First off, All known goblin food/items use all 8 slots, incluing one strange piece.
Goblin bread uses 7, and no drink uses more than 5 items (only one being Cursed Beverage, the rest use 4 or less). Personally, I believe that the recipe will use 5 or less items. However, I also believe it'll be synthable with items that were in game
when the drink was introduced, ruling out Moval. water, and therefore I don't think that recipe is legit. However, the fact that it DOESN'T use 8 items definately doesn't mean it's fake; quite the opposite in my opinion.