Add vodka or high proof grain spirit and it will keep for a year

Swapped the vermouth to Dolin Blanc and added 5 ml of simple and it lifts the drink.

I played with this and used Havana Club Añejo 3 Años which had been infused with Kaffir Lime, Lemongrass, Ginger and Chilli under vacuum for 10 days. Combined with the basil you get that real sweet, sour, salty, bitter aromatic whack with some residual heat. I garnished with a piece of pineapple and a ring of sliced red chilli. It's like South East Asia in a glass.