Gravity issues from out of nowhere

[kaiserben]

I seem to have developed an issue where my ferments are getting stuck, or something ...

I'd previously had dozens of successful ferments.

All dry yeast strains (M44 most of the time), usually just the single packet, sprinkled, fermented at ~20C in a insulated chamber, no temp control, primary only, for 12-14 days.

I got complacent/cocky and never bothered to check gravity until everything was packaged into bottles.

But for 4 of my last 6 batches gravity has finished too high.

1. First hint was a Milk Stout using 2 x packets US-05 starting at 1.063. It began bubbling furiously within 24 hours. I bottled it after 18 days in primary but it was 5 points higher than expected (1.024 instead of 1.019). No big deal, I thought, it was the first time I'd used lactose and thought maybe BeerSmith 2 didn't get calculations right, or something.

2. Second time was a American Pale Ale using 1 x packet M10 (first time I'd tried M10) starting at 1.055. I added dry hops on Day 9 and bottled on Day 12. OG was higher than expected (1.055 instead of 1.051). And FG was way off (1.024 instead of 1.014). I put this down to an anomoly and wondering if it was the yeast I hadn't used before.

3. Then I made another Sweet Stout (and turned it into a Creme Brulee Stout) using 2 x packets S-04 starting at 1.071. I'd carmelised 250g white sugar and added that to last few mins of the boil (included this in BeerSmith). This batch had a huge flow of krausen out of the airlock. On Day 7 I added a vanilla bean/vodka mix to primary. And it was bottled on Day 14. Finished at 1.032 instead of 1.021.

4. A bit unsure of myself, but not overly concerned at this stage, I went back to a trusty recipe I'd made many times before. A "session" IPA using 1 x packet of M44. Starting at 1.055. Transferred to secondary fermenter and dry hopped on Day 14. Bottled on Day 17 with FG of 1.030 instead of 1.011!!! Yikes!!!

Any thoughts on wtf might be happening?

I'll start doing some simple things, like rehydrating the yeast, but surely all those gravities, pitching rates and ferment temps are nothing out of the ordinary for sprinkled dry yeast???

EDIT:
Measured with hydrometer at ~20C. Hydrometer reads correctly in tap water.
And in amongst those brews I had 2 others, another session IPA and a 6.3% American Amber, almost exactly right on OG and FG.

 

[NewtownClown]

you don't indicate what you are measuring your gravities with - Hydrometer or Refractometer?

 

[kaiserben]

Oh sorry - hydrometer.

Checked it last night in tap water and it's bang on.

EDIT: and all samples measured at ambient temperature of ~20C.

 

[kaiserben]

And in amongst those brews I had 2 others, another session IPA and a 6.3% American Amber, almost exactly right on OG and FG.

 

[danestead]

If you aren't measuring gravity's until you've bottled them, how do you even know they are finished fermenting?

I'm sure you will change your habits now and it doesn't need to be said, but seriously, it's really dangerous bottling home brew without checking that the beer has finished fermenting fully. There are people who have ended up in emergency with cuts due to exploding glass stubbies. Even if you bottle in plastic, if those beer haven't finished fermenting when you bottle them, they are going to gush everywhere when you open them and there's going to be no beer left in the bottle to drink.

If they are in fact stuck ferments, I can't really help you with a solution sorry.

Edit: Actually, how are you storing your dry yeasts?

 

[contrarian]

I've had a few ferments stall with S-04. Often a gentle swirl of the fermenter and if possible raising the temperature a few degrees can get things moving again. If you have a beer that you are sure is stuck and won't budge with gentle methods you can try mixing about 50g of sugar or DME with 1-200mL of boiling water and adding this to the fermenter, sometimes giving the yeast some simple to chomp on can get things going again.

Some ferments take longer than others depending on a variety of factors, I've made saisons that took 4 or more weeks to fully ferment out. Normally you want to see 3 days of the same gravity and in the ball park of what you were expecting before bottling to be on the safe side.

Have you had any issues with the bottles of these beers being gushers? If you haven't cracked any yet make sure you are careful when you do. As said above, bottle bombs can lead to serious injury.

 

[kaiserben]

With that 2nd example (Pale Ale that finished 1.024 instead of 1.014), I left bottles at ambient for 2 days before putting in fridge (thinking that this would slow the carbonation to the point where it was no longer dangerous). They tasted great with no gushing, and the carbonation was about where I would've wanted it anyway.

