Glenfiddich Perpetual Collection Travel Retail

The Glenfiddich Perpetual Collection Retail Travel Exclusive, explores a method of perpetual maturation. Similar to a solera system, the vats of whisky are only half emptied for bottling, while the remaining aging malt is topped up with younger spirit, creating a continuous flow between the original liquid and those that follow.
VAT-01:Matured in a combo of bourbon and red wine casks (NAS)
VAT-02:Aged in Spanish Sherry casks,in the style of classic Spanish sherry soleras.(NAS)
VAT-03:Matured in sherry and bourbon casks for 15 years.
VAT-04:Aged in oloroso sherry and bourbon casks for 18 years.
(https://www.masterofmalt.com).
The entire collection is artificially colored to achieve the tones of whisky.
That is a common practice with scotch whisky.
The German phrase on the back label: MIT FARBSTOFF, proves it.
Apart from that. Are excellent,
The three little books were written by Scotch whisky reviewer: Ralfi.
I recommend his channel: https://www.youtube.com/user/ralfystuff