You can feed it to your bees and they should have no problem.. If you are still worried about it, since it is only a couple of gallons you can strain it thru a cheese cloth.
We always have some syrup on hand and sometimes there is a little mold floating. Not a big deal..
Skim the mold off it you don't want to look at it but it will in no way harm the bees, only to some folks sensibilities. You might consider adding a cup of Clorox which will kill the mold and have no effect on your nucs. But nothing is necessary and the bees will take it if they have no natural nectar source.
A forum community dedicated to beekeeping, bee owners and enthusiasts. Come join the discussion about breeding, honey production, health, behavior, hives, housing, adopting, care, classifieds, and more!