The Distillation of Gin

12th September 2018

Science

Gin starts its life as almost entirely pure ethanol. In order to transform into one of the world’s favourite spirit, it must first undergo a process of distillation.

This alcoholic beverage undergoes the same process that some of our purified water products undergo: distillation. Gin is produced by redistilling ethanol and infusing it with botanical flavourings, like juniper berries or lemon peel.

The distilling set-up is remarkably similar to the one used in water treatment plants, and the science is exactly the same.

Close up of juniper berries, which are used to flavour gin

Juniper berries are the most common botanical used to flavour gin. Its aromatic compounds are infused into the drink via a process of distillation – but on their own, juniper berries are actually very bitter.

What is Distillation?

Distillation is a purification method that is commonly used to create distilled water. Unlike other purification techniques, like deionisation or demineralisation, distillation is not a chemical reaction but a separation process in which the components of a liquid you do not want are removed from the parts you want to keep.

The process involves heating a liquid until it begins to vaporise. The vapour is then collected and condensed back into a high-purity liquid. Meanwhile, the parts of the liquid you wanted to remove, like impurities, do not vaporise and are left behind.

There are many variations to this process, and each of them is used across a range of applications:

  • Steam distillation is used in the perfume industry
  • Vacuum distillation is preferred in pharmaceutical manufacturing
  • Fractional distillation is often used in oil refineries
  • Double distillation is used to gain a higher purity product

At ReAgent, we use distillation to manufacture high-quality distilled water for use in pharmaceuticals, laboratories, automotive systems and even electricals. But this popular technique is also used by drinks manufacturers to create the perfect flavoured gin.

3 Methods of Gin Distillation

Every drinks company has its own preferred method for distilling gin, and each of these creates an array of different flavours and intensities.

At its roots, the distillation process that gin undergoes is virtually identical to the one ReAgent carries out in its factory. But while the science may be the same, the variations in timing, temperatures and flavourings lead to a very different – and tasty – end result.

A square blue glass bottle of gin against a red wall

Gin can either undergo steam distillation or vacuum distillation. There are also many different methods used to infuse it with botanical flavourings.

  1. Steeping of Botanicals

Steeping is a process that is used to extract flavour from certain foods by soaking and thereby macerating it in a liquid. In the gin industry, aromatic botanicals are put through this process before distillation so that the base spirit, i.e. almost pure ethanol, is already infused with flavours.

Botanicals like juniper berries, which are commonly used in gin, are steeped in ethanol and left to soak for up to 48 hours. When the liquid is then distilled, the essential oils and aromatic compounds extracted from the botanicals are carried by the vapour that condenses at the top.

When the vapour is condensed back into a liquid, it is infused with the characteristic flavours of gin that we all know and love. This is one of the most traditional methods of gin distillation and is widely used by the makers of Beefeater Gin.

  1. Vapour Infusion

This method of distillation involves placing the botanicals above the base spirit whilst it is being heated. In this process, it is the vapour that is getting infused with the aromatic compounds rather than the liquid itself.

As the ethanol begins to vaporise, it passes through the botanicals and becomes infused with their essential oils and flavours. These will stay locked into the vapour as it is condensed and transformed into gin.

Vapour infusion is a less intense form of gin distillation because the botanicals aren’t being directly soaked and macerated in the base spirit, meaning that the final product will have a much more subtle flavour than gin whose botanicals have been steeped in ethanol.

This is shown by the fact that vapour infusion is the preferred distillation method for Bombay Sapphire Gin, which has a much gentler taste than Beefeater Gin.

  1. Vacuum Distillation

Vacuum distillation works very similarly to typical steam distillation. The only difference is that by using a vacuum, you can actually decrease the environmental pressure above the liquid mixture so that it is less than its vapour pressure. This will correspondingly lower the boiling point of the liquid.

Therefore, vacuum distillation can actually be performed without the use of heat. In industries like pharmaceutical manufacturing, this is useful because it can be more efficient.

In the gin industry, vacuum distillation is often used by companies in order to achieve a fresh tasting beverage. Because the use of a vacuum reduces the environmental pressure, the boiling point of ethanol is also reduced and, therefore, the botanicals are less exposed to it.

This results in a very fresh-tasting beverage since the botanicals have less of a presence in the final product. If this is more up your street than the fervent Beefeater, try brands like Sacred Gin or Victory Gin who tend to favour the vacuum distillation method.

A row of Bombay Sapphire bottles

While we’re not experienced gin-makers, ReAgent is an expert when it comes to distillation. Our distilled water products are internationally recognised for their purity, and they are even backed by a 100% quality guarantee.

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