5th batch, first real problem

I ran into my first real problem today and I'm hoping I can get this one figured out.

On 3/25/2012, I brewed an extract batch of Northern Brewer's Dark Cherry Stout (http://www.northernbrewer.com/shop/dark-cherry-stout-extract-kit.html). Brew day went well, target OG was 1.053 and I hit it dead on. Clean and sanitized fermenter was waiting, filled 'er up, pitched one packet of Safale S-33 dry yeast (second time I pitched dry yeast directly on wort, usually rehydrated first). Fermentation was active within 12 hours at a temp of around 70F with kraused formed quickly. After active fermentation ceased on or around 3/28/2012, regular temps maintained around 66F.

Fast forward to today, I am prepping to rack this batch over 6 lbs of Vintner's Harvest Cherry Base (http://www.northernbrewer.com/shop/vh-cherry-base.html) and 4 oz cacao nibs (http://www.northernbrewer.com/shop/cacao-nibs-ghana-4-oz.html). The cherries and nibs are contained in a big nylon bag so they aren't loose in the beer.

I pulled a sample with my wine thief and the SG reading is 1.030. I have no idea what the FG is supposed to be for this brew as the directions from NB don't say but I'd like to think it's supposed to be lower than that.

It's been racked to secondary over the cherries and cacao nibs so there's not much I can do now. I don't plan to bottle this one, it'll go to the keg. My first thought was to pitch another packet of yeast over it (rehydrated, of course) but that is really the only option that I can come up with other than RDWHAHB.

My second thought was to skip the secondary bucket and re-rack it to the keg with the bag of cherries and nibs and leave it in there for an extended time frame, maybe even pitch more yeast in there. Not worried about oxidizing it as my racking technique is good and I don't mind moving it is needed.

I'm a bit concerned because the fruit will add fermentable sugar to the brew so it will increase the gravity. There's basically ZERO headspace in my bucket and it fermentation takes off, I'll definitely need to go to the keg.

Thoughts? Advice?

Attenuation numbers for S-33 are a little hard to find, and I've seen everything from 60-75%. That would put your target FG in the range of 1.013 to 1.021. S-33 also seems to have a reputation for sometimes being a slow fermenting strain, so you may have acted a bit early on the secondary transfer.

Since you've already racked it over, I'd be inclined to see what happens given the new sugars available in the cherries. You might prepare to rig a blow-off tube.

Thanks... I'm actually going to have to take it to the keg, my bucket can't handle the volume I've got in it. I can put it in the keg, purge the O2 with CO2, hit it with 30psi to seal and see what it does over the next 3 or 4 weeks. Sounds like a good plan?

Wait; so you added more sugars which you think might kick up the fermentation again and you are adding it to a sealed keg? This sounds like a bad idea to me. Am I missing something?

Sounds like a bomb in the making. Starting at 30 psi and adding lots of new sugar.

Don't seal it.

I had sealed it at 30 psi with a quick burst, purged, hit again, purged, hit again, purged, then hit it one more time.

I just purged it again but it should still be sealed. If CO2 builds up it'll be alright as it's basically the same thing as carbing in a bottle except bottles explode where I have a pressure relief valve that I can trip manually or it will trip itself if the pressure gets too high.

I also checked my hydrometer against water from my RODI unit. It's right on accurate so this leads me to believe that the 1.030 reading is legit.

As I see it, I have two options:

1 - Leave in the keg and see what happens over the next several weeks

2 - Leave in the keg and add some additional yeast to kick-start the fermentation again

Yooper or Revvy around to help a brother out?

Gonna leave it be for now unless I get some advice otherwise. Not really in a hurry but I did brew another batch tonight since my stock is running low and the porter is going to take at least another couple of weeks.

I've never heard of kegs with pressure relief valves that will open on their own when pressure gets to high but then again I don't really know a ton about kegs. If you have to do it by hand it seems risky and like it will need a lot of attention.

I think it would have been easier on you with a blowoff tube, then let it set a couple weeks with that yeast. Then Keg, but bah don't worry about it. RDWHAHB.

I'm curious to hear if the fermentation picks back up. Keep us posted.

