Damn Carbonation won't happen

[PerryS]

Well, I'm waving the white flag on this batch - it is what it is - lame carbonation after a month + in 70+ degree room.

I have been brewing about 2 batches per month for the last four years. All bottle-carbed. My problem tends to be in the opposite direction - overcarbed potential bottle bombs. Wanna trade? Maybe they'll even out!

There are three variables involved - 1) temperature, 2) sugar, 3) enough yeast. Natural carbonation is a bit of an art. Consistency in those three parameters will yield a consistent process. The goal is to add just enough priming sugar to the residual fermentable sugar so the yeast produce CO2 up to the point that the desired bottle pressure creates enough osmotic pressure on the yeast to turn them off. Clear as mud?

Temperature - especially consistent temperature - is the most important for both brewing and bottle conditioning processes. I did a "site survey", measuring temperatures around the house during various seasons. (My wife thought I was nuts.) The basement turned out to be the best all-around. The bottle aging area is conveniently next to the refrigerator.

Sugar is my biggest problem, especially estimating residual sugar. Sometimes the yeast will throw a head fake and stop bubbling, the gravity stabilizes, etc., but they're not really done. Under-pitching can also cause this because it significantly extends the fermentation time - Mr. Malty's pitch calculator is your friend. There are various priming charts around the net. Use them as an initial guess. My recipes and brew logs include priming sugar amounts.

Yeast tend to die in high-gravity batches and during long aging periods. Some yeast strains really floc out and don't make it to the bottling bucket. Clarifying processes, like cold-crashing in a keg and using gelatin also reduce residual yeast. Lately, I have been back-filling a small amount of yeast (about 1ml will do it) when I add the priming sugar. More glup in the bottom of the bottle, but it's cheap insurance.


In addition to the warm room, you could try adding a small amount of yeast to a bottle, re-capping, and see what happens. I tell my wife that I'm not drinking beer - I'm performing quality control!

If you don't mind, check back in a few weeks. I had one batch of Tripel that took a month. Most annoying.

 

[peterj]

There are three variables involved - 1) temperature, 2) sugar, 3) enough yeast. Natural carbonation is a bit of an art. Consistency in those three parameters will yield a consistent process. The goal is to add just enough priming sugar to the residual fermentable sugar so the yeast produce CO2 up to the point that the desired bottle pressure creates enough osmotic pressure on the yeast to turn them off. Clear as mud?

This is not really correct. There should be no residual fermentable sugar left in the beer when you put it in the bottles. All of the carbonation should be coming from the priming sugar.

Also, pressure will not turn yeast off. They will ferment just fine under way more pressure than it would take to blow up a bottle (which is why they can create enough pressure for bottle bombs).

 

[PerryS]

This is not really correct. There should be no residual fermentable sugar left in the beer when you put it in the bottles.

The fermentation curve is a decaying exponential. There is always some amount of residual fermentable sugar. The real question is whether it will be enough to affect carbonation. My rule of thumb is to bottle when the airlock is inactive for more than 120 seconds. Any longer, and the yeast may floc and not be enough in the bottling bucket.

As for osmotic pressure turning off the yeast, I will agree that it's a 3rd order effect. I personally see this with high-gravity beers and meads. It takes a combination of high alcohol, low residual, and high osmotic pressure to turn off yeast. It can help to give the beer/mead/wine a good shake after it appears to be done - this helps the yeast wake up again in the fermenter, chew through a bit more residual, so they don't wake up later in the bottle.

Cheers.

 

[passedpawn]

The fermentation curve is a decaying exponential. There is always some amount of residual fermentable sugar. The real question is whether it will be enough to affect carbonation. My rule of thumb is to bottle when the airlock is inactive for more than 120 seconds. Any longer, and the yeast may floc and not be enough in the bottling bucket.

As for osmotic pressure turning off the yeast, I will agree that it's a 3rd order effect. I personally see this with high-gravity beers and meads. It takes a combination of high alcohol, low residual, and high osmotic pressure to turn off yeast. It can help to give the beer/mead/wine a good shake after it appears to be done - this helps the yeast wake up again in the fermenter, chew through a bit more residual, so they don't wake up later in the bottle.

