The following has kindly been contributed by Mary Hill, one of the BBKA Honey Judges:
The first thing to do is to understand how granulated honey is different from soft set honey. Granulated honey is honey which has been extracted and after filtering is put straight into jars. It is NOT stored in tubs, melted and put into jars or mixed with other honeys before jarring.
The decision to produce good granulated honey must be made before extraction starts.Having made this decision make sure you extract the honey on a warm day straight from the hive. If you have to store it keep the supers in a warm place. Honey which has some rape nectar in it gives a finer grained honey.
After extraction the honey must be filtered through the finest filter you can find. Very fine nylon or a polyester fabric. I use a Strainaway with 100x100 filter. These are not made any more but you might get one secondhand. For smaller amounts Lakeland Strainer Jug is very good, but again this is out of production.
Store the honey in a settling tank overnight. Estimate how much honey you have and decide that the first third is going to be your very good honey. Wash the jars in hot water and let them drain dry. If you use a drying cloth make sure it is not fluffy.
Fill the jars so that there is no gap between the top of the honey and the bottom of the lid. Store the jars on a LEVEL shelf.
After three days remove any scum that has risen to the surface by placing a piece of clingfilm on the surface to pull off the scum. Put the jars back on the shelf and wait for the honey to set. You don't need to do anything else. The quicker it sets the finer the granulation will be.
When it has set do not worry about any frosting that occurs, this is a natural process. In a show the only penalty would be if someone had honey as good as yours but without frosting.
Before entering in show carefully check all over the jar for "foreign bodies", most of them will be on the bottom. Granulated honey that is clean ie no black dots will win a prize because not many people plan ahead. Make sure that the lid is clean inside.