Checked my Hydrometer; Airlock is Rebubbling.

[reim0027]

I am on Day 4 in the Primary (Liberty Cream Ale). The airlock has been silent for a few days (not a big deal, I know). I checked my Hydrometer reading, and it is 1.016 (OG 1.048). About 1 hour after I resealed the primary, the airlock started bubbling again.

The beer looked normal in the fermentor. It looked like it was still fermenting. I did not knowingly agitate the yeast, and the temperature has not changed more than 1 degree.

My yeast's projected attenuation is 63-70% (WLP02). I am currently at 67%, if my calculations are correct. The beer tastes like beer, hoppy, mildly sweet, and flat.

Can someone explain why the airlock suddenly is bubbling again? I am curious, because I like to understand brewing.

 

[Parker36]

Probably just has to do with the different densities/temperatures of the air in the deadspace that got changed when you took the lid off. Happens, no big deal. Just remember what airlocks are for (hint: doesn't have anything to do with gauging fermentation) - but I gather you know that since you are taking hydro readings

 

[histo320]

THe same thing happened to me the other day.

 

[reim0027]

Ah yes, temperature change. I didn't think of the new air causing a change in temperature. The thermometer on the outside of the primary didn't change much, but that doesn't always mean the inside temperature didn't change (gotta love the insulating properties of water). So, I let out some of the heat, and now more CO2 is coming out of solution. Makes sense.

I have to admit, I love to see the airlock bubbling, but too often it is meaningless. I think airlocks are just for show.

Now that I know I have almost reached my max attenuation, I'll just let it sit for a couple of weeks, let the yeast finish and clean up. Then, I'll check it when I rack to the secondary (after 3 weeks in the primary).

Thanks!

 

[Nurmey]

When you took the sample you knocked a bunch of CO2 out of your brew. It happens with the slightest movement.

 

[reim0027]

Good to know for future batches - thanks

 

[HIT_MAN]

I wish I saw this thread before I made a thread just now. My brew is doing the exact same thing.

 

[reim0027]

I wish I saw this thread before I made a thread just now. My brew is doing the exact same thing.

That is funny. At least we are on the right track, and both learned something today.