There are plenty of threads describing the use of corny kegs a fermenters. Most describe pulling the gas post or pressure relief valve and replacing it with a air lock or blow off tube. Foam control drops are also recommended by some posters.

It will referment on those cherries, I have a chocolate/cherry stout in secondary now...it's not a vigorous fermentation but it does give you a little foam. I would just pull the vent on the keg a couple times a day to prevent pressure fermentation, your yeast don't need any more stress at this point.

That small amount of fermentation is no threat to the integrity of the keg, the CO2 would just remain in solution and carb the beer....but vent it so the yeast don't get stressed.

10-4. I'll pull the pin on it a couple of times a day. After about 2 weeks I'll check the gravity and see where we're at. If it hasn't dropped to an acceptable level then I'll consider pitching more yeast or something.

I pulled the pin yesterday afternoon and it had built up a bit more pressure. I forgot to pull it this morning. I wonder what is more likely: pressure is the result of off-gassing or new fermentation products?

I'll be keeping an eye on this one. Going to pull the pin again when I get home this afternoon. I wonder if there's a keg lid modification to include a pressure gauge or something?

Pulled the pin yesterday afternoon and pressure had definitely built up. Must be some krausen or something in there as well because I'm getting foam out of the relief valve after a bit.

Pulled the pin again this morning and very similar affect. Was able to keep it open for a bit longer than yesterday. I find that if I pull it up very slightly then I can keep it going for longer. If I yank it straight up then I get foam/beer out the valve very quickly.

New phase to this experiment... I got home today and relieved the pressure off the canister again. Getting tired of this so I'm moving to plan B.

I popped the handle on the keg lid to the open position. Knowing this thing is still under pressure, I gently smacked the edge of the lid with my fist a few times. I got a big spray that popped out of the keg and now it's just slowly leaking CO2. It's been hissing for about the last 5 minutes or so. I'm just going to leave it like this for the time being. Periodically I'll spray the lid down with StarSan to keep it nice and sterile but I figure there's not likely anything to go wrong here.

Why is no-one surprised at this!!!!!

Calder said:

Why is no-one surprised at this!!!!!

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Huh?

jaytizzle said:

Huh?

Click to expand...

You put a lot of sugar in it and sealed it. Of course it's going to generate pressure.

Well yeah, I knew it was going to. It's just messy because I filled the damn keg up too high. It's all good now, though. Hoping it kicked fermentation back off (looks likely at this point) and can push the SG a good bit lower.

Why don't you just leave the pressure relief valve open? Since you've been pulling it to relieve pressure, I take it you have a standard pull-type PR valve on a ball-lock keg, so pull it, twist the ring 90° and leave it there. Permanent open vent. Place a sanitized piece of foil over it to keep any undesireables from falling in (not likely to happen, but no need to take chances).

cmybeer said:

I've never heard of kegs with pressure relief valves that will open on their own when pressure gets to high but then again I don't really know a ton about kegs.

Click to expand...

I'm pretty sure that is precisely the point of a PR valve. It will yield and relieve excess pressure so the vessel doesn't explode. I believe with a corny the PR valve gives at around 60 PSI, well below the 130 PSI rated pressure of the keg itself.

I thought about leaving the PR valve open. I did for a little while yesterday. I may go that route. A piece of sanitized foil should be good enough to keep anything out, too.

And yes, LLBeanJ, that is the idea. They're certainly made so that they shouldn't explode in the event of a problem. Otherwise they'd be mighty damn dangerous!

It's been on cherries and cacao nibs for two weeks as of today. If you don't feel like looking back at the first post, I was at 1.030 before adding in the above.

I just checked the SG and I'm at 1.020 or 1.022. Should I call it done? I think my only two options are to either call it done or pitch another packet of yeast.

I just tasted the sample that I pulled and it's not bad... perhaps a bit sweet but that may be my imagination. I'm disappointed that there's almost no discernable cherry taste but the stout has very rich chocolate and coffee flavors and I do like it a lot.

Also, the cherries and cacao nibs are in there in a nylon bag. I think I should pull it before I put the keg under carbonation to serve but would it hurt anything to leave it in there? Kind of an odd idea but it just struck me...

Anybody got any ideas? If nothing else, I'll just pull the cherry bag and get the keg ready to drink.