Originally Posted by gbx
I'm a first time user of this strain and I've got a second krausen on 1.037 bitter. At 9 days after pitching it was at 1.010 (predicted terminal gravity), the airlock had been essentially still for at least 4 days (one bubble in every 5 minutes) so I added the dry hops. 3 days later there is a second krausen, the airlock is bubbling every 3 seconds, there is hop bits and trub rising and sinking and the gravity was down to 1.008. Mash went fine, ferment temp has been a stable 21C. Is this how this yeast acts? Did i pick something up from the dry hops?
This is behavious is normal as far as British yeast strains go. Most of them are very flocculant and the yeast tend to either sink to the bottom in huge clumps or chill on the surface of the beer (1318, 1469, 1968, 1187 and other true top croppers exacerbate this behaviour).
I'd recommend fermenting in buckets if possible and rousing the yeast by "folding" the krausen with a spoon a few times in the first days of fermentation. What probably happened is the yeast flocced out before eating the last two points and that dry hoping roused them back into shape, hence the gravity drop. 1318 is a very docile and superb yeast strain but it needs a bit of rousing in my experience to get full attenuation. You can bottle as soon as gravity is stable and you feel the beer is ready, even if there is still a yeast mat on top. Top croppers will form a thick crust on top after 10 days or so that will pretty much never fall down in the beer. You just rack beneath it or throw it away come bottling time.
1.008 for an ordinary bitter is just about perfect I reckon. Expect fruity if your beer fermented at 21C for the whole way though, but fruity has its place in a good bitter !