Fermentation restart in secondary?

[Magnew]

I brewed a pilsner. Sat in primary at 48 degrees for four weeks. Finally transfered to secondary. It's been there two weeks today at 48 degrees. Took a hydrometer reading at one week in secondary and was already at FG of 1.011. Wanted to let it sit a couple of weeks. Yesterday I started to notice new little rings of fine bubbles appearing on the surface. Is it normal to get some renewed activity in secondary with a lager?

[Stodbrew]

I suppose its possible if the yeast was roused during transfer and if it has warmed up a bit.

[Magnew]

Yeast may have been roused during transfer, but that was two weeks ago, and it has been doing nothing for those two weeks. I have a bucket of water next to the fermenter with a thermometer in it. The temp has been pretty constant at 48 degrees. Now that I think about it, I did scoot the carboy over a couple of inches a few days ago...maybe I roused some yeast?

[Stodbrew]

I'm thinking that was probably what it was. Even if it is fermenting a little more, it will be negligible, and won't affect the beer much at all.

[Fast_Eddy]

There's also a very good chance that you've just liberated some of the remaining in solution CO2. I doubt that you'll find a change in gravity.

[Magnew]

So yesterday I took another reading (two weeks in secondary). In the last week it went from 1.011 to 1.010. Not a huge deal, but tells me that fermentation is maybe still not finished. Could account for the little lacy bubbles. There are more of those... and airlock bubbles have slightly increased. (although they are still REALLY slow)

The reading sample tasted better than the first one though.

[Tweek]

do you have much trub at the bottom of the fermenter? sometimes if you have a fair amount when it break down it can cause a very slight bubbling as it releases gas.

[Magnew]

There is maybe a half inch or so at the bottom of the fermenter. I believe everything is okay with this, I've just never seen one start bubbling again after sitting for two weeks with nothing.

[Magnew]

So this got kind of weird. By the time I went to bed last night, the entire surface of the beer was covered with white foam and the airlock was pretty active, as if I had real fermentation starting again. This morning it's all gone. I was going to bottle this weekend, but now I'm not so sure. I need the carboy though, I have another batch that is about ready to rack to secondary.

[Fast_Eddy]

Originally posted by Magnew
So this got kind of weird. By the time I went to bed last night, the entire surface of the beer was covered with white foam and the airlock was pretty active, as if I had real fermentation starting again. This morning it's all gone. I was going to bottle this weekend, but now I'm not so sure. I need the carboy though, I have another batch that is about ready to rack to secondary.

Sometimes late fermentation is a sign of infection.

[Magnew]

I fear that, but I am very careful. The only infection source would be my wine thief, but it was soaked in bleach solution and rinsed prior to taking samples. What should I look for if I taste another sample?

[Fast_Eddy]

Originally posted by Magnew
I fear that, but I am very careful. The only infection source would be my wine thief, but it was soaked in bleach solution and rinsed prior to taking samples. What should I look for if I taste another sample?

Taste it - if it's infected you'll probably be able to tell. If not, then it could just be one of those weird things.

[Magnew]

I took another sample today. gravity had not changed since last week despite the brief spat of fermentation. Actually tasted better than the last one. I believe I am safe from infection and have just experienced an FBO (Freak Brewing Occurance). Bottling will occur this weekend.