Old Speckeld Hen Clone

[mrhardware]

Had a strange thing happen today.
Brewed an old speckled hen clone on the 29th and it went off like the clappers starting gravity bang on 1.054.
I have had it in a fermenting fridge at 18c and it was going great guns then it slowed to a crawl.
It went well over 10 to 14 day schedule but finally it hit a stable gravity at 1.008 which is 2 points above what i was expecting but gave it 4 days with no change and no activity in the airlock.
Cold crashed fridge to 1.5c and left for 24 hours, Prepped bottles for bottling and upon opening the fridge the beer was fermenting again an the airlock is blip-ping about once every second.
Do you think i should raise the temp again back to 18c or leave at 1.5c and let it ferment out until it stops monitoring the gravity ?.
The yeast used was an NBS ale yeast so was expecting it to have gone dormant at these temps.

 

[RoomWithABrew]

Are you sure that blipping was not in reverse, when you cold crash it will draw air in if you haven't compensated for that. I expect you have pulled air in during cold crash and have started the oxidation.
I would normally seal my pressure fermenter and make sure it had positive psi before cold crash to avoid this. THere are ways to compensate on other vessels using " balloons " filled with harvested CO2.

 

[mrhardware]

Are you sure that blipping was not in reverse, when you cold crash it will draw air in if you haven't compensated for that. I expect you have pulled air in during cold crash and have started the oxidation.
I would normally seal my pressure fermenter and make sure it had positive psi before cold crash to avoid this. THere are ways to compensate on other vessels using " balloons " filled with harvested CO2.

Thats what I thought at first but no it was definitely blowing out not sucking in

 

[user 18729]

Dissolved CO2 coming out of solution would be my guess

 

[mrhardware]

Never thought of that... Would it be the best idea to get it into bottles ASAP or give it a few more hours to see it airlock activity subsides.

 

[user 18729]

Never thought of that... Would it be the best idea to get it into bottles ASAP or give it a few more hours to see it airlock activity subsides.

I’d trust your hydrometer cold crash it as planned and then bottle it

 

[RoomWithABrew]

@Hopsteep
this activity is with it cold crashed to 1.5 celsius.

"Cold crashed fridge to 1.5c and left for 24 hours, Prepped bottles for bottling and upon opening the fridge the beer was fermenting again an the airlock is blip-ping about once every second. "

 

[user 18729]

@Hopsteep
this activity is with it cold crashed to 1.5 celsius.

"Cold crashed fridge to 1.5c and left for 24 hours, Prepped bottles for bottling and upon opening the fridge the beer was fermenting again an the airlock is blip-ping about once every second. "

I took “Cold crashed fridge to 1.5c and left for 24 hours” to mean he set the fridge to 1.5 degrees and left it go for 24 hours (probably not long enough for the beer to drop to 1.5 degrees unless it’s a small batch or a really good fridge).
Either way, if the beer is at 1.5 degrees (or close to it) the airlock activity won’t be any fermentation as the yeast will be dormant. I’m no expert but in my experience it’s probably dissolved CO2 from primary fermentation