FG stable but airlock still bubbling

[Brauhaus Fritz]

Maybe the question has been raised before, but what to do if the gravity is stable over a few days but the airlock is still bubbling once in a while?

To bottle or not to bottle, that is here the question?

[Classic Brewing Co]

2 minutes ago, Brauhaus Fritz said:

Maybe the question has been raised before, but what to do if the gravity is stable over a few days but the airlock is still bubbling once in a while?

To bottle or not to bottle, that is here the question?

It probably would depend on how long it has been in the FV but it could very well be done however the airlock shouldn't still be bubbling. As you say if the FG has been stable you should be safe to bottle.

[Otto Von Blotto]

I'd trust the SG reading more than an airlock. Could just be minor temperature changes causing it to bubble

[Aussiekraut]

2 hours ago, Brauhaus Fritz said:

Maybe the question has been raised before, but what to do if the gravity is stable over a few days but the airlock is still bubbling once in a while?

To bottle or not to bottle, that is here the question?

Taste it and if it is fine, bottle it. The hydrometer is the ultimate authority. That’s why a fair few of us do not use airlocks anymore. 

[Classic Brewing Co]

Just now, Aussiekraut said:

Taste it and if it is fine, bottle it. The hydrometer is the ultimate authority. That’s why a fair few of us do not use airlocks anymore. 

I agree with you & Otto, the hydrometer is the only way to know what is going on. 

[Shamus O'Sean]

5 hours ago, Brauhaus Fritz said:

Maybe the question has been raised before, but what to do if the gravity is stable over a few days but the airlock is still bubbling once in a while?

To bottle or not to bottle, that is here the question?

I have noticed this phenomenon since doing some pressure fermenting.  SG is stable (and has been for a day or two) but still some bubbles coming out of my blow-off tube.  It could be subtle temperature changes as others have suggested.

Also, as all have said, trust the hydrometer.  I usually wait for three stable SG readings before cold crashing for up to a week before bottling or kegging.

[iBooz2]

6 hours ago, Otto Von Blotto said:

I'd trust the SG reading more than an airlock. Could just be minor temperature changes causing it to bubble

More likely to be caused by the ambient air pressure in your area changing from a dominant high to a low at that time.  Going from a general high of say 1030 mpa down to 1000 mpa will cause it (for example), just look at your local weather chart. 

If you were to lift your FV up in the air by 30 ft at any time it would experience a 1 mpa drop in outside pressure so a 30 mpa drop as in above weather example would mean an equivalent of lifting your FV 900 ft up in the air.  Of course is is going to burp more bubbles that is why parachutist's fart like hell and uncontrollably when they get taken up to 10,000 ft before they jump and its not because they are nervous.  @Classic Brewing Co , just ask your A380 pilot mate to explain to you "Area QNH". 

Plenty of pilots have flown themselves and their planes into mountains because they forgot to adjust or incorrectly adjusted to the local area QNH on their aircraft altimeters.   There is a memorial near the top of Mt Dandenong here in Melbourne because of that exact phenomenon.

Edited February 4, 2022 by iBooz2

[kmar92]

42 minutes ago, iBooz2 said:

Of course is is going to burp more bubbles that is why parachutist's fart like hell and uncontrollably when they get taken up to 10,000 ft before they jump and its not because they are nervous.

Well I never knew that!!!

[Brauhaus Fritz]

Thank you guys for your help, I think I will have to adjust my template to keep notes to get to the bottom of a possible connection of volcanic eruptions when opening bottles, same cracked bottles.....  So far I waited extra days ( up to a week) with bottling, but then I had some bottles exploding and some foamy eruptions, loosing the whole bottle content  (could have been over carbonation, as I used two drops for 640ml bottles?! or dirty old cracked bottles I've been given?!) It's not whole batches, just a bottle here and there. Just like to get to the bottom of it

[Classic Brewing Co]

2 hours ago, Brauhaus Fritz said:

Thank you guys for your help, I think I will have to adjust my template to keep notes to get to the bottom of a possible connection of volcanic eruptions when opening bottles, same cracked bottles.....  So far I waited extra days ( up to a week) with bottling, but then I had some bottles exploding and some foamy eruptions, loosing the whole bottle content  (could have been over carbonation, as I used two drops for 640ml bottles?! or dirty old cracked bottles I've been given?!) It's not whole batches, just a bottle here and there. Just like to get to the bottom of it

The closest I have come to a bottle exploding was opening a Grolsch bottle 450ml & I use 1 x full sugar scoop (6gms) of sugar when the swing top blew off the bottle & chipped it.

I use 1 x full scoop in all of my bottles 450/500/740/750 mls & by drinking the smaller ones first it works out, occasionally 6 gms is too much for a 450ml bottle.

By the time I get to the 740/750ml bottles they are carbed up nicely.

[ozdevil]

The airlock activity is most likely off gassing and not actually fermentation.

