Wyeast 1968 over carbonation

[verysupple]

Hi all,

I had a search around and found a few threads on problems with Wyeast 1968 but not the problem I have.

It seemed to ferment out OK (I hit my target FG and it stayed there for about a week before I bottled) but the longer it stays in the bottle the more carbed it gets. Now this in itself seems completely normal, but it's been in the bottle at room temp for about 7 - 8 weeks now and all the carb drops should have been fermented ages ago. There aren't any bad or off flavours developing so I'm thinking it's not an infection. I figure the yeast is still munching away on the sugars in my beer even though it stopped fermenting before I bottled it. Has anyone else had this happen with Wyeast 1968?

 

[warra48]

http://aussiehomebrewer.com/topic/69537-uk-liquid-yeast/

Same issue as I raised in this recent thread.
WY1968 was one of my culprits also, amongst others.

Have a read of my thread.
It should give you some good idea what's going on, and how to deal with it.

 

[Bribie G]

1768 (close relative to 1968) does this as well. I'm doing a run of 1768 at them moment. Keg beers turn out nicely attenuated but when I collect yeast cake in PET bottles and put them in the fridge I have to let off pressure every couple of days for a week or so, otherwise I get a gusher. I think the "problem" is - as I posted in Warra's thread re UK yeasts - is that many are evolved to continue fermenting gently in the cask to naturally condition UK real ale and not really intended for bottling maybe? UK bottled beers are overwhelmingly pasteurised so using yeasts like 1768 or 1968 for bottling is maybe outside their job description. I never get this problem with the likes of American West Coast style ale yeasts.

 

[verysupple]

OK, I read warra's thread and it seems to be a pretty widespread problem with a lot of english ale yeasts. I did swirl every day after fermentation slowed down. If a lack of oxygen is the issue, how could I solve it? If I just shake the FV all the head space will be CO2 anyway and won't help.

EDIT: Oh yeah, and thanks for the replies.

 

[RdeVjun]

Yep, as per Bribie G, seems to afflict 1968 and its cousin 1768 frequentlly, seems that under- attenuation is not uncommon and even though it has achieved the anticipated final gravity it slowly persists in eking out a little bit more when bottled. Annoys the heck out of me...

 

[chunckious]

I have just cold crashed a Mild with 1968, 1 point above gravity. It sat there for 3 days. How will this effect a kegged beer @ serving temps?

 

[RdeVjun]

Not at all chunkious, its really a problem for bottling where the ferment continues very slowly after bottling and leads to overcarbonation and gushers.
One thing that could be done is to reduce carbonation sugar, I've done that, even used none but results were mixed as it is difficult to predict just how it will behave. About the only other thing is to refrigerate once it reaces the desired level of fizz, but that's not always feasible either. I'm glad to be kegging now but I also do a few PETs for the comps where a gusher is hardly an impressive introduction to your beer.

 

[chunckious]

Not at all chunkious, its really a problem for bottling where the ferment continues very slowly after bottling and leads to overcarbonation and gushers.
One thing that could be done is to reduce carbonation sugar, I've done that, even used none but results were mixed as it is difficult to predict just how it will behave. About the only other thing is to refrigerate once it reaces the desired level of fizz, but that's not always feasible either. I'm glad to be kegging now but I also do a few PETs for the comps where a gusher is hardly an impressive introduction to your beer.

 

[chunckious]

Thanks heaps R. Thought that was the case. Catch up for a beer soon mate.

 

[warra48]

OK, if a lack of oxygen is the issue, how could I solve it? If I just shake the FV all the head space will be CO2 anyway and won't help.

It won't all be CO2, it will mix with oxygen if you stir or agitate vigorously enough.

 

[RdeVjun]

Yes, Warra is quite right, fermenter headspace is not really a concentrated CO2 atmosphere, nor is it low for O2. The extra CO2 from fermentation diffuses without too much difficulty, at least that is my understanding.
As far as solving this problem goes, introducing O2 after the ferment is complete is not advisable, nor after the ferment has progressed, only aerate in the initial day or two after pitching. Also ensuring yeast nutrition, pitching rate and initial health should all help, but I've never fully isolated the precise cause with this annoying issue.

.
OT: Yep chunkious, I'm always up for a beer after work!

 

[verysupple]

Yeah, I've done lots of seaching and nobody has a definite answer as to why it happens.

I've been listening to The Jamil Show podcasts and he's a big fan of 1968 so I dropped Jamil an email to see if he had any ideas. He replied by the next morning, which I didn't expect as I fugure he'd get a gazillion emails, he's a great guy. Anyhoos, his only idea was that maybe I got an infection at bottling, but I'm almost certain that isn't the case. After asking a mate, I'm pretty sure my oxygenation before pitching is fine.

