Starting to wonder about my Porter and its secondary fermentation

[Hwk-I-St8]

I've been brewing pretty much just IPAs and PAs since I got back into brewing in March. At the beginning of July, I brewed a moderate porter (OG of 1.078) and pitched a nice starter of WYeast 1450.

The primary ferm seemed to go well, but after 2 weeks the gravity was at 1.030. I racked to a secondary which is a corny keg with a spunding valve (I plan to pseudo-BA this will oak cubes, bourbon and vanilla beans).

I noticed right away that the pressure was climbing to somewhere between 2.5 and 5 psi every 12 hours or so (I've been dumping the pressure twice a day).

After a week I took a sample, gravity was down to 1.022 and the expected FG was 1.021. Clearly fermentation resumed (or continued though there were no signs of fermentation when I racked to the secondary). I'm still seeing the same pressure rise every day almost a week later. Is it normal to have this ongoing extremely slow fermentation? I sampled the 1.022 gravity sample and, being paranoid, thought I tasted a metallic twang. I'm wondering if I've got an infection that's working on residual sugars.

My original plan was to add the bourbon/oak/vanilla this weekend, but I think at this point I'll give it a couple more weeks to make sure the flavor is worthy of the expensive bourbon and vanilla.

Thoughts?

 

[20grit]

First off... Moderate at 1.078???????? I must be drinking some puny porters.

Get some other people to taste it. It's obvious that you're expecting something to be wrong, so you're looking for flavors. Don't tell them anything specific about the flavors you've encountered. Just see what they diagnose.

Did you change the location of the beer when you racked? Warmer temperatures?
Are you sure you hit your mash temperatures as planned?

 

[bolus14]

This has been my experience when I used WY 1450, seems to slow down, or stop, somewhere between 1.025-1.030. After a couple of batches that ended up over carbed in bottles I figured out that raising the fermentation temps to 70-75 allowed it to finish up and usually got around 5-7 more gravity points out of it.

As for the metallic taste, I wouldn't worry too much at this point, let the yeast "clean up" for a few days to a week and then taste like you plan to do. I would bet you'll see an improvement in the taste and can move on with adding the bourbon/vanilla.

 

[flars]

I've had a similar with WY 1332. Bottled a porter at 1.014. Four months later the SG was measured at 1.007. I didn't have any bottles explode and was able to degas the remaining bottles to get a decent carbonation level.

 

[Hwk-I-St8]

First off... Moderate at 1.078???????? I must be drinking some puny porters.

Get some other people to taste it. It's obvious that you're expecting something to be wrong, so you're looking for flavors. Don't tell them anything specific about the flavors you've encountered. Just see what they diagnose.

Did you change the location of the beer when you racked? Warmer temperatures?
Are you sure you hit your mash temperatures as planned?

OK, it's a pretty big porter...probably really more of a stout (though the recipe I modded was for a porter).

I used fermentation temp control and fermented at 66. Raised to 70 as the initial activity seemed to subside and left it there for about 8 days. The secondary is just sitting in a corner of my basement, which runs cool enough year around that we pretty much all have a blanket on when watching movies in the basement. The activity of racking may have roused the yeast some though....

Mash temps were a bit lower than planned (was shooting for 156, got 154). The thermometer calibration has been checked periodically, including a week after that.

I'm probably paranoid, but we'll see what happens. I assume I should eventually get to a point where the pressure stops building if everything is in good order. At that point, I'll sample, take a gravity reading and decide whether or not to add the bourbon/oak/vanilla. At least that's my plan unless someone has a better idea.

 

[Hwk-I-St8]

More than a week later and it's building up pressure as fast as ever. This thing will not stop. It's now been a month and the thing is still actively fermenting. Really starting to wonder now. I'll pull a sample this weekend to get a gravity reading and see what it tastes like.

If it's not something wrong, best case scenario it will be a much drier beer than I planned for.