Rousing yeast

[DaddyMakesBeer]

How do I rouse a yeast that appears to have suffered premature flocculation? I say this cuz I had on OG of 1.072 and fermentation quit at 1.030. I expected a primary reading of no more than 1.020, though I quietly hoped for 1.015.

I'm not sure what happened. I aerated like crazy (30 minutes with a filtered aquarium pump) and pitched a starter that had been steeped up once. I used Wyeast 1275 (Thames Valley). Truth is, I've had this happen three other times over the years with English yeasts. Never, however, with the 1056 Chico strain.

So, what to do about it? I've seen references to "rousing" the yeast, but that sounds like I need an alarm clock with a snooze button. Aerating the wort again seems like a bad idea (unless you like the flavor of cardboard).

Suggestions, anyone?

[Tweek]

what I do is I take the airlock off of the carboy, but I leave the cork. Then with a clean hand or object, I plug the hole in the cork. I then pick up the entire thing and give the carboy a gentle swirl until I get all the sediment back into suspension. This will work if the yeast has just gone dormant for some reason but is still viable.

other things to try if rousing doesnt work would be to add some yeast energizer, or some yeast hulls or even some sort of enzyme such as a pilsner enzyme. All of these things can be purchased at your local brew shop and I have tried them all with success.

[DaddyMakesBeer]

Good idea. Now, here's the kicker: Any reason not to do it if I already racked to my secondary? Can't really think of any. There's plenty of yeast in the carboy. Only thing missing is the trub.

[Tweek]

nah. no reason to not give it a try in the secondary. In fact the only time I have ever tried it was once it has gone to secondary. If fermentation stopped in your primary at that gravity you would have a whole new set of problems.