If hives need feeding late in the fall or during winter, sugar syrup should not be used, as the extra liquid may promote dysentery.  Too much moisture in the hive can also chill the bees.  Rather, fondant or sugar paste should be used (see recipes at the links below; however, some beekeepers recommend against using high fructose corn syrup in the fondant).  Alternatively, commercial fondant (icing base) can be used if it does not contain cornstarch, which is not digestible by honey bees.

Fondant can be used in two ways in the hive:

• To provide a carbohydrate reserve for the hive, place the fondant patty on the top bars of the top super of honey, so that as the bees move up through the hive over winter, they move closer to the fondant.  On days when the temperature allows, the bees will come up to feed on the fondant if they need it.
• For emergency feeding, place the patty directly over the cluster.

In either case, cover the upper side of the fondant patty with waxed paper to retard dehydration.

http://www.bamboohollow.com/fondant-recipe.php

http://en.wikibooks.org/wiki/Beekeeping/Recipes_for_the_Bees#Fondant_Bee_Candy