Cheers.

In my experience this all seems inaccurate.

Hoping for enough fermentable sugars in your near-finished beer is asking for trouble. Some breweries will keg just before fermentation is finished, thereby making a true Reinheitsgebot beer. I don't know of any that do this with a bottled beer. I sure wouldn't recommend it. When they keg this way, the timing is based on gravity measurements to determine the timing.

I'm pretty certain that bottling without priming sugar will result in utter failure.

Basing ANY decisions on frequency of bubbles in the airlock is a really bad idea. CO2 gets released all the time just from slight changes in temperature of the beer, barometric pressure, gas finding nucleation points in flocculating particles, etc. Many times, gas finds paths around airlocks or bucket seals and bubbling seems to stop.

I bottled a LOT of batches of beer (I always keg now though). There was ALWAYS enough active yeast to carbonate the beer, even when the beer was left in the carboy for extended fermentations. This includes many lagers. I always cold crashed the beer, and also used gelatin to clear as much of the suspended material as possible before bottling. And still, they always carbonated in 2-3 weeks.

The idea of pressure affecting the yeast isn't realistic. There are brewers right here on this forum who completely ferment under pressure (not sure why though). To alter yeast morphology or have any effect on budding or cell respiration, you'd need to exceed 5000 psi. Below that,

[edit: sorry for the truncated post, took a phone call and forgot what I was doing; it was long enough anyway ]

 

[azazel1024]

You really don't need to use any soap on them, unless you just insist on it. A simple rinse in tap water, or a nice soak in tap water to remove labels, and then a star san dunk at bottling time is all that you need. I've tried many methods over the years and I finally found the simple one was the best for me. It sounds like your rinsing plenty, so I doubt that was your problem anyway. Even if there was some left in there, it wouldn't change the amount of C02.

All this talk of bottling is making me want to evict some yeasties from their 12 ounce, 1 cap apartments, but unfortunately I have to work tonight....sigh.

Only time I use oxy on my bottles is if when I am going to rinse and then bake them for bottling day, I find mold or junk dried on to the bottle. Then I'll do a hot water and oxy soak for 10-15 minutes and through rinse. If that isn't enough to clean the gunk out (dear wife forgets to rinse bottles sometimes. Could never be me after my 5th home brew. Never!), I'll either chuck the bottle or let it soak for a couple of hours a second time, rinse and reuse the bottle on another batch (or chuck it if it still isn't clean).

 

[peterj]

The fermentation curve is a decaying exponential. There is always some amount of residual fermentable sugar. The real question is whether it will be enough to affect carbonation. My rule of thumb is to bottle when the airlock is inactive for more than 120 seconds. Any longer, and the yeast may floc and not be enough in the bottling bucket.

As for osmotic pressure turning off the yeast, I will agree that it's a 3rd order effect. I personally see this with high-gravity beers and meads. It takes a combination of high alcohol, low residual, and high osmotic pressure to turn off yeast. It can help to give the beer/mead/wine a good shake after it appears to be done - this helps the yeast wake up again in the fermenter, chew through a bit more residual, so they don't wake up later in the bottle.

Cheers.

I suppose in theory it may be a decaying exponential curve. But in practice the curve should reach a point in a reasonable amount of time where the difference between the actual number and the asymptote that it is approaching is insignificant. At that point the level of fermentable sugar will be so small that it will have no noticeable effect on carbonation levels (if there even is any actual fermentable sugar left).

As passedpawn said, airlock activity should never really be used to make any decision when it comes to brewing for all of the reasons he mentioned. And I also agree with him that it is very hard to get enough yeast to flocculate out of a beer that it won't be enough to create carbonation. I've never had a problem with it. Maybe if you aged and/or lagered a beer for a year or longer, but it's not likely to happen under normal circumstances.

You never clarified as to the osmotic pressure of what solute you were talking about. I assumed it was dissolved CO2. Dissolved CO2 can inhibit yeast cell growth, but there isn't too much of that going on in bottle carbonation. And at the partial pressures involved in bottle carbonation there isn't a lot of inhibition anyway. It may have a small impact on the speed of fermentation, but again there's not much decrease at bottle pressures.

