A few years back I focused on brewing an award winning tripel. My first attempt I added all the cane sugar to the boil (2.5#) and the beer finished at 1.022 even with champagne yeast added. My second attempt I did the same (stupid me) but made sure to calibrate my thermometer properly thinking my thermometer was to blame. Still ended up with a 1.020 FG.
Third attempt was the charm. Only added .5# to the boil, then at day 5 or 6 added half of the remaining sugar and 2 days later the rest. The beer finished at 1.012! Perfect. And it was an award winner...ABOUT TIME! So, I will never add anymore than 1# of sugar to the boil after my learned experiences. Now off to brew a Belgian Golden Strong!