Today I pitched 2.5 gallons of a sour complete with trub and yeast cake into a 2.5 gallon simple brew with 5 pounds of 2 row........ the sour was nearly a week in the fermenter and had stopped many days ago. The result was phenomenal........ Within one hour it was "popcorn farts"........ You couldn't hear the individual bubbles, it was like a machine gun!! The object was to dilute the sour. It will be fermented out in less than 24 hours. There's a LOT of energy in that yeast cake!!
H.W.