I tried putting powedered kava kava root in my coffee machine – with disastrous results. Wet kava kava root is very dense, almost like wet clay. It clogs up the coffee filter, and the machine overflows.
But I have an espresso machine, and I figured that the pressure and steam would force the water through the kava root powder. Disastrous results again – the kava was still too dense, and the seals on my espresso machine failed, resulting in jets of superheated steam shooting out at unexpected places and scalding off my eyebrows.
So my next experiment was to blend powdered kava kava root with coffee grounds. This actually works pretty well and produces a nice cup of coffee with a tinge of kava taste and sensation. One must still be very cautious to not put too much kava in the coffee, or the filter will clog up. An 8:1 ratio is probably okay.