Is honey still good if it is hard?

Honey is naturally anti-bacterial and anti-fungal and will not go off unless you dilute it with water then let it stand, in which case it will probably ferment. Sealed jars of honey have been found in Egyptian tombs. They were opened and tested, and the honey inside, although set, would still be edible -- after thousands of years.

As for hard or soft, honeys vary according to the types of flowers from which the bees have been collecting nectar.

Nectar is quite a complex mixture of sugars, mainly sucrose, fructose and glucose, though often there are other sugars in the mix. Enzymes in the bees' saliva break the complex sugars down into simple sugars, mainly fructose and glucose. The proportion of these two can vary.

All honeys start as liquid, and all honeys will set -- eventually. Honeys with more glucose than fructose will stay liquid for a long time, but if the fructose predominates the honey will set more quickly, often within days of extracting from the comb.

Nutritionally, there is absolutely no difference between liquid honey and a set honey. Also, a previously liquid honey that has started to crystalise has not 'gone off', it is just starting to set. If you want to re-liquidise it, put the jar in a bowl of warm water -- no hotter than you can bear to keep your hand in. It may take a little time, but the crystals will dissolve again.