Thanks for the correction! I listened to the interview with Vinnie Cirluzo on the BN over the week; he says that the commercial addition at 90 minutes is "generic hop extract." Originally, he said, it used to be CTZ (Columbus, Tomahawk, Zeus,) but he can't get that anymore.
I also brewed with extract, using this recipe
for my grain bill. I added the sugar at the beginning of the boil (as in the commercial example) but waited to add the extract until the last 15 minutes.
The color coming out of the kettle was a medium dark amber. Next time I might try an extra light extract, or use a lower L crystal.
I pitched from a starter, and the lid blew off my fermenter after about eight hours. It was only uncovered for about ten minutes before I got to it, and the krausen was going like CRAZY, so I'm confident that the yeast will defeat any possibility of infection.
The temperature has been kept at a steady 68*F.
I'm going to add my first dry hop addition on Friday, when I expect active fermentation to be complete.