Originally Posted by Fetus
I think it depends primarily on the yeast, with some other variables affecting it as well.
I don't think it depends "primarily" on any one thing.
I have a pale ale recipe that I make every 4 weeks. I always use the same yeast (US-05) and the recipe is 99% identical every time I make it. About 6 months or so ago, i decided to lower the ambient temp of my fermentation fridge from 66*F to 62*F.
Using the same yeast and the same recipe, but lowering the temp 4*F caused a massive change in krausen. I used to get an inch or two of light 'soap suds' looking foam on top. But now I get 4" of gooey slimy looking stuff.