[Will's Swill]

I do the same thing without the padding.  That is, I have a bucket in bucket lauter tun and fly sparge.  I put the whole thing in an insulated box so that I can use it as a mash tun as well, avoiding the need to transfer between mash tun and lauter tun.

[dons]

Nothing to do with hops, but still on the beer I mentioned here.

I brewed on April 30.  Racked to secondary on May 5.  Today is 3 weeks and 2 days
since racking (nearly a month since brewing).  I know, I'm told not to trust bubble rate
but note the following.  2 weeks ago the bubble rate was 70 seconds.   1 week ago
the bubble rate was 50 seconds.  Today, the bubble rate is 30 seconds.  

This is just making no sense to me.  I did make a seemingly very good starter, but should
this not have calmed down by now?

This morning, I took a sample and the hydrometer reading is 1.011.  I KNOW that, according
to this, the beer is ready to bottle.  However, with that bubble rate I'm afraid of blowing up
bottles (been there, done that).  By the way  Hamiltont's estimate of OG and FG was just
spot on (where do I find a calculator like that??).  

So, what should I do?  Drinking the beer, it seems like probably my best to date and I'm
anxious to get this done (also need the space for another batch).

You guys have been SO helpful, thought I'd make this plea.

Don

[tschmidlin]

You've answered your own question.

I know, I'm told not to trust bubble rate

It could be bubbling for a number of reasons, including temperature fluctuations.  Bottle it.

Next time, don't rack to secondary until the beer is finished, then rack to a bottling bucket and bottle it.  It's been 4 weeks, if you'd left it in primary you probably could have bottled it 2 weeks ago.

[thomasbarnes]

Have you been tasting the samples you've drawn off for gravity readings? If you're getting off-flavors, it could be a sign that you've got an incipient infection (probably wild yeast or lactobacillus).

In either case, the increase in bubbling might be a sign that one of the bad bugs gobbling up the dextrins in your beer.

In any case, bottle it, let it condition for a week and taste it again. A long, slow, but intense gushing means that you've got an infection (unless you overprimed or bottled before you hit your FG). A crisp, yogurt-like sour which you can only detect in flavor means lactobacillus infection, while smoky, medicinal or clove-like aromas and flavors means wild yeast.

If you're worried about bottle bombs, put your bottles in a covered plastic storage bin - the lid and sides will catch any shrapnel, the bottom will catch any spills. Alternately, put the bottles in a sacrificial cardboard box on a surface you can easily clean and sanitize like a basement or garage floor. If you do get a bottle explosion, just remember to not pick up the soggy cardboard box!

If you do get bottle bombs, try to chill the remaining bottles to as close to freezing as you can get. Then carefully uncap them while wearing leather gloves, a long-sleeved shirt and safety goggles.

[Will's Swill]

I tend to trust the bubbles more than others.  Unless you're sure they're from temperature fluctuations, I'd wait ot bottle to avoid bottle bombs.

Edit: And if you're going to go the cardboard box route, seal the box.  I had a bottle bomb go off in one that was just closed, but not sealed.  I had beer on the ceiling...

[denny]

Me, I tend to trust the bubbles more than others.  Unless you're sure they're from temperature fluctuations, I'd wait ot bottle to avoid bottle bombs.

You might be waiting a long time with that philosophy.  A gravity reading is the only way to know what's really going on.

[a10t2]

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.

[Will's Swill]

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.

[ccarlson]

After a couple of weeks, my airlocks are dead quiet,... 

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.

[a10t2]

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.

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.

[denny]

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.

THIS^^^^

[Will's Swill]

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.

THIS^^^^

WHAT?!^^^^   

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.

[ccarlson]

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.

THIS^^^^

WHAT?!^^^^   

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 ^^^^

[a10t2]

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.

Maybe 2-3 days, without an airlock?

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.

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.

Just my experience on a homebrew scale, I've never fermented in a container larger than 7.5 gallons where maybe things are different.

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.

[dons]

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