The Makings of Gin…Part 1

This traditional approach, known as the steep and boil method, represents just one among several techniques employed in gin production. Other methods include vapour infusion and vacuum distillation.

As gin’s base spirit can be made by fermenting and distilling almost any agricultural product, there are many different variations of mash types to choose from. Most gins are made using a variety of grain such as corn, rye, malted barley, or wheat. Wheat creates an incredibly clean spirit and a popular choice here with Australia having a global reputation for high-quality production of wheat.

Pure grain spirit, approx. 94% ABV, is diluted to around 30% ABV with water and is pumped into a stills pot. Dry botanicals are usually added directly into the pot with the base spirit — steeping. The key ingredient to gin is juniper — it must contain juniper. As you can imaging, the scope of botanicals used for flavouring is endless — coriander (seed) being the second most used, but also used are citrus peel, spices, roots, fruits, flowers…all in varying combinations and concentrations.

Vapour infusion involves heating the spirit in a still, known as a Carter-head still. This features a botanicals basket above. As the spirit in the pot is boiling, vapours begin to rise out of the top of the pot, pass through the botanical basket, steaming the botanicals and infusing their flavours into the vapour.

For the next several hours the liquid will condense and re-condense as it passes from the pot, through the basket and then the separate plates on the column of the still. Each of these plates remains closed, creating mini distillation of its own, further refining and purifying the spirit.

The distillate has returned to a high ABV spirit, but now with the flavours and aromas of the botanicals. The high ABV gin can now be diluted back to a normal range (30-50%) and then is ready for bottling.

Further infusion of flavours may occur by adding more botanicals, such as native grasses, herbs and sometimes pine needles) to a stainless-steel tank and then the finished gin is added. This post distillation mashing of gin will take on colour from these added botanicals infused.

Left chilled for long periods gin can go cloudy. The botanical oils condense and separate from the liquid in cold temperatures. Commercial distilleries will chill filter the product before bottling to ensure this does not happen, but this filtering can also take some of the flavour. Most Australian craft distilleries follow the traditional method and do not chill filter their products.

PMG stills are custom build to enable craft distillers to choose the exact configuration they want to create award winning gins. Our sales and engineering team can advise on exactly what design of still will help you to distil a delicious and unique gin.