For those new to distilling here is a rundown on the basic process and the additional processes that set Gin apart from other spirits.
First things first you start with a volume of some form of grain, molasses, potato, or other sugar containing material. This is soaked/heated to extract the sugars then a yeast is introduced to the resulting mash the yeast turns the sugars into alcohol and voila! a little filtering and you have a liquid that is ready for distilling.
This resultant liquid is relatively low in alcohol so now it is time for distillation. The liquid is heated up to around 80 degrees C where the ethanol begins to evaporate and rise up the still. Now you will note that at 80 degrees C this temperature is not high enough to evaporate water so you are effectively extracting the ethanol out of the mix leaving the water behind in the still. As the steam rises upwards in the still it reaches a point where there is a condenser this condenser is essentially a part of the still that is being cooled. So your vapour that is mostly ethanol is cooled back below the 80 degree C mark and becomes a liquid again. This liquid runs down a separate tube and is collected ready for phase 2. Gin still has another round of distilling to go. Where your vodka is ready to bottle and your whiskey is ready to go into casks Gin still has another round of distillation to instill its unique taste.
Why is Gin Unique
There are 2 main methods that distilleries use to give their Gin its unique taste.
1) Steeping: your botanicals including Juniper are steeped or soaked in your previously created ethanol for a period of time which differs dependent on distillery and could be anywhere from minutes to weeks but commonly around the 1-2 day range. Once this steeping is completed the spent botanicals are removed from your ethanol mix. The ethanol mix is added into your still and as above this is redistilled at a slightly higher temperature to your original distillation, resulting in a now juniper/botanically charged distillation which is ready to use in your final product.
2) Vapour infusion: takes your Juniper and other Botanicals and suspends them above the previously distilled pure ethanol. When distillation takes place the ethanol vapours rise and are forced to travel through the botanicals suspended above it. The resulting distillation is now infused with Juniper and your other botanicals.
Note: some distilleries combine both distillation of base sugar/yeast mix and a vapour infusion method using a method called "One shot distillation".
Both produce quite different results for different botanicals. Steeping is the more commonly used method. As an example steeping juniper produces a much more dominant Pine heavy juniper flavour where vapour infusion tends to even the flavours out a little more allowing other botanicals to have a stronger representation in the end taste.
So why craft?
A craft distiller takes pride in producing their products often using costly and inefficient methods designed solely to produce the best flavour possible. You wouldn’t see a large commercial distillery hand crushing there botanicals to ensure the right amount of oils are exposed for their distillation. Or using 2 different steeping processes followed by an infusion process to pack as much flavour into the distillation as physically possible.
Craft Gin/Spirits are often produced in small 50-500 Litre stills, these stills are often designed and built by the distiller. A craft distiller is constantly involved in the process tweaking and improving as time goes on. Batches can be as small as 40 bottles or less, where a big manufacturer could be producing in automated stills with over 100,000 litre capacity.
But for me most importantly, craft distilleries have the flexibility to be constantly experimenting to with new flavours/botanicals and methods.