I feel like making a big lager is one of the hardest things. Brewed a bock from Brewing Classic Styles, pitched lots of healthy yeast, got off to a good start, and I checked my gravity today hoping to see 1.018. Instead I saw 1.04. It has been going about 1.5 weeks at 49-50degrees. It's bubbling pretty slowy. Still a lot of gunk on top. WOUld you all increase temp to activate the yeast? Add oxygen? Need some serious help!