What Do Winemakers Use in Their Airlocks?

Anyone who has made wine for a while knows the correct level of liquid in the airlock is vital to assuring good wine. But questions come up about what exactly one should put in the airlock to protect the wine from air and other contaminants. Some suggest just plain water, others say a sanitizing solution of water and potassium metabisulfite, while yet more suggest vodka or some other alcohol-based liquid.

What should you use? Let’s look at the three different recommendations:

Water

Traditionally, plain water has been used in airlocks for winemaking. It does a fine job of allowing carbon dioxide out of the carboy while not allowing air to get in. Some winemakers fear that perhaps water does not offer the best protection because bacteria can live in it. So they have suggested the use of sanitizing solution.

Sanitizing Solution

Many winemakers will mix up a gallon of sanitizing solution using 3 tablespoons of potassium metabisulfite per gallon of water. This will do a very good job at sanitizing equipment and home winery work areas. Sulfites inhibit bacteria growth. Because of this, some winemakers will use this solution in their airlocks.

If you are hoping to get the extra protection of bacteria control that sulfite offers, you will need to replace the solution in the airlock every week or so. Why? Because the sulfite in the water oxidizes quickly and the sulfer gas will leave the water. After about a week, the solution won’t have that much more strength over water alone.

Vodka Or Other Alcohol Based Liquid

Some winemakers recommend the use of a liquid with a high percent of alcohol in it. Alcohol of course has anti-bacterial qualities itself. Using alcohol might be fine during cooler months, but when it warms up, it should be completely avoided. And probably not for reasons you might think! It still might be offering protection to your wine, but the alcohol odor will attract fruit flies. And the last thing you want in your home winery is an infestation of fruit flies. They carry the dreaded acetobacter – acetic acid bacteria that turns wine into vinegar.

Whatever you decide to use in your airlocks, the most important thing is to remember to check them every couple of weeks. Whether you have used plain water, sulfite solution, or alcohol, it will have evaporated to some degree, and it’s vital that you keep the liquid right up to the line on the center of the airlock.