A distilling question we often her is "Why is my distillate cloudy?” As all commercial distillers know, fuel alcohol and spirits that are made correctly should be crystal clear. Fortunately, there are many ways to avoid cloudiness or "haze." Read on for several solutions that fuel alcohol and commercial distillers typically implement to avoid haze.

But before we move on, a reminder: distilling alcohol is illegal without a federal fuel alcohol or distilled spirit plant permit as well as relevant state permits. Our distillation equipment is designed for legal uses only and the information in this article is for educational purposes only. Please read our complete legal summary for more information on the legalities of distillation.

Additionally, a disclaimer. The information gathered here was gathered online is for educational purposes only. It is not intended to be relied upon by any person or entity to make any act or decision whatsoever.

Solution No. 1 - Prevent "Puking"

Over the years we've come to realize that about 99% of the time, distillate cloudiness is caused by a still "puking" into the collection vessel. When this happens, liquid in the boiler foams up into the column and then drips down through the condenser and drip arm. This is akin to a pot of water lightly boiling over on a stove. If a distillers finds themselves in the middle of a run and notices that the liquid in the collection vessel is cloudy, it means their still probably just puked! The good news is that this problem is very easy to fix. It can be fixed by lowering the temperature of the still.

Manage Temperature Carefully

Just the right amount of heat needs to be added to a still for it to function properly. If too much heat is added, liquid will boil up into the column and puke into the collection vessel, causing distillate to turn cloudy. If too little heat is added, the distillation process will take much longer than it should.

To determine how much heat to add, a distiller typically monitors still output to get a sense for what level of output corresponds with cloudy distillate. They log the temperature input details and always remain below this level. Note, the total volume of liquid added to a still will have an impact. A still that is overfilled will be more likely to puke.

Solution No. 2 - Eliminate Fusel Oils

Another potential source of cloudiness is oil. Fusel oils, produced at the end of the distillation process may lend to cloudiness in the distillate. Oils from plant material (when distilling essential oils) can cause cloudiness as well. Interestingly, at low concentrations of oil may present as crystal clear initially, but after being chilled, the liquid will develop a cloudy haze. This is called a "chill haze."

In the case of essential oils, some level of cloudiness is often unavoidable. In the case of distilled spirits and alcohol, to avoid "contamination" the master distiller will cut off the still and end the process sooner to prevent fusel oils from making their way into the collection vessel.

Solution No. 3 - Use Good Water To Lower Proof

Occasionally, alcohol will be clear until it is "proofed down." Proofing down is a process that distillers use to reduce the ABV of a solution to meet product and legal requirements. If clear spirits are "proofed down" to 80 proof (40%abv) and then become cloudy, it's most likely an issue of high fusel oil content. However, certain types of tap water can contribute to this problem as well. It doesn't happen often, but if the tap water has a high mineral content it can make cloudiness more likely.

Use Filtered Water

Most commercial distillers already know that using reverse osmosis water to proof down spirits is preferred, but perhaps some do not. Reverse osmosis water is highly filtered and almost devoid of nutrients. It is also very "neutral" tasting. Because of this distillers use it to proof because it won't alter the flavor profile of their product and because it also eliminates the chances of a haze forming. Additionally, most commercial distillers use RO water that is the same temperature as the distillate that they are poofing, which also helps to eliminate the possibility of a chill haze forming. when mixed and the water must always be poured into the distillate.