Yeast dormancy/reactivation

[kahunaman]

Just want to clear something up..

When your beer hits a certain temp - whether in bottle or in lagering vessel (lets say 40 degrees) - the yeast doesn't actually DIE - it just goes dormant, meaning that when it comes back to fermentation temps for the strain some if not all of the yeast will wake back up correct? (or at least - it should?!)

My question is both for what if I put bottles into the fridge too early and need them to carb up more - will pulling them out help or is it all ready too late?

AND - is there an issue with lagers carbing in the bottle after being at that cold temp for so long?

Thanks, and merry xmas.

 

[menschmaschine]

For practical homebrewing purposes, the yeast will only die (outside other harsh conditions) if frozen. And by that I mean the solution they're in actually turns to a solid. (One can "freeze" yeast in a glycerin solution which doesn't solidify at normal freezing temperatures and they'll still "wake up" when exposed to optimal conditions).

So, sure you can remove bottles from refrigeration that haven't carbed up all the way and they will carb up. You may want to agitate them a little to get yeast back into suspension.

And speaking of yeast in suspension, the only effect lagering will have on the yeast is that, the more lagering time, the more yeast drop out of suspension. (Disclaimer: yeast can die over time (autolysis), but it takes a pretty long time.) At some point, if lagering went on for months, so much yeast could drop out of suspension that there won't be enough to ferment the carb sugar in any kind of reasonable time. So, I use the 6 week rule. Anything lagered over 6 weeks gets a 1/4 to 1/2 packet of dry lager yeast in the bottling bucket. I've lagered several batches for 6 weeks and they carbed up fine, although one batch seemed to take an extra week to carb up. However, when I do lager for 6 weeks, I agitate a little yeast into suspension from the bottom of the lagering vessel to be safe.