Possible Clues:

• Drink as, for instance, decoration is picked up
• It might be spiked
• Yule treat
• Seasoned (and seasonal) quaff
• Breakfast ingredient no good for alcoholic drink
• Drink for example that's good, then no good
• Gone around the horse for a drink
• Gone off to stable horse and get a drink
• Source of some December food poisoning
• Drink leading to awful grogginess - sir's completely out