I have been making my own cofee flavour for some time. I add instant granules of expresso cofee (2 good teaspoons) to 20ml of neat standard strength vodca in a small tubular bottle.Shake well and leave for several days shaking well when ever I remember.After a couple of days put the bottle in the fridge and leave overnight.You will find the contents have seperated into a dark but clear upper layer of cofee liquor and a lower muddy layer containing the undissolved solids.Simply dropper off the upper layer and add to your nic
juice (in my case French Pipe),the more you add the stronger the cofee flavour.