This sounds unusual. Tuesday night I brewed an Amber Ale, SG 1.070, pitched an appropriate starter with 1056, and stuck it in the swamp cooler. Yesterday morning it was chugging along wonderfully, though the kraeusen probably never broke an inch all day, probably not even half an inch. The temps, I'm pretty sure, stayed within 66 to 69. It may have peaked slightly at 70 for a short while, but I doubt it. By this morning everything was winding down, and tonight the kraeusen is all but gone. The hydrometer reading shows 1.023, but now there is a faint sulphur smell coming through as well. This means the yeast is stressed out, right? Does it sound like anything went wrong? I'm a little nervous because I planned on using the slurry for a big Imperial Stout.