What Is Louching? (How To Fix Cloudy Distillate)

Most distillers will tell you that nothing screams satisfaction like a flavorful drink. But these aroma-filled oils can take a different turn and give you a cloudy distillate – an effect that arises from louching. Although this is a fascinating phenomenon to look at, not every distiller is fond of haze in their drinks.

Louching often happens when essential oils are abundant in your distillate, and come out of solution when diluted with water. But, there are other contributing factors to a cloudy drink – like temperature and water – which will be addressed in this post.

So, if you want to know what louching is, why it happens and how to fix it, carry on reading this post. 

What Is Louching?

Louching, also known as the louche or ouzo effect, is when alcohol turns cloudy when water gets added to it. Louching happens because of the high presence of essential oils in the spirit. When you dilute the spirit, the saturation point of the solvent (ethanol) is decreased and the oils are released from suspension and separated from the water.

Louche is a French word meaning cloudy, troubled, and turbulent.

What Causes Louching?

Having an abundance of essential oils is often the cause of louching. But the interaction of the oils when diluted and the temperature of your environment and water also contribute to the ouzo effect. Below is a detailed explanation of each of these aspects.

Dilution

Alcohol is a solvent and keeps all the oils in a distillate in solution. But, as soon as you add water to dilute your alcohol, the essential oils separate from the water. The separation is indicated by the cloudy and hazy color you see in the spirit. The more water you add, the cloudier the alcohol gets as more oils come out of suspension.

Temperature

The temperature around your distilling facility and of the storage jars does determine whether your alcohol louches or not.  When the jars used to store your distillate are cold or you proof your alcohol with ice-cold water, this affects the solubility of the oils and creates a hazy appearance. This could happen even after you’ve diluted and added neutral spirit to clear it up if the temperature around is chilly. So, if you’ve added ethanol to clear the alcohol, it’s best to let the bottles sit for a day and notice if you see any changes the following day. 

Water

Tap water is notorious for having a lot of minerals added to it, which leaves you with extremely hard water. These dissolved solids are more likely to cause haze. Using filtered or demineralized water minimizes the chances of haze forming.

How Can Louching Be Prevented?

Louching is not a bad thing, it means your spirit is bursting with flavor. But if you’re planning on gifting a bottle to family and friends, you might not want to explain the science behind your hazy liquor. In this case, you can prevent louche from happening. Here are a few tips on how you can do just that.

  • When making spirits like gin where the botanicals are loaded with oil – like juniper berries, you can try distilling your spirit by vapor infusion instead of direct maceration. Vapor infusion relies on the ethanol vapors extracting the flavors as they pass through the still pipes. The downside to this is that you can end up with less flavor and aroma because it does not extract as many flavors as when the botanicals are dissolved in alcohol. 
  • Reduce the number of your botanicals if you decide to macerate them. This reduces the number of oils extracted in the solution, so you’re not left with too many oils in your distillate.
  • Make a heads cut and discard it because that’s where a high concentration of the oils lies. If you’ve got plenty of time (and spirit) at hand, you can add water to every 100 ml of spirit you collect. And if it doesn’t louche, you can start collecting your hearts. 

How Can Louching Be Reversed?

Reversing louching is beneficial if you’ve already done a spirit run and want a clear liquor, or if you want to load your spirit run with a lot of flavors. To reverse the louche effect, you’ll need a bottle of neutral spirit (ethanol). It’s flavorless and odorless, so you don’t have to worry about it affecting the flavor of your final product. 

In the container containing the proofed down spirit, add a few drops of neutral spirit one drop at a time until the alcohol clears. Adding a neutral spirit allows the oils to redissolve into the alcohol.

What Alcohol Commonly Turns White With Water?

Alcohol laden with oil often turns white when water gets added and this typically happens with anise-flavored spirits. A few of those readily available on the market include the following:

  • Absinthe
  • Pastis
  • Pernod
  • Ouzo
  • Raki
  • Limoncello

Is Cloudy Alcohol Safe To Drink?

Cloudy spirit is absolutely safe to drink. The great news is that a hazy spirit means your spirit has heaps of flavor because of the presence of essential oils. 

Conclusion

Louching is simply proof that you’ve attained a very aromatic spirit. But the thought – and sight – of a cloudy drink is not everyone’s glass of spirit. Luckily, there are ways of preventing and reversing the highly active oils in your spirit to give you the much-loved spirit.

Techniques such as adding neutral spirit to your cloudy drink or reducing the volume of oil-rich botanicals when distilling serve beneficial in providing you with a clear drink. Try one of the methods mentioned above when experimenting with your spirit, then you’ll most likely achieve your desired results on brew day.

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