Here is a link to an article about a study done in England in which varorized oxalic acid was determined to be the most effective method for controlling Varroa mites in honeybee colonies: http://www.sussex.ac.uk/broadcast/read/33537
Here is a quote from the article:
“It is almost too good to be true that sublimation, the best method for killing Varroa with oxalic acid, also has no harmful effects on the bees, and is the quickest to apply.
Well, things are finally winding down. A few remaining supers to be extracted, final feedings, medications to be removed and mouse guards to be placed. Maybe some repair work to be addressed and then to settle in to read over the winter. And one last club meeting to look forward to before the end of the year.
As usual, we will be meeting on the third Thursday of the month, November 19 at the Good Zoo, starting at 7:00 pm. Not to worry, Thanksgiving is the following Thursday. Thanksgiving?? Already?? Yesterday was Labor Day wasn’t it??
The conclusion is that crystallized honey is perfectly OK as it is, but if you really want to liquify it, do so with very gentle low heat. And the three things that make it more likely to crystallize are: