Fermenting a 9%

[matt23]

So I put in a beer that's supposed to be about a 9% into the fermenter two weeks ago, was bubbling like crazy the first few days, as normally done, from which it moved to a steady bubbling rate, once every 1-2 seconds and has been like this for the last 10 days. The ABV is about where it's supposed to be and has been steady for more than a few days. To get the ABV over 7%, I added a bunch of the dark Belgian candi sugar, looked and tasted like brown sugar.

Question being, is this normal for a stronger beer loaded with extra sugar? Thinking with the different sugars involved, there lots more for the yeast to work with, not just for ABV but other byproducts that the yeast is working on cleaning up. Do you think it'd be ok to go ahead and keg it, for storing/aging for another two weeks?

I've had a similar issue with a wheat beer I did in the past where it kept on bubbling weeks after it started fermenting, but this was only bubbling once a minute or so, not every 1-2 seconds as is happening now.

Thanks for any insight.

 

[gometz]

If I understood you correctly, you added the syrup and it started bubbling again? That's normal. As is a steady bubble when you have that much fermentable sugar in a wort. I hope you pitched enough healthy yeast for that strength, otherwise it will be very thick.

Additionally, bubbling can come from more than just CO2 generation during fermentation. Temperature rises can cause CO2 to come out of solution, if the beer is super saturated in CO2 just moving it can cause it to bubble, etc.

 

[matt23]

The sugar was added to the boil, before it went into the fermenter.

With it still bubbling so much, every second still seems a bit much, do you think I should wait to keg until it slows down or probably good to go as is, as it's been two weeks and the ABV has pretty much plateaued.

I guess another concern with the activity is what will it do once kegged, i.e. will the bubbling caused too much pressure, explosions, etc? It's obviously still doing something but I don't know how critical. I guess I could wait another week to see what happens, if it slows down more or not, but would prefer to age the rest of the process in kegs, get a new batch in the fermenter started.

 

[jmcquesten]

So I put in a beer that's supposed to be about a 9% into the fermenter two weeks ago, was bubbling like crazy the first few days, as normally done, from which it moved to a steady bubbling rate, once every 1-2 seconds and has been like this for the last 10 days. The ABV is about where it's supposed to be and has been steady for more than a few days. To get the ABV over 7%, I added a bunch of the dark Belgian candi sugar, looked and tasted like brown sugar.

Question being, is this normal for a stronger beer loaded with extra sugar? Thinking with the different sugars involved, there lots more for the yeast to work with, not just for ABV but other byproducts that the yeast is working on cleaning up. Do you think it'd be ok to go ahead and keg it, for storing/aging for another two weeks?

I've had a similar issue with a wheat beer I did in the past where it kept on bubbling weeks after it started fermenting, but this was only bubbling once a minute or so, not every 1-2 seconds as is happening now.

Thanks for any insight.

It's probably a good idea to give it 3 - 4 weeks in primary just in case the yeast is still slowly working. But, since you're kegging it you could do it if you're in a hurry. I don't know if I would expect the beer to be awesome after 2 weeks in the keg though, regardless of how long it's in primary.

Now if the question was "can I BOTTLE it?", the answer would be "not yet". Bottles could explode.

 

[matt23]

It's probably a good idea to give it 3 - 4 weeks in primary just in case the yeast is still slowly working. But, since you're kegging it you could do it if you're in a hurry. I don't know if I would expect the beer to be awesome after 2 weeks in the keg though, regardless of how long it's in primary.

Now if the question was "can I BOTTLE it?", the answer would be "not yet". Bottles could explode.

Yeah, makes sense, thanks, I'll leave it in for another week, hopefully it'll slow down more by then. This is the first ~9% I've done, first with all the candi sugar, so on a new learning curve...

 

[flars]

Check the specific gravity in a week. Check the gravity again a few days later. A stable SG over a few days will indicate the fermentation is done most of the time. Sometimes the gravity will slowly drop over the period of another week with some yeasts.

Taste your SG samples and check the amount of sediment in the samples. You may want to give the beer more time in the primary is there is a lot of suspended excess yeast and other sediment.

 

[Kharnynb]

depends a lot on yeast amount and type, but with sugary beers, they will eat through the simple sugars...FAST. then they slowly finish all the other food that is there and a lot of byproducts from the fast fermentation.