 

[ncbrewer]

The fermentation curve is a decaying exponential. There is always some amount of residual fermentable sugar. The real question is whether it will be enough to affect carbonation. My rule of thumb is to bottle when the airlock is inactive for more than 120 seconds. Any longer, and the yeast may floc and not be enough in the bottling bucket.

I hope you will consider some of the advice offered here. You really can get what is considered "stable gravity", even if technically it is not. By bottling before reaching stable gravity, you are risking bottle bombs, as you mentioned. I would really hate for this to happen. Be safe.

 

[azazel1024]

I have been brewing about 2 batches per month for the last four years. All bottle-carbed. My problem tends to be in the opposite direction - overcarbed potential bottle bombs. Wanna trade? Maybe they'll even out!

There are three variables involved - 1) temperature, 2) sugar, 3) enough yeast. Natural carbonation is a bit of an art. Consistency in those three parameters will yield a consistent process. The goal is to add just enough priming sugar to the residual fermentable sugar so the yeast produce CO2 up to the point that the desired bottle pressure creates enough osmotic pressure on the yeast to turn them off. Clear as mud?

Temperature - especially consistent temperature - is the most important for both brewing and bottle conditioning processes. I did a "site survey", measuring temperatures around the house during various seasons. (My wife thought I was nuts.) The basement turned out to be the best all-around. The bottle aging area is conveniently next to the refrigerator.

Sugar is my biggest problem, especially estimating residual sugar. Sometimes the yeast will throw a head fake and stop bubbling, the gravity stabilizes, etc., but they're not really done. Under-pitching can also cause this because it significantly extends the fermentation time - Mr. Malty's pitch calculator is your friend. There are various priming charts around the net. Use them as an initial guess. My recipes and brew logs include priming sugar amounts.

Yeast tend to die in high-gravity batches and during long aging periods. Some yeast strains really floc out and don't make it to the bottling bucket. Clarifying processes, like cold-crashing in a keg and using gelatin also reduce residual yeast. Lately, I have been back-filling a small amount of yeast (about 1ml will do it) when I add the priming sugar. More glup in the bottom of the bottle, but it's cheap insurance.


In addition to the warm room, you could try adding a small amount of yeast to a bottle, re-capping, and see what happens. I tell my wife that I'm not drinking beer - I'm performing quality control!

If you don't mind, check back in a few weeks. I had one batch of Tripel that took a month. Most annoying.

I've been having the same issue of residual sugars in the beer and over carbing, plus at least a couple of what I am 95% sure were mild infections in the bottle (had an iron tang to them and were starting to massively over carb, including one bottle bomb).

A combination of replacing ALL of my bottling equipment other than my bucket, increasing sanitation (oxycleaning the crap out of it before and after bottling, not simply soap and water and then idophor and water) combined with warming the temperature of lagers after 10 days from lager temps to mid 60's F and with ales after about 5 days warming to around 70F seems to have fixed it.

I'll have to wait and see with the current 3-4 batches I've bottled in the last few weeks, as sometimes it took 5-8wks before a batch showed the apparent "way too much" carbonation, but so far it seems like I am good.

My Pilsner turned out to be slightly undercarbed (because I went with the 40F temp in the priming calculator when I probably should have used the 68F that it had been at its warmest point post fermentation). My English Pale Lager, Schwarzbier and Berliner Wiesse all seem to be roughly at the proper carbonation levels that I had been shooting for. My RIS, Belgian Single and English Milds are unknown at this point as they have only been in the bottle for 8 days, 15 days and 2 days respectively.

So I am hoping I have it licked, because since last summer has been way too overcarbed. I also adjusted my priming to use a calculator as well as proper volume measurement (I was going with 5oz per 5 gallons, now with a priming calc, I know with my typical 2.2-2.5v I really want to be around 3.4-3.7oz per 5 gallons).

Only beer so far that has seemed under carbed has been that Pilsner, which is probably more like 1.8v instead of the 2.6 I was going for.

 

[ncbrewer]

AZAZEL1024-Good luck with the fix - sure hope it continues to look good.