With the 4th example I bottled last night and I'm a bit more worried about them. I would have liked to leave for 2 days then whack them in fridge, but 1.030 instead of 1.011 ... might put them in fridge tonight (so 24 hours at room temp).

EDIT: And some in PET some in glass, so I might pop the glass ones and drink as much of them as I can tonight

 

[danestead]

Am I correct in saying that you are new to brewing? If so, and I'm not trying to be mean but you need to read through the basics of brewing beer and start off with kits or the like because leaving your beers for only 2 days after bottling and then putting them in the fridge to drink is way off the mark. To allow your beers to bottle carbonate you need to be adding some sugar to the bottles then leaving at ambient temperature (about 20 degrees) for about 3 weeks before you think about drinking them.

You need to get the fundamentals down first so I suggest you have a read of this http://aussiehomebrewer.com/topic/9233-frequently-asked-questions-for-the-new-brewer/ as a starter and go from there.

Good luck with it and hopefully you are drinking nice beers soon.

 

[yum beer]

If your ferment isn't finished the bottles will still ferment even at fridge temps, it will take longer but bottom line, if they weren't finished, they will go KABOOM.
Hopefully not when you are holding one, or admiring it from up close, or standing in front of the open fridge, child walking by........
Until you clean up the mess from a bomb you don't fully get the mess and danger involved.

I can't see that there is any other issue here, hydro good in tap water, some brews been in the range, look at yeast health and handling and/or get some way of measuring your temps more accurately, if your fermenting box is 5-6 degrees below what you think, then you aren't finishing off the ferment.

 

[Dae Tripper]

Tell us more about your ferment temps, length of time in fermenting, what in etc. It is possible you can't see the forest for the trees somewhere.

On my ales I like to raise the temp about 3 degrees for the last few days to make sure the yeast cleans everything up.

 

[verysupple]

Where are you located? If you're down south in the cold weather I'm agreeing with yum beer and think it might be the fermentation temp dropping toward the end. An insulated chamber helps, but it's not going to stop the beer temp dropping once the most active part of fermentation has finished.

 

[kaiserben]

Am I correct in saying that you are new to brewing? If so, and I'm not trying to be mean but you need to read through the basics of brewing beer and start off with kits or the like because leaving your beers for only 2 days after bottling and then putting them in the fridge to drink is way off the mark. To allow your beers to bottle carbonate you need to be adding some sugar to the bottles then leaving at ambient temperature (about 20 degrees) for about 3 weeks before you think about drinking them.

You need to get the fundamentals down first so I suggest you have a read of this http://aussiehomebrewer.com/topic/9233-frequently-asked-questions-for-the-new-brewer/ as a starter and go from there.

Good luck with it and hopefully you are drinking nice beers soon.

Nope. I either didn't explain it well enough or you didn't read my posts properly (admittedly that first one was incredibly long ...)

The only beer I've put in the fridge after 2 days was a Pale Ale that was bottled at 1.024 (instead of predicted 1.014) after 12 days in fermenter at fairly constant 20C. And the ONLY reason I put them in the fridge was because I was freaking out about potential bottle bombs and thought the cooler temp would slow and virtually stop any further carbonation.

I'm now considering doing the same thing to another batch, this time an IPA, that was bottled at 1.030 (instead of predicted 1.011) after 14 days in primary and 3 further days in secondary. But it sounds like it's maybe too dangerous to attempt and that I should ditch the batch (after drinking as much uncarbonated beer as I can )

 

[kaiserben]

Tell us more about your ferment temps, length of time in fermenting, what in etc. It is possible you can't see the forest for the trees somewhere.

On my ales I like to raise the temp about 3 degrees for the last few days to make sure the yeast cleans everything up.

I have a stainless steel fermenter that goes inside the chamber. It's always steady air temp of 20C in that chamber. That temp will climb a few degrees during the main fermentation stage, but then drop back to 20C again.

Nearly all ferments are 12 days in primary.

I don't have any temperature control (yet) for my chamber.

 

[jimmy_jangles]

how do you know that they are at 20c if you don't have a temp control?

 

[kaiserben]

steady air temp of 20C in that chamber. That temp will climb a few degrees during the main fermentation stage

Of course, I don't know the exact wort temp. But I do know the air temp, using a thermometer.

