I want to take a shot at a lager. I have read, that once primary fermentation is complete, leave the beer on the yeast cake to lager at 33F - 37F for 6 to 8 weeks. I have also read that you should move the beer to a secondary to lager. What would you recommend? I'm going to brew a 2.5 gal batch. Is one pack of dry yeast enough for 2.5gals?