I'm enjoying this mix;
1 drop per 10mL Kona Coffee TFA (try this at third or half strength if you aren't a coffee nut)
10% Blueberry (Extra) Flavor TFA
5% Blueberry (Wild) Flavor TFA
One could go a bit lighter on the coffee in an attempt to bring the blueberry forward but I'm not sure. In no way shape or form increase the kona flavor, this is upper limit without a doubt. I purchased one ounce and its going into deep freeze to prolong its life. Huge bang for your buck on this for sure.
As for the kona coffee, your going to love it or hate it. I love it. I do believe this would go well with tobacco flavors at third to half strength, maybe as low as quarter strength.
A more blueberry on par with coffee recipe;
16% of the above to 84% of the following works well.
10% Blueberry (Extra) Flavor TFA
5% Blueberry (Wild) Flavor TFA
If your looking to make a blend of coffee and blueberry flavors, this would be your ticket, its still going to be coffee forward yet very light, but there will be a clear blueberry finish.
Blueberry (Wild) and Kona Coffee are alcohol based so this may do well with an open steep for a day to rid the liquid of some of the alcohol. Otherwise it's good to go in short order. A deep steep isn't required with these ingredients.
Kona Coffee when mixed with Bavarian Cream at 10%, needs a deep, forget you made it, steep of at least 5 weeks in my honest opinion for it to really start to shine brilliantly.
Maurice