[TokarevM57]

....verrrrry interesting, laddie....
something to find interesting.... from a popular on-line dictionary.....in truth I do enjoy a dram or two of SCOTCH whisky from time to time....distilled and bottled in Scotland by SCOTTISH craftsmen.....

“Scotch is generally used in compounds (such as Scotch pine or Scotch whisky), and set phrases. Scottish is the preferred adjective; in cases where you are referring to the literature, character, or ancestry of the people of Scotland, it is generally correct to describe them as Scottish.”

[Dr. Sivana]

Now you made me have to bring out the big guns.

My print edition of The Oxford English Dictionary has Scotch as the dominant usage except for formal speech. Used by real Scotch poets like Burns, etc. (See lines marked with red in margin).

http://sittnick.net/scotch_1.jpg

zoomed version

If you want an American dictionary, my 1968 World Webster's Unabridged (fake Webster's) is still serviceable:

http://sittnick.net/scotch_3a.jpg