 

[Judanero]

Maybe shell out the $20 or so and grab a stc, even if it's not actively cooling or heating once calibrated and taped (and insulated) against the wall of the fv you'll get a better idea on temps.

Have you calibrated your thermometer in ice slush for zero and boiling for ~100c (depending on elevation)?

Have you checked your air temp early in the morning, say 0500? Could be the wort is a few degrees cooler than air temp.

Could try leaving in fv a bit longer, maybe it is still dropping points just a lot slower... It sounds like your yeast has dropped out at some point as others have said.

Could also be oxygen supply to the yeast, are you aerating/shaking/oxygenating?

There's a few things it could be, if you want to isolate the problem just change things one at a time to narrow it down.



God speed.

 

[Rocker1986]

If your ferment isn't finished the bottles will still ferment even at fridge temps, it will take longer but bottom line, if they weren't finished, they will go KABOOM.

How will they still ferment if they are sitting well below the yeast's fermentation range and it has gone dormant? :unsure: I only say this, because I had a couple of batches of ale a couple of years ago that refused to carbonate once they got too cold (and that wasn't even as low as a fridge). There was a tiny bit from while they were still warm enough but once they dropped that was it, they never carbed any further, ever.

Not that I'm at all saying it's a good practice to bottle beer that hasn't finished fermenting, however I would have thought sending the yeast to sleep would stop the things from exploding?

 

[kaiserben]

I've done a lot of reading on this subject recently ...

I think my main problem was my starting gravities were usually on or past the higher end of the scale for 1 packet of yeast and, because I wasn't rehydrating, a portion of yeast cells were being killed by pitching direct, which made my pitching rate lower than it perhaps should be.

And combined with that my oxygen levels were possibly under what would be ideal (particular for beers where gravity is getting up there).

Could also be oxygen supply to the yeast, are you aerating/shaking/oxygenating?

I reckon this is a likely contributor to the problem. My process was simply pumping the wort from kettle to FV and letting it fall from the hose about a metre to let it splash. That would cause a few centimetres of foam to form above the wort (which from what I've read is an indicator that you're getting oxygen in the wort, but maybe not enough). I'd then check wort temp and sprinkle the yeast. Leave for half an hour. Give it a (very quick) shake. Then put it in a chamber.

So from now on I'll rehydrate every time. I'll also pay closer attention to pitch rates (possibly use 1.5 or even 2 packets depending on the beer). And I'm going to invest in wort aeration (using pure oxygen and diffusion stone). Oh ... and I'll check my gravity before bottling h34r:

 

[yum beer]

yum beer, on 30 Jul 2015 - 5:59 PM, said:

If your ferment isn't finished the bottles will still ferment even at fridge temps, it will take longer but bottom line, if they weren't finished, they will go KABOOM.

Rocker 1986
How will they still ferment if they are sitting well below the yeast's fermentation range and it has gone dormant? :unsure: I only say this, because I had a couple of batches of ale a couple of years ago that refused to carbonate once they got too cold (and that wasn't even as low as a fridge). There was a tiny bit from while they were still warm enough but once they dropped that was it, they never carbed any further, ever.

Not that I'm at all saying it's a good practice to bottle beer that hasn't finished fermenting, however I would have thought sending the yeast to sleep would stop the things from exploding?



Yum beer
I have had this happen with 2 batches, neither got to the point of KABOOM, but both slowly continued to get higher carbed the longer they sat.
1 batch I think I just rushed to get into the FV and the other was a dry lager with enzyme. Both into fridge at 2c after 2 weeks carbing at ambient, both with normal carb, over the following weeks the bottles got gasier and gasier as they went, to the point I was fairly worried when popping them open. Yeast will sleep when the temps drop, but just like people, some yeast eat in their sleep, especially if there is a food source around. There is a reason that the big boys filter and pasteurise, get rid of or kill to be sure.
If you are bottling above expected FG I have no doubt you will have a bad end result given time.

 

[danestead]

A lack of yeast shouldn't really affect the FG on a standard strength beer. Maybe when you start pushing the yeast alc tolerance (generally 9%ish and up). It will throw undesirable fermentation characteristics though, which is why pitch rate is so important.

If you want to see if your beer is actually at its proper FG, take 1 of your bottles and do a forced or fast ferment test. Google those terms for the process.