My DP is on the bulletproof diet and is now completely obsessed with coffee.
He uses Kerrygold but as previously mentioned, most cows in the UK are grass fed so any organic, unsalted butter should be ok. We also like Rachel's.
Butter coffee is surprisingly yummy and easy to make by blending a tbsp in some brewed coffee.
I think the most important thing is where you get the coffee from. It has to be single estate and processed in a certain way. We now have bulletproof coffee shipped from the states but have bought it from Monmouth coffee before.
I told you he was obsessed!