You might be waiting a long time with that philosophy. A gravity reading is the only way to know what’s really going on.
Could not agree more. Even with the temperature constant, the fermenter will continue to off-gas CO2 for weeks after fermentation is finished.
Well, my fermenters don’t. Not saying that you and Denny are wrong necessarily. Bubbles mean that pressure is building in the fermenter headspace, either from an increase in temperature, or from something outgassing from the wort, which could mean fermentation.
After a couple of weeks, my airlocks are dead quiet, so that’s when I package. I don’t test my gravity during fermentation, only after I think it’s over. That’s just because I’m lazy and I don’t like to open my fermenter to take gravity tests. In fact, this may be why your fermenters continue to bubble, with each test you are letting out CO2 and letting in room air, decreasing the concentration of CO2 in the headspace. I could see where that would lead to CO2 coming out of solution in the wort over time and making bubbles in the airlock even after fermentation is complete. I doubt that would happen otherwise as the partial pressures of CO2 in and out of solution should equilibrate during fermentation.
If you’re going to kegs, none of this matters anyway as you can easily adjust the pressure in the keg if there is a problem. But I don’t recommend going to bottles, especially in the presence of increasing airlock activity, assuming that the temp isn’t rising. Bubbles in the airlock means that the pressure would rise in a sealed container, regardless of the source of the bubbles. One bubble every 30 seconds may not be a big deal, but there’s no way to adjust the pressure after bottling. As always, you should use the methods that best suit your process and your beer.
[quote]After a couple of weeks, my airlocks are dead quiet,…
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So are mine. Bubbles are a great gauge for telling you when it’s time to take another gravity reading. I also agree that presence CO2 bubbles doesn’t just happen without a reason. It’s either due to fermentation, temperature change, dry hopping or simply moving the fermenter, but whatever the case, it will eventually stop.
It could mean fermentation, but I don’t believe it necessarily does. Once fermentation is finished, the beer is super-saturated with CO2. The partial pressure of gases in solution will exponentially decay as it approaches the atmospheric pressure, but if I had to guess I’d say the time constant is on the order of several days - based on the fact that I continue to see the occasional bubble for weeks.
In fact, I see the same thing at work where we’re pulling from a sample port and therefore decreasing the pressure in the fermenter headspace. The blowoff buckets continue to bubble every once in a while for the entire warm maturation period. Granted, that’s typically less than a week, since I tend to let things sit longer at home.
THIS^^^^
WHAT?!^^^^ ;D
I hear you guys. Just discussing here, but… Freshly fermented beer is supersaturated with CO2. But it is also underneath an atmosphere with a high CO2 concentration. Even if it wasn’t, how long does it take for an open beer, or a soda, to go flat? That’s just a release of supersaturated CO2, and from a much higher dissolved concentration than in a fermenter that has a mechanism for releasing pressure.
Sean, if you’re decreasing the pressure in the fermenter headspace by pulling from a sample port, then it sounds like you’re not using any type of liquid airlock? Or are you getting suck back (even if it is not enough to actually pull airlock liquid back into your fermenter)? And it sounds like you’re bringing the temperature up for warm maturation? That would result in bubbles.
Just my experience on a homebrew scale, I’ve never fermented in a container larger than 7.5 gallons where maybe things are different.
THAT ^^^^
Maybe 2-3 days, without an airlock?
We do use a liquid airlock, a tube from the top TC port to a bucket of sani on the floor. There would have to be a pretty significant decrease in pressure for any sani to get in the fermenter.
We do bring the temperature up, on roughly the third day of fermentation. After that it stays at 72±1°F for a week or so before we cold crash it. Typically our ales will reach FG on day 5-6 (verified by daily hydrometer readings) but continue to off-gas until we crash them on about day 12.
There is a really simple experiment you could do next time. A week or two after active fermentation is finished, agitate the fermenter. I’d bet money on you seeing a burst of airlock activity, indicating that the CO2 in solution hasn’t come to equilibrium.
Well, hmmmmm.
