I've had two big beers get stuck at about 60% attenuation...extract brews, OG 1.129 (1.7 gallon batch) pitched 11.5 g sachet S-04 (no rehydration), went like gangbusters until 1.050, then nothing...1.101 OG (1.7 gallon batch), used WLP007 w/1 L starter. Fermented down to 1.034 and stuck...