>I have no experience with drums, but good experience with a gallon. I
>found a gallon of syrup left over from last year and it was fermented,
>thin, and had mold. All I did was boil it. Tt thickened and was
>readily taken by the bees. I presume the boiling killed the mold and
>evaporated the alcohol.
 
I thought that boiling sugar syrup caramelizes the sugars and gives the bees
dysentery.  Not the sort of thing one would like in winter feed.
 
But hey, if you WERE going to boil a barrel of fermented syrup why not
thread an adapter and some copper tubing into the little bung hole and pass
it through some cold water....   :)