I made the decision to go ahead and bottle on Sunday (25 second bubbles). Whatever the reason for the action, I’m hoping I do not end up with a situation like my last batch of AG - increasing eruptions upon opening. The final bottle I opened left me with exactly 3 ounces of liquid. However it was good.
As for this batch, I did sample at bottle time and it was really, really good. Detected no off flavors at all. As for temperature, I use a wine cooler for storage and is consistently 68 degrees F. At 1.011 “FG”, it was clearly done fermenting. Being worried about the bubble rate, I used only a half cup of priming sugar. After 3 days now, no bottle rockets yet.
If “intense gushing” means I have an infection (and same with previous batch), I’ve a mind to just give up on the AG brewing and go back to (gasp!) extracts. I am VERY careful of sanitation when I brew - nothing else I can think to do. Of this is “off gas CO2”, then I do not know the reason, but I’m tired of wasting 2/3 of my brew just because I open the bottles. Yes, perhaps I should go to kegging, but I have space issues.
I guess it would have eventually stopped bubbling and then maybe I would not be risking the high volatility of the final product. But I had to make a decision to go and I did. If there would have been a noticeable decline in bubble rate, I would have waited, but it was increasing - as unlikely as that seems.
BTW, as far as airlock (trying to answer everyone’s questions), I destroyed mine when I racked to secondary, so I was just using a blowoff tube run into a pitcher of water. I don’t see how I could have been getting “suck back” there.
Maybe AG brewing is not for me - yeah, I’m getting depressed. lol
Thanks all.
Don
+1 to this advice. Its possible that your extended bubbling is from a fermentation that was interrupted and was/is struggling to finish.
How could AG vs Extract really affect this? The differences between to two are almost all before the boil whereas infections usually come from something post-boil. Post-boil, the processes/equipment/etc for AG and Extract are pretty much identical.
That’s true, Hokerer. I’m just frustrated - I’ve not had this kind of issue before and it seemed to come with AG, but that should not matter, I understand.
Will do, my mash depth experiments are happily burbling away. A little too happily - it has inadvertantly become a blow-off v. no blow-off side by side batch, too. :) But it will be perfect for this.
An update. After 10 days, had a few bottles of the beer.
It is wonderful. Thanks to everyone who has helped.
One question: at bottling time, the sampling I took was crystal clear. Was amazing. The first bottle I drank, the clarity
was just as good. The second bottle was very hazy (yes, I poured them both correctly). Looking through the rest of the
bottles, it seems that there is the gamut - from very hazy to extremely clear. Most have some sediment floating around in
them - even the very clear ones.
I was careful to mix my priming sugar in well before bottling - trying to take care not to aerate, to the best of my ability.
Any suggestions as to what happened here?
Thanks.
Don
dons,
on the AG v Extract and infection front, do you grind your own grain? if so do you do it in an area that might allow a small amount of grain dust to then settle in a way that would potentially get in your finished wort or beer? grain is a great carrier of infectious microbiota.
additionally the difference between extract and AG in terms of gushing could have to do with mash temps producing a more fermentable wort than expected. whereas with an extract recipe you can pretty easily say that and OG of x will result in an FG of y as the fermentability is fairly constant. while with AG a couple of degrees difference in mash temp could produce significantly different expected FGs. just a thought.
My guess would be that after 10 days they haven’t all fully carbonated, and some still have yeast in suspension. Give it another week and they’ll probably start to settle out.
The kreusen on the no blow-off batch finally dropped on Monday, though airlock activity has been dead for a while. I shook the crap out of it today, enough to get it to foam. No airlock bubbles after shaking it. The airlock has been in place since I pitched, so I would imagine that the CO2 levels inside the fermenter headspace are quite high. On the other hand, the blow-off batch blew the water out of its airlock and was exposed to the air for 12-24 hours. It was exposed again when I removed the blow-off tube that I hastily fitted and replaced it with an airlock. The water in that airlock is still under pressure and I’m quite sure that if I shook that batch, the airlock would bubble.
So I stand by my highly scientific experiment and my thoughts about CO2 stated in this thread. 