Does Filtering Improve Vodka?

I’m not a lush – really!  Yes, I am obsessed by limoncello, thoroughly enjoyed the watermelon cocktail I wrote about last week, and bought huge amounts of vodka to make homemade vanilla extract.  The only reason I am blogging about alcohol again is that my limoncello and vanilla extract adventures brought up a question I just had to test: does filtering improve vodka?  

I researched online and found two tests, neither of which satisfied my curiosity.  The first test was on an episode of the Discovery Channel show Mythbusters (#50 in 2006.) In that one, three “experts” blind taste tested expensive or “top shelf” vodka compared to cheap or “bottom shelf” vodka. The Mythbusters filtered the tested vodka between 1 and 6 times with a Brita filter.  (Although I couldn’t find it on the official Mythbusters website, I watched the episode on YouTube.)  Two of the three testers found that the filtering process did make the cheap vodka taste more like the expensive stuff, but they could still differentiate the expensive stuff, even compared to the 6x filtered cheap stuff.  

The second (and only other) test I found was by a team of reporters from Florida. They compared a truly rotgut vodka – unfiltered and then filtered 1 – 4 times – against a supposedly good brand.  They found that filtering did help, but not enough to make them want to drink the filtered (cheap) vodka.

My interest was different.  I wasn’t looking to compare different brands of vodka.  I wanted to see if I could make mid-priced, store-brand vodka smoother by filtering it. 

For purposes of using vodka in vanilla extract (as well as in limoncello and other food or drinks), I want the taste of the lemons, vanilla or other flavor to shine through.  If vodka is tasteless and odorless, I reasoned that minimizing the vodka “burn” would be the way to make the alcohol even less noticeable. 

I used a charcoal-activated Brita filter and filtered one batch of my vodka six times.  Before using the new Brita filter, I even used vodka instead of water (for soaking) to activate the charcoal, so I wouldn’t water down the vodka as it passed through the filter.

I gave a blind taste test to 7 people: 6 friends and my husband.  Each person tasted samples of the unfiltered vodka and the same vodka filtered 6 times through the Brita from flasks labeled only #1 and #2.  I asked the tasters 2 questions: 1) which vodka was smoother and 2) which vodka did they prefer?

The Results of the Test – Does Filtering Improve Vodka?

Six of the 7 said the unfiltered vodka was smoother than the filtered one.  In other words, they found that filtering did not improve vodka. When I asked which one they preferred, all 7 said the unfiltered vodka.  Tester #7 is a notable outlier – he thought the filtered was smoother but preferred the unfiltered.  He is a dear friend and a sensible guy who never lets others, or their opinions, sway him.  I can’t explain his votes and will leave it at that.

Do those results surprise you?  They surprised me. 

So while it wasn’t a blind test, I tried the unfiltered and filtered vodkas myself and came to the same conclusion. No contest – the unfiltered was smoother and I preferred it to the vodka filtered 6 times through the Brita.  Why did the unfiltered vodka taste smoother?  I have no idea.  Can anybody enlighten me?  Try it yourself and let me know what you think. Does filtering improve vodka for you?

I’m tempted to go out and buy a huge array of vodkas and test them all, against each other, and then test each one filtered against unfiltered.  Although the permutations may not be endless, I could go on way past my budget and your patience.  

But for now, I’ll mix the unfiltered and filtered vodka I already have, and finish making my bottles of vanilla extract.