Frothing Your Whiskey: Science Or Quack Gimmick?

By Richard Thomas

The other day my inbox had a share in it, a video short from the TikToker Barchemistry about frothing whiskey to improve its taste. The idea is to use a milk frother, the sort of device that an avid home barista ought to have handy, to give the liquid a vigorous stir and expose more of its total volume to the air.

Based on Barchemistry’s video, the idea did not originate with him, and I have no idea who hit upon it. But it is gaining a degree of trendiness if Food Republic and Tasting Table are doing articles about it, to say nothing of TikTokers. Bourbon bro podcasters and YouTubers have also gotten in on the act. So, what is the deal with frothing?

One does not need to be a chemist or even a sensory scientist to answer that question, just somebody who remembers their high school or college chemistry class while also being familiar with whiskey-drinking practices. Frothing is the same thing as aerating, the point of which is oxidation. This is what a whiskey drinker does when they leave their glass out and undisturbed for a spell to “breathe.” Wine drinkers often do the same thing, either with their glass or their entire bottle by transfer to a wine decanter. The difference is that the oxidation takes place only in that part of the liquid in contact with the air, which in a tumbler isn’t much and in a Glencairn glass is even less. Frothing exposes exponentially more of the liquid to the air, even going so far as to temporarily trap pockets of air into the liquid (the froth), greatly accelerating the process of oxidation.

This is what the better comments on frothing should mention, but the one thing none I’ve read or heard yet mentions is that frothing also excites the liquid in a chemical sense. When you stir something up and set it in motion, you add energy, which also adds heat. I’ve tracts I’ve read about agitating other liquids, frothing can add a substantial fraction of a degree Fahrenheit to the temperature. Keeping in mind that alcohol has a much lower boiling point than water, so one would never want to heat it up on a stove top or in a microwave, that side effect of frothing is also worth keeping in mind.

However, whether aerating or warming whiskeys is desirable or not falls into the same category as adding water. While I can prove frothing accelerates oxidation and slightly warms the liquid, just as chemists can prove adding water unlocks reactions and changes the taste in whiskey, what I cannot prove is that these processes are objectively good things for drinkers. Taste is, after all, ultimately subjective. You may or may not prefer watering or airing of your whiskey, or even of a particular pour.

That latter would be especially encouraging, by my way of thinking, because it means the person in question is paying enough attention to pose the question of “does this improve with airing?” instead of just doing the airing by rote because someone recommended it.

So maybe there is some merit to frothing, but I think that depends on the tastes of the drinker in question. Certainly if you prefer your whiskey to breathe a spell before and are willing to invest $20 on a new gizmo, then frothing is something you should try. If you do not regularly breathe your whiskey, I cannot imagine why you should jump straight to frothing, because there is one last thing to keep in mind.

Some of the bros raving about frothing also have a track record of raving about hazmat whiskey. The apostles of drinking rocket fuel-grade American whiskeys almost invariably express hostility to the idea of adding water, scoffing at the proven science of the matter (and note all the science proves is more water means more of a certain set of reactions, not that it objectively tastes better) to justify their love of sipping on stuff that could power a car. My own guess is that anyone who advocates for both frothing and hazmats is not especially concerned with what really works and what doesn’t, but just loves gimmicky nerdom and clicks on their social media account.