The off gassing is caused by the prior fermentation process. As the beer is fermenting, it is creating Alcohol and CO2. Most of the CO@ goes out through the airlock, but some off it gets locked up in the trub,yeast and hops. The Co2that is locked up will slowly degas out through the airlock, eventually leading to a still beer (Still beer is beer with absolutely no carbonation)

So as others have said, hydrometer is your best friend to when fermentation process is done   2 readings the same bottle it

The airlock is not the great measure of fermenting as the airlock is basically just allowing the bad gases to esacape

 

[Brauhaus Fritz]

2 hours ago, Classic Brewing Co said:

The closest I have come to a bottle exploding was opening a Grolsch bottle 450ml & I use 1 x full sugar scoop (6gms) of sugar when the swing top blew off the bottle & chipped it.

I use 1 x full scoop in all of my bottles 450/500/740/750 mls & by drinking the smaller ones first it works out, occasionally 6 gms is too much for a 450ml bottle.

By the time I get to the 740/750ml bottles they are carbed up nicely.

I had a few bottle where literally the bottom fell off. I picked them up and the bottom stayed in the crate like it was cut off. And where the liquid went? No Idea.

6 grams is that 1 1/2 drops?  The last two batches I bottled I used 1 drop for 500ml bottles. 64Oml bottles I have not refilled yet, but will try 1 drop only as well. It's all about experimenting and experiencing, isn't it?

[Classic Brewing Co]

33 minutes ago, Brauhaus Fritz said:

I had a few bottle where literally the bottom fell off. I picked them up and the bottom stayed in the crate like it was cut off. And where the liquid went? No Idea.

6 grams is that 1 1/2 drops?  The last two batches I bottled I used 1 drop for 500ml bottles. 64Oml bottles I have not refilled yet, but will try 1 drop only as well. It's all about experimenting and experiencing, isn't it?

Lose the carb drops, use plain white sugar, it is easy to measure out with a sugar scoop, there are various styles available, below is 1 x teaspoon of sugar, the big end on the sugar scoop measures out 6 grams. I get a much better result & it is cheaper, even tastes better.

It's not about the cost but over the years I have had disappointing results with the drops, even some of our most seasoned members have stated they used sugar when they bottled.

I always get a nice head using sugar for carbonation. Anyway that is my opinion. Cheers.

[Space]

My method now is to wait until I have two days of similar hydrometer readings, then I leave it for a couple more days anyway.   It just seems to be a bit clearer and a bit more consistant bottle to bottle.

[Brauhaus Fritz]

Patience seems to be the way

[iBooz2]

@Brauhaus Fritz , you did not say what the stable gravity was.  If it was 1.020 and stable for a couple of days then maybe a stalled brew and bottling would be disastrous.   If it was 1.012 (for example, just picking a number here) yes probably at final gravity so yes leave it for a few more days then bottle it. 

Do you raise the temp of your brews as they near final gravity to ensure they are all done and dusted which gives the yeast time at enough warmer temperatures to clean up?  What's called a D-Rest in the lager world and not really necessary in the ale world but it does help finish off the ferment of better.

[Brauhaus Fritz]

2 minutes ago, iBooz2 said:

@Brauhaus Fritz , you did not say what the stable gravity was.  If it was 1.020 and stable for a couple of days then maybe a stalled brew and bottling would be disastrous.   If it was 1.012 (for example, just picking a number here) yes probably at final gravity so yes leave it for a few more days then bottle it. 

Do you raise the temp of your brews as they near final gravity to ensure they are all done and dusted which gives the yeast time at enough warmer temperatures to clean up?  What's called a D-Rest in the lager world and not really necessary in the ale world but it does help finish off the ferment of better.

Yeah , the gravity is low, in range of the projected FG

[iBooz2]

8 hours ago, Classic Brewing Co said:

I always get a nice head using sugar for carbonation. Anyway that is my opinion. Cheers.

@Classic Brewing Co, have you tried adding a measure of dextrose to your bottles instead of white sugar?  Years ago I used sometimes dextrose and then sometimes white sugar.  I note that @Greenyinthewestofsydney seems to recommend dextrose if you want a more tightly packed foamy white head on your beer.  Be interesting to see a side by side with the same batch of beer and same sized bottles.  I cannot remember which one was better back in the day, too many beers ago.

[Classic Brewing Co]

9 minutes ago, iBooz2 said:

@Classic Brewing Co, have you tried adding a measure of dextrose to your bottles instead of white sugar?  Years ago I used sometimes dextrose and then sometimes white sugar.  I note that @Greenyinthewestofsydney seems to recommend dextrose if you want a more tightly packed foamy white head on your beer.  Be interesting to see a side by side with the same batch of beer and same sized bottles.  I cannot remember which one was better back in the day, too many beers ago.

@iBooz2 Al, No I haven't but that is interesting as I was online reading about it & some swear that it is better than sugar but I was worried it would water/weaken your beer. If you are recommending it I will try a few bottles with my next batch & see what happens, I will catalogue everything & post the  results. Cheers for that.

Edited February 5, 2022 by Classic Brewing Co