> found what I thought was white granulated pure cane sugar.
> happened to be at WalMart

I'd be very careful.

I suggest taking the "brown" bags back to Mall-Wart
for an exchange. Make Mall-Wart eat their problem, 
rather than your bees.

Here's a few things that may be of help:

Unless the bag clearly says "Pure Cane Sugar", you are certain 
to be buying beet sugar. Now, there's nothing wrong with 
feeding your bees beet sugar, because, despite what many 
may want to believe, the bees can't tell one form of sucrose 
from another. Beet sugar should be white also, so the source 
of the sugar would not explain the off color.

> the first bag was white the rest were off white
> obviously it wasn't totally refined

That would be very rare, given how the refineries work.
I'd be more inclined to think that it was contaminated with
something after being fully refined. Even "brown sugar" is 
almost always fully-refined white sugar that is merely 
sprayed with molasses after being fully refined. 
This article I did in 2003 may explain more fully:
http://bee-quick.com/reprints/sugar.pdf
> does molasses hurt bees ?

If you are correct, and it is molasses, it will not hurt,
as it is simply an indigestible component of the syrup, 
and will pass though the bees undigested. If the bees
can still fly during the time you are feeding fumagilin, and 
your only use for this feed is specifically for the application
of feeding fumagilin, then you likely can get away with it.

But we have no idea what the impurity might be, and I
assume that you'd rather not spend a few hundred bucks
on a lab to find out what the impurity might be, so I would 
NOT use this sugar for any sort of fall or spring feeding, as 
confined bees would be unable to digest the impurities 
(whatever they are), and you have no way to assure yourself
that all the feed you feed will be consumed before cold sets in.

Here's my best guesses:

a) Mall-Wart buried its ethics with Sam Walton.
 I wouldn't trust that company any further than
 I could comfortably spit a rat.

b) Note the 2008 hurricanes, and their tracks through
 places like Cuba, Dominican Republic, Haiti, Jamaica,
 and other sugar-cane-producing nations. Note that 
 in a hurricane, bags of refined sugar could get 
 soaked with anything, even if stored in a good 
 warehouse. (Wind shakes building, stacks of pallets 
 collapse, giant mess results, sugar is sold at salvage 
 prices to a wheeler-dealer broker, and so on.) 

c) The sugar might have been repackaged into new bags after
 being sold as "salvage" or scrap to a broker. "Always Low
 Prices" means "Always Lowest Quality". Did you think
 that someone was selling sugar below cost and hoping to
 make money by selling at a loss at higher volume?

d) Despite what you wanted to do with the sugar, it was being
 sold for human consumption, so any impurities might be
 cause for grave concern on a public health basis.

 

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