Not wanting to make a plug, this being a .org site, palmer " how to brew". Don't remember how much sugar, but if I go to the chart in the Palmer how to brew book and matched the quantity, temp, and all that, it would give a number. That is how much I used. It was cane sugar, I think, although could have been dextrose because I had some around from my five gallon, all bottled batches. Temperature was around 70 F, right out of the fermentation freezer.
Just a btw, FYI, I have made several extract batches, bottling them and using dextrose from the local home brew shop. Never had this result. Of course, I did not have to determine anything from tables or formulas, it was all measured out as a predetermined recipe. My quess is that I used too much sugar, somehow miscalculating the amount. The beer is a little bit over carbonated - could be my imagination, since I am drinking so much from my kegs where I force carbonate. As a possible experiment I will let it condition for another week or so and see if the yeast takes care of things. Forgot to mention, it has been stored in a bedroom closet at room temp, around 75 F for the five weeks of bottle conditioning. WOW - so many variables, fortunately, great beer.