Barleywine: Fermentation restarted in secondary

[stricklandia]

This seems to be a common issue, but I wanted to post about my specific circumstances to get advice. I brewed a barleywine, and after close to a month in primary (well after specific gravity had leveled off at 1.027), I racked to secondary and dryhopped.

It's been in secondary for about a week, and I just prepped everything for bottling, only to find out that fermentation restarted. I took a gravity reading, and it's at 1.025. I'll wait a couple of days to take another reading to see if it changes, but since it was at 1.027 when I racked, clearly there's activity (it's also bubbling about every 18 seconds).

The temperature in the house is pretty steady at low 70s, but it's been hot the past few days (close to 80 in the house). Would such an increase in ambient temperature be enough to restart fermentation? Seems unusual for it to have restarted after so long. Also, what could happen if I bottle now? Potential bottle bombs? Or would it likely be okay?

After this batch, I might just take a break from brewing until the fall, when it cools off a bit (I'm not interested in upgrading equipment to give myself more temperature control until I have more experience).

 

[stricklandia]

Also: if I do just leave it to do its thing till fermentation stops again, is over-attenuation a risk?

 

[stricklandia]

Anyone? Bueller??

 

[Irishbrewer11]

With high-gravity brews patience is a must. What often happens with high gravity beers is the yeast begins to die off because of the alcohol content. When the yeast cells die they fall out of suspension and often take live yeast cells with them. When you rack into a secondary you inevitably introduce oxygen into the beer, albeit a tiny amount. This oxygen encourages the remaining live cells to reproduce. You end up with a dose of new live cells that are strong enough to resume fermentation.

Start taking gravity readings every couple of days until it is stable again. Then you are likely safe to bottle.

Over attenuation is a non issue in a high gravity beer. The high alcohol toward the end of fermentation will prevent the yeast from over consuming the sugars in your brew.

 

[Big_Belgian]

I've been reading a fair bit about barleywines recently and brewed one on Sunday. Everything I'm reading recommends a long secondary - several months at minimum. Why not just store it away in the coolest, darkest corner of your house and let the yeast fully run its course? As I understand it, the yeast still has lots of work to do even after "active" fermentation stops, and I think it is generally best to let that happen in the fermenter rather than in the bottles. I would set up a cheap swamp cooler if possible, or wrap it with cold wet towels - refreshed every couple days - to keep the temp down and just let it go through the summer.

 

[zepolmot]

I would suspect that the warmer temps were driving more CO2 out of the beer and that the change in gravity you're seeing is within the noise of the instrument, especially since you'll have to correct for the different temperature.

 

[NordeastBrewer77]

I would suspect that the warmer temps were driving more CO2 out of the beer and that the change in gravity you're seeing is within the noise of the instrument, especially since you'll have to correct for the different temperature.

This and dry hops can release air as they soak up beer. I often get increased activity after dry hopping. Make sure your FG is stable and bottle or keg.

 

[stricklandia]

Thanks for the replies. Fermentation still seems to be going; latest measurement (and yes, I am correcting for temperature) is around 1.023. I'm fine with leaving it till it stabilizes, but am a bit concerned about the ambient temperature (beer was about 77-78 degrees last time I measured the gravity). Does this temperature present any risk?

For what it's worth, it tastes fantastic (especially for only my second brew).