I've had a life-long fancy for using vodka to clean sanitize and naturally use it in my air-lock.

Given that it is only 40%, however, and I live in California where pure grain alcohol is illegal, would starsan be better?

I guess the two dimensions to take into account would be sanitation and cost, but I am more concerned about sanitation.


8 Answers 8


Water - it's cheap, it's always available, and does the job adequately. No need for anything else when something so simple works so well.


Foil. :)

Either vodka or star-san are perfectly fine. Water will work just as well. The liquid in an airlock does not strictly need to be sanitary, it just needs to provide a barrier for insects, primarily.

  • 2
    I started with vodka and when it ran out I switched to tap water. No problems. I use StarSan if I have some handy, otherwise it's water. Or foil over the top.
    – Denny Conn
    May 15, 2013 at 18:25
  • I use iodophor water left over from sterilizing other components of the brew process. Never had a problem. May 15, 2013 at 21:13

Personally, I use either distilled water or vodka. However, star-san is perfectly acceptable to put in an airlock, it isn't going to hurt the fermenting beer sitting below it. In fact, as I understand it, yeast actually LIKE smallish quantities of star-san and that is one of the several reasons to "not fear the foam"™ Now, there is one potential downside that I can see to using star-san in the airlock and it comes back to the foam. Unless you keep a close eye one it and be sure to keep adding more, it will wind up frothing heavily and coming up out of the top of the airlock. I did use star-san in the airlock once for the duration of the primary... and due to having to be vigilant about topping it up, I went back to distilled water or vodka.


The actual sanitation qualities, when used as air-lock liquid, between the sanitizing solution you have on brewday (StarSan + water) and vodka are pretty much the same.

My opinion - if you've had a lifelong fantasy of doing something and it's not very expensive, I'd say the benefits outweigh the costs!


Not that it matters much, but the answer is VODKA, with the caveat that neither are as superior to water as you might imagine.

StarSan concentrate works by lowering the pH of the water its added to. However, when you add StarSan to any water that isn't completely distilled, and is exposed to oxygen, then the StarSan starts breaking down, and the pH of the solution will slowly rise to "normal" levels where bacterial growth isn't inhibited. If your StarSan solution gets cloudy, then that means that its no longer sufficiently acidic to work as a sanitizer. If you put normal water + StarSan into an airlock, within a day or two it will be cloudy, and therefor only as effective as plain water.

Vodka has the advantage of being 40% ethanol, which will inhibit bacterial growth as well, but it will also slowly loose its ethanol to evaporation over time. I'm not sure how long this will take, but eventually you'll be left with nearly-pure H20.

Food-grade glycerin is the best choice if you want a liquid that won't evaporate out of the airlock after a few months of neglect.


Anything works since it creates a barrier to microbes.

But if you are a beginner, some incident can occur and the fluid can be dripped inside the fermenter (over your beer), so prefer something that cannot spoil your beer, like water (dechlorinated), alcohol (ethanol), diluted StarSan, and so on.


I've always used a strong sulphite (that's sufite in Americanese ;-) solution in fermentation locks. It's dirt cheap, and generally handy around the brewery/winery. Among other things, I use it to neutralize chlorine bleaches and detergents, or any other alkaline cleanser such as Oxi-Clean.


I use grain alcohol (everclear, clear springs) mixed with about 50% water to alcohol. Check daily, add alcohol and maybe a bit of h20 if its evaporating too quickly for your liking. That's what I'm doing now, but trying to find the best method.

  • the s style airlocks I prefer but have to upgrade to a bigger system using a big bucket with a backflow air loop. any suggestions would be nice. Sep 7, 2016 at 23:57

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