No, that’s not the Blob that ate the brewer. A mixture of diatomaceous earth and yeast. DE is used for filtering. Picture from Wiki Commons
Written by Brad Smith for Beer Smith
Note: Professor GA does not recommend washing and reusing yeast that you bought in a dried form. Drying yeast stresses it. Best start with a new yeast if it was dried.
Washing yeast to reuse it in another batch of beer is a great technique to have in your home brewing arsenal. Yeast washing is a simple process used to separate the live yeast from the underlying trub (hops and spent grains) left at the bottom of your fermenter when making beer.