I emailed this to the Mr. Beer beermaster, but I figured I'd ask here as well.
For my Doppelbock 7.0, this Sunday will make it 3 weeks in the keg for fermentation. The previous beer I made was a pale ale, and I let that one ferment 3 weeks also, and waited to bottle until the surface cleared up. The doppelbock krausen cleared up after about a week, and at about the 1.5-week mark I noticed the surface was speckled with a lot of bright white spots. I assumed it to be yeast colonies, but unlike the yeast colonies for the pale ale, these spots haven't changed since I noticed them. They haven't grown or shrunk. Is this yeast? Is it bacteria? Should I wait to bottle it until it goes away? Is the beer infected? I tasted it, and it didn't have any horrible flavors, though I did notice a decent amount of hop particles in the glass. Is that something that will settle as I bottle condition it? I have been able to keep the temperature between 66 and 68 degrees throughout, except that the first 2 days it was at 56 degrees.