Blue Mountain is both a Jamaican region and a Typica-derived variety, and they are frequently confused.
The variety
Selected in Jamaica from Typica stock, and notable for unusual tolerance to coffee berry disease — rare in a Typica descendant.
That tolerance is why it was exported: Kenya, Papua New Guinea and Hawaii all have Blue Mountain plantings.
The cup
Mild, balanced and exceptionally clean, with low-to-moderate acidity and a smooth body. Refinement rather than drama.
The confusion
A Papua New Guinean coffee grown from Blue Mountain seed is not Jamaican Blue Mountain, and cannot be sold as such. It may share genetics and taste quite different, because region matters as much as variety.
Brewing it
Filter at medium roast, gentle extraction. Its subtlety does not survive a very light roast.