I believe the very basic 'idea' of Kopi Luwak is the wild luwak would only pick the ripe coffee beans for his dinner. When the luwak is put on cage and feed by human, then the 'luwak-picked coffee bean' is gone.
I believe there is another method where people would herd the luwak through the coffee plantation and let the luwak picks the coffee beans.
Certainly, the luwak ingestion track would alter the coffee taste, but ripe coffee beans also important.
It is worth to note that a wood from coffee tree makes a good alternative material for keris sheath. It has mild brown colour and smooth grain.
Well, at least I mention 'keris' once
