spending an afternoon pouring shots for my colleagues in the name of investigative journalism really is what I’d always hoped to do as a grown-up.
Next, I split the tasting into three samples: unfiltered vodka, vodka filtered once and vodka filtered six times. That’s the magic number for the best result, according to MythBusters. The hosts of the show switched filters in between each step. That seemed like a waste to me, so I used the same filter throughout the process. (Water filters are only supposed to be switched every couple of months.)
My test subjects tasted the vodka separately to avoid influencing each other’s responses. They had no idea which sample was which and I also switched the tasting order, just in case.
The result was pretty surprising. Just looking at the samples, the vodka filtered once looked clearer. When tasting it, all six colleagues noticed a difference. Three of them strongly preferred the vodka filtered once, and the other three preferred the sample filtered six times. None of them thought the unfiltered vodka tasted the best.
The impact of filtering multiple times, however, wasn’t clear. Two people thought the sample filtered six times tasted vile - even worse than unfiltered vodka. And although unfiltered vodka wasn’t anyone’s top choice, it ranked second for four out of six drinkers.
It turns out that a 2015 study comparing 12 vodka brands found multiple distillations and filtrations don’t seem to benefit the quality at all. The study says that, more than anything, it’s the fermentation process and quality of the basic ingredients that are the key factors to reaching lower impurity levels. Plus, filtering doesn’t change the liquor’s alcohol content and does not prevent hangovers, contrary to what some TikTok videos claim.
My conclusion to all of this is: if you add up the cost of cheap vodka to the price of the filters, it comes out as more expensive than a bottle of premium vodka (ranging between €35 to €50). So, don’t bother - unless you were going to invest in filters anyway.
That being said, drinking filtered water with an aftertaste of vodka at the office might brighten up your day.