An Edinburgh-based distillery has launched a range of gins that change colour when tonic is added.

The Old Curiosity, which is the latest venture from Scottish herbologist Hamish Martin and partner Steve Ross, has launched three floral gins: Apothecary Rose, Lavender & Echinacea and Chamomile & Cornflower. All three are made from botanicals that are hand-grown, dried and infused by Martin’s team at his 7.5acre business, the Secret Herb Garden.

Apothecary Rose has been created from one of the oldest rose varieties in the world; it has been used in herbal remedies and tinctures for more than 5,000 years. The flower brings an elegant flavour to the spirit, according to the producer, and it has colour changing properties that see the liquid change from pale gold to vibrant pink.

Lavender & Echinacea have restorative and medicinal properties respectively, resulting in a “soul healing” gin, which turns from purple to pink. The third variant transforms from blue to pale pink.

The gins are all 100% natural, free of chemicals, sugars and flavour compounds; these natural qualities allow the liquid to change colour as the pH of the drink varies when tonic is added, according to the producer. 

The Old Curiosity range is available from specialist off-licences, retailers and outlets in Scotland and from Harvey Nichols nationwide from 1 February, priced at £42 for a 50cl bottle.