 

[d3track]

What temp and what yeast strain? Might be good to give it a temp bump to finish out. With big beers like that, patience is key.

 

[matt23]

What temp and what yeast strain? Might be good to give it a temp bump to finish out. With big beers like that, patience is key.

The current temp is 80 F, yeast used is Safbrew T-58.

The temp is warmer than normal, I think still recovering from the initial fermentation over the first few days. It started at ~75, but after the first day, the reactions were so intense it overflowed up and down the CO2 relief hose, overflowed the water bucket, and cranked up to almost 100 F from all the activity.

 

[Kharnynb]

ouch....should have had a swampcooler or some similar cooling for that, you might get massive off-flavours with that kind of heat...

 

[matt23]

ouch....should have had a swampcooler or some similar cooling for that, you might get massive off-flavours with that kind of heat...

yeah, starting off at ~65-70 would have been better, but then again, not sure how you'd get around that to some extent. I mean, the amount of sugars provides for much more intense reactions. Starting off at 75 may be a little high but not too much, and definitely within the range of the yeast capabilities. Other less ABV beers maybe increase it 10-15 degrees during initial fermentation, I didn't expect it to be +25. Even starting at 65 would put it at 90 for a few days.

Another question or something to consider, if you artificially cool the beer while it's doing its thing, does that negatively impact the result, sort of interrupt the natural process of the yeast? The Belgians have been making this stuff for centuries and I don't think they artificially cooled it while in process.

It'll be different no doubt. It also includes a bunch of other ingredients, such as star anise, coriander, cardamom, grains of paradise, rose hips, and some irish moss. It's actually been smelling pretty decent as I've been testing it, will be giving it an initial taste testing over the next few days. Should be interesting to see how it changes with age. Starting to think this might be one to age a few months even.

 

[Kharnynb]

They cool by having massive stone cellars.....
Generally putting your fermenter in a big tub with around 5 gallons water to give it somewhere to heat dump helps a lot.
I use a concrete mixing tub from DIY store, they cost less than a tenner.

 

[gometz]

If you started at 75*F and made it to 100*F, that will likely lead to some off flavors, hot alcohol flavors at the very least (looks like T-58 has a temperature range of 54-77, ideally 59-68*F). Even saison yeasts get a bit unhappy reaching 100*F during fermentation.

Another factor is if you didn't use a starter, had a high OG (with simple sugars), and high temperature, you likely stressed the crap out of the yeast. It could be still bubbling because the yeast crapped out and is limping along. I'd take a sample and check the gravity.

For future reference on controlling the temperature during fermentation:
Controlling the external temperature will most definitely minimize swings. If you can use a refrigerator with temperature control, you could probably limit the difference in a 5-6 gallon carboy to 3-4*F. This is essentially what Khanynb is referring to how temperature was controlled before the invention of refrigeration (big cool cellars that stayed a steady temperature year round). Your beer is only able to get such a large temperature swing because the ambient air is somewhere close to that, plus if you cover it or enclose it somehow (how are you coming up with the 100*F? in fact how are you coming up with the 10-15 degree rise for a "normal" beer?). Maintaining temperature control is very important, some beer styles can be a bit more forgiving, but it is critical especially in early fermentation when the yeast is doing most of its reproducing.

Another method to minimize temperature spikes, and potentially keep your yeast healthier, is to add the sugar/syrup after the initial fermentation is complete. This way the energy of the fermentation is split between two fermentations instead of all at once. If the sugars are added during the boil, the yeast will go for it first. I've heard/read theories that once yeast begins to consume sucrose it can become less adept at consuming maltose. Not sure how true that is, but could have some validity.

From a historical perspective:
Depending on what you are calling "artificial cooling", they most definitely did. Again those big cool cellars. The German Reinheitsgebot I believe had a provision that you couldn't brew from April to September, this came from the fact that they noticed beer started in those warmer months was lower quality (and again I believe it was also to get more people working in the fields instead of brewing beer). Unless you are hard crashing the temperature, a lower ambient temperature just acts as a larger heat sink, so the yeast stays in its happy range.

 

[Kharnynb]

as @gometz says, it really matters, using room temperature water instead of air already helps as water is much better at taking the heat, plus you can add frozen water bottles if needed.