Coffey Stills are one of the more modern forms of distillation. And while having since been approved upon, Aeneas Coffey’s Design is somewhat the last of the old style stills that predate the modern stills of today. Building a tower, it distils and cools the alcohol and aromatic compounds more effectively, than a pot still, without the need to clean between each batch.
With the Grain it is actually down to the skill of the distiller to determine the strength and characteristics present in the whiskey.