how gin is made

The secrets of the stills: how gin is made

A few years ago, I was having dinner with some friends in London. One of them had been pontificating about wine. It was getting to the point at which he was describing how different soils in neighbouring fields can produce radically different grapes and wines with completely unique flavours. That was when I brought up gin and its infinite variety. I started the conversation making the point that gin was essentially a flavoured vodka. But he was adamant that I was wrong.
“Gin is gin”, he said. “Completely different!”
For the sake of the evening, I didn’t challenge him but it got me thinking. While we all love drinking it, most of us don’t know how gin is made. So, this is for all of us gin lovers who have managed to master the art of drinking the stuff but haven’t yet mastered the art of distilling it.

What is gin?

There are three basic rules that gin has to follow to be classified as gin:

  1. Gin must be based on a neutral spirit (unflavoured vodka, ethanol etc).
  2. It must also be bottled at a minimum alcoholic strength of 37.5% ABV.
  3. Finally, it must contain juniper as its dominant flavour.

The rest is up to you. Some prefer London Dry gins, others prefer Genever gin or Old Tom. Some prefer fruity gins or glorious floral infusions. Others prefer citrus or earthy tones. And there’s now a huge industry churning our what we call “flavoured gins” (some good, some not so good!).

Complex flavours, infinite variety

But the real beauty of a good gin is its complexity and its infinite variety. There is a subtlety to a good gin that is almost an art form on a par with Scotch whiskey.
This complex, sophisticated mix is achieved through the expertise of each individual distiller working diligently to achieve the exact flavour profile that they prefer. For many of us, we either picture big brand distilleries such as Bombay Sapphire pumping out industrial quantities of gin (think the big brands here!) Or, you could be imagining something more niche – a bit more like Breaking Bad, with people in white coats staring at bubbling potions to create their own small batch gin delights. The truth is it’s both of those (and everything in between).

Back to basics

So, let’s start at the beginning.
Gin is one of a group of spirits that include Akvavit and a number of anise-flavoured products that get their character directly from the supplemental flavours added during the distilling process instead of the raw material they are made from.
Essentially gin is simply a neutral spirit to which juniper and other flavours have been added. The base spirit can be fermented from a wide rage of things from grain to milk (and plenty in between). The resulting clear, neutral alcohol gives the distiller a blank canvas on which to create a masterpiece.

Maceration, distillation and infusion

Flavours can then be added through any one of three recognised methods:

  1. Maceration: Firstly, through a process of simple maceration which extracts both flavour and colour from the ingredients to give its own unique profile. For a clear colour, the maceration liquid still needs to be distilled.
  2. Distillation: The second approach is known as “re-distillation”. Once the product has gone through an initial distillation to create its neutral spirit, it is then “re-distilled”. During this process, the vapours that boil off carry selected flavour-frequencies on into the final product, while leaving the colour behind.
    The result is an aromatic mix of complex compounds within a clear liquid, with a distinct concentrated smell.
  3. Infusion: The third approach is to add “off the shelf” compounded flavours to a neutral spirit, mixing it up in the same way as you would mix your own bespoke cocktail. This is the easiest method and the result is the sort of cheap gin that you find on the bottom shelves of supermarket.

So when does the magic start?

Well the first stage is fermentation. This is where the alcohol is created before it is distilled into gin. Alcohol can be created from a huge range of foodstuffs including grain, grapes, potatoes and even milk. Grain is the most common source and it is often ground down to help it to release starch, which then converts into sugar. These sugars are then mixed with water to make a mash before being transferred to the mash “tun”. This is where the fermentation fun starts.

Fermenting fun

Fermentation is simply the natural process of decomposition. But you’ll need to add some yeast for the real fun to begin. The yeast feeds on the sugar and produces alcohol and carbon dioxide. This can take anywhere from a few hours to a few weeks depending on the process used. The resulting liquid is a low alcohol brew, commonly known as the “mash”. It’s not dissimilar to beer.
But how does this beer-like liquid become distilled alcohol?

The distillation process

And now we can reveal the secrets of the stills.
The fermented wash is heated to boiling point in a “still”. During this process, the “wash” evaporates before condensing at lower temperatures. These vapors are then captured by the distillers and separated to create a new mixture.
After several distillations, the resulting spirit is generally filtered through charcoal or carbon to remove any remaining sediment and impurities. The resulting clean, pure, alcoholic spirit is now ready for bottling, flavouring, aging or drinking.

Adding the ingredients

As we know, gin is essentially vodka that has been distilled with added botanicals. But, while Juniper berries have to dominate the flavour for your spirit to qualify as gin, other common botanicals are generally added at this stage including cumin, wormwood and coriander. More unusual ones include cassia root and frankincense.
With the rise of craft gin, ingredients are becoming increasingly exotic with the rise and rise of flavoured spirits. The final blend is only limited by the distillers imagination.

The stills: tradition vs efficiency

But to make all this come together, you need a still.
If you’re interested in trying this out at home, you can actually purchase individual desktop stills from Amazon for under 100 euros.
However, for the professionals, there are only two main types – pot stills and column stills.

Pot stills: smaller and more traditional. They’re generally made from copper and they can be quite labour intensive requiring regular cleaning . But actually, the process is quite simple. Heat the mix up in the boiler and watch it vapourise and separate. This happens because alcohol and water boil at different temperatures.
This results in the alcohol vapours condensing to leave behind a strong alcoholic liquid. Generally, this liquid is then redistilled again for a smoother taste.

Column stills: more efficient but more industrial and less historical.
Multiple chambers allow the producers to enable fractional distillation – or separate distillations within the still.
This gives distillers more flexibility and precision and they produce higher alcohol spirits. Some producers also pass steam directly through the ingredients to distil alcohol or to extract essential oils from the plants or botanicals.
The final mixture is then mixed with water before bottling to reduce it to the final desired strength. Definitely more efficient (but less character).

Know what you’re drinking!

So, there you go – a brief guide to distillation.
If you’re inspired to have a go yourself, then pick up a still and have fun experimenting with your own flavours. Otherwise, just carry on drinking the gin, smug in the knowledge that you actually know (and appreciate) exactly how this beautiful, complex and subtle drink is made.

Written by Steve (with a little help from Ruddles, the gin dog!)

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