Stan- I heat my honey to 140 degrees F. I'm not sure how long it remains
in the sumps(3), but when it reaches the last pump the temp has gone to
140-142 degrees. The honey remains in the bulk tank overnight to cool
down, and let the air settle. I sell about 250,000 lbs a year, and have
no problem with crystals. Of course once it has been packaged, it must
be kept in a heated room, unless it can be kept frozen(unheated shed in
winter).
    As far as killing yeast spores-why? Yeast won't grow in properly
cured honey - will it?

Mike