The Old Curiosity gin range. Credit: The Old Curiosity distillery.

Edinburgh-based The Old Curiosity Distillery has launched a range of three gins that change colour when mixed with tonic water.

The three flavours are apothecary rose, lavender and echinacea, and chamomile and cornflower. Apothecary rose changes from gold to a bright pink, lavender and echinacea transforms from purple to a lilac pink and chamomile and cornflower turns a very pale pink from bright blue.

The Old Curiosity Distillery first discovered the colour-changing phenomenon when it was developing its the apothecary rose offering. The reason these herbal gins change colour when tonic is added to them is because the tonic affects the pH of the liquid and the reaction of the botanical elements to the pH change involves a colour transformation.

Hamish Martin and Steve Ross co-founded The Old Curiosity Distillery in 2017. Herbologist Hamish Martin with experience in the wine industry founded a secret herb garden on an abandoned site on the outskirts of Edinburgh in 2012 to grow herbs to include in whole range of products. In 2016, mixologist Steve Ross volunteered at the garden and began discussing the possibility of collaborating with Martin on their own alcohol products.

The products are naturally distilled and are free from any chemicals, added sugar, fruit extracts and flavour compounds allowing the gins’ unique botanical flavours to come to the forefront. All the flowers and herbs used in its products are hand-grown, dried and infused on site.

The UK has seen a large growth in the number of small, independent gin distilleries creating speciality, craft products–14 new distilleries opened in 2016, more than double the number in 2010. Sales of gin superseded £1bn in 2016 for the first time, according to the Wine and Spirit Trade Association.

Craft gin’s advancement has been facilitated by consumers’ desire for more choice, bolder flavours and chemical-free authentic products. This has been fuelled by educational tours of distilleries and specialist gin bars with an extensive range of tonics.

Currently, The Old Curiosity Distillery’s gins are available on the company’s and in selected stores across Scotland. It is also launching in more retailers in the next couple of months; notably nationwide at Harvey Nichols on 1 February 2018.