|Krausen along the edge|
krausen - noun, The foamy rocky head of yeast that forms at the peak of fermentation. (about.com)
At the bottom of the bucket, under the beer was about an inch of trub. It was thick and messy. I emptied it out in our compost pile.
trub - noun, "...the layer of sediment that appears at the bottom of the fermenter after yeast has completed the bulk of the fermentation. It is composed mainly of heavy fats, proteins and inactive yeast." (wikipedia)