I'm interested to know what pitching rates people used when they got the problem. I under pitched (1 smack pack for 22L at 1.054. Yeah, I'll do a starter next time) so as RdeVjun pointed out, it may be as simple as just pitching the right amount of yeast?

 

[Bribie G]

I've got two Mt Franklin water bottles of 1768 slurry in the fridge at the moment and I have to crack the seals every morning and let the gas out - they are slowly working even at fridge temperature. They are just about worked out now. I guess ultimately you could ferment in primary for maybe three weeks with rousing, but WTF if I was bottling and I had to do that, I wouldn't bother with that yeast, or 1968.

 

[RdeVjun]

Yep, I was wondering if the cause wasn't a common/ house infection, but if that was the case then all of my beers would have this trouble and they don't, seems to be isolated to just 1768, 1968 and 1187, never seems to be an issue with 1469, lager strains etc.
Thankfully I mostly keg now, but the comp beers are a PITA and I err on the side of undercarbonation.

 

[Online Brewing Supplies]

Its a tendancy for these high floc yeasts to drop out early in the ferment, I do as others have done for decades , beat the krausen back into the fermenting wort as you go.
Sounds simple but it works as the krausen is not working sitting on the top of the wort.
So as Michael J said "Just beat it " for a happy ending
Nev

 

[verysupple]

So I've learned a lot since I started this thread (about 3 momths ago). I've learned more about pitching rates and now make appropriate starters. I've also learned about oxygenation and now do better on that front too (I shake the McF*ck out of the FV before pitching). I also got in touch with Wyeast and asked it it's just a characteristic of this yeast to keep slowly fermenting/conditioning, as it's supposed to be a good cask ale strain, and they indicated otherwise.

Anyhoos, I've given Wyeast 1968 another go as I loved the flavour so much the first time, even if I hated the over carbonation. Approximately 50 hours after pitching my SG has gone from 1.046 to 1.012 (apparent attenuation of 74%) while at 20*C. At this stage the yeast look like they've dropped like a rock so I've roused it and will raise the temp slowly up to 22*C. Last time I managed 1.054 to 1.015 (72% AA) at a constant 22*C and I got massive over carbonation over a couple of months - I even had to recap 'em.

I'm taking everyone's advice and rousing the yeast and raising the temperature but is 22*C high enough to keep the buggers active? Or maybe temp isn't that big a factor and it's all about the rousing (as Gryphon advised)? I know at this stage of the game higher temps won't affect flavour much as most of the bad/off flavours come during the yeast exponential growth phase, but at the same time I don't want to raise it too high if I don't have too. What's the consensus?


P.S. Don't tell me to keg, SWMBO isn't gonna stand for more beer gear in our small apartment. And don't tell me "that yeast just does that" because the manufacturer states otherwise.

 

[BeerNess]

Subbed... I'm about to use this yeast for the first time, on an Ordinary Bitter then a Robust Porter onto the cake. Definitely sounds like some considerations need to be allowed for!

 

[verysupple]

I thought I'd post an update based on my experience with this yeast in case anyone comes across this thread when they encounter the same problems.

Well, I've used 1968 a few times since I last posted in this thread and the continuous fermentation in the bottle always happens. HOWEVER, since I've started cold crashing my bitters for about a week (I didn't used to cold crash at all) it takes a lot longer for the beer to become over carbonated. "Well, duh" you say. Yeah, even though it takes a little longer to carb up (a couple of weeks after CCing for a week at just below zero, whereas before it was about 3 days to carb up), the lower amount of yeast left in suspension is definitely extending the time it can be stored before it's over-carbed to a dangerous level (which is what I was getting before).

So, my advice for people bottling beers made with this yeast (and other strains that ar notorious for this problem) is to cold crash it real good to drop out as much yeast as possible, because it's just going to keep fermenting in the bottle (despite what Wyeast told me :angry: ).

 

[jr79]

Interesting to read this thread now as I brewed a mild with 1968 back in February. I knew it would be slow to carb up initially so waited a good 6 weeks before drinking, and it still seemed flat. I was cursing myself for underdosing the dextrose when I primed the bottles.

But wouldn't you know it... I left the rest to sit for ages, and sure enough they're now more than adequately carbed up nearly 6 months on (albeit not in quite as fresh condition flavourwise), far more than you could have anticipated from the initial tastings. Was getting rave reviews from the lads on our footy trip where I threw these in the esky to basically use them up, not expecting much from it.

I'm wondering if I should be careful the couple of bottles that are left don't blow... (they're in plastic thankfully). Perhaps I'd best just drink them quickly

 

[mash head]

Ive found conditioning in 2ndary for a couple of weeks (last 2 have been 3-4 weeks) brings the FG down a couple of points and allows you to carb to the style you want. So far so good any way. Ive only been using dry yeast but all the problems Ive had were with the English strains.