Over-carbonated beer

[RM-MN]

I don‘t know I’ve never taken a Chemistry of Physics. i though there was a reason being most beer is filled an inch below the cap.

Have you ever toured a commercial brewery that bottles and watched them filling the bottles. I suspect that inch of space is to keep the bottles from spilling until they can get the cap on.

If you want to hear something quite different, try filling bottles half way and then capping them. It won't be a quiet phffft when you open one.

 

[hotbeer]

If you want to hear something quite different, try filling bottles half way and then capping them. It won't be a quiet phffft when you open one.

I did that last night. It was very impressive. This was my last bottle filled with the remaining beer from last weeks bottling that I opened to see how it was doing. Probably only 5 to 6 fl. oz.

There was a very long, slightly louder and satisfying pffft. The beer being only a week from bottling hasn't quite reached where I want it to be for carbonation, but it's very promising that this batch is on the right track compared to the previous batch.

 

[Inclinejj]

My thinking on the headspace thing is that is what gives you the satisfying phffft sound when you open the bottle.

The sound changes quite a bit depending on volume headspace more so than the pressure IMO. The smaller the head space the less phffft.

My bottles with 1/8" headspace had no phffft whatsoever. So I was very down trodden and thought my very first batch was flat when I popped that first cap off. However it was actually probably better than 3 vols just estimating from how long the poured glass stayed well carbonated.

 

[ncbrewer]

If you want to hear something quite different, try filling bottles half way and then capping them. It won't be a quiet phffft when you open one

Papazian wrote that a bottle that was filled to half full can become excessively carbonated and dangerous if it explodes. I think (not really sure) what he means is that it won't be higher pressure, but the additional gas in the headspace will make a more violent explosion in the event that it does explode. Maybe somebody else knows more about this than I do.

 

[hotbeer]

but the additional gas in the headspace will make a more violent explosion in the event that it does explode

Have you ever had a bottle explode? I haven't.

And I only know people that claim to know someone that has had a bottle explode. I'm sure it happens, but it's probably very rare and doesn't justify the number of threads talking about exploding bottles.

 

[RM-MN]

Have you ever had a bottle explode? I haven't.

And I only know people that claim to know someone that has had a bottle explode. I'm sure it happens, but it's probably very rare and doesn't justify the number of threads talking about exploding bottles.

I have. I got several batches infected by a wild yeast that just wouldn't quit making CO2. The wild yeast worked slowly so if I opened a bottle in 3 weeks it would be perfectly carbonated. 3 weeks later it would bubble out of the bottle after a minute. At 3 months I could have a beer volcano and if left the bottles would explode. It took some thinking as to why this happened and I tried several things to get rid of the problem, like putting a lid on the bottling bucket (slowed the process but they still became overcarbonated), bottled in my detached garage (just made me cold) and a countertop filter with a UVC light but the final answer was when my neighbor died, his cattle were sold, and the huge pile of corn silage disappeared. Apparently the pile of silage was the source of the wild yeast.

Once the silage was gone, I have had to regain confidence in my amount of priming sugar and have made a few batches that were minimally carbonated just to see that they did not become overcarbonated.

 

[doug293cz]

Papazian wrote that a bottle that was filled to half full can become excessively carbonated and dangerous if it explodes. I think (not really sure) what he means is that it won't be higher pressure, but the additional gas in the headspace will make a more violent explosion in the event that it does explode. Maybe somebody else knows more about this than I do.

Yes, it's the extra gas volume. The more the starting volume of the pressurized gas, the greater the volume required for expansion to relieve the pressure, and dissipate the energy stored in the compressed gas. Liquid is different, since it is almost in-compressible. Thus it takes very little expansion to relieve the energy stored in a compressed liquid.

However, it is also less likely that a half filled bottle will reach pressures great enough to explode. With only half the beer to start with, you only get half the CO2 generated, so half filled bottles are likely to be severely under carbonated if correctly primed, and less likely to explode if over primed (or infected.)

Brew on

 

[ncbrewer]

Have you ever had a bottle explode? I haven't.

And I only know people that claim to know someone that has had a bottle explode. I'm sure it happens, but it's probably very rare and doesn't justify the number of threads talking about exploding bottles.

Yes, I've had bottles explode. Only one in recent years. I must have missed some crud in the bottle because the rest of the batch was perfectly fine. I had some explode many years ago, but I don't remember the circumstances. It's enough of a hazard that I pay attention to anything that could cause an explosion, including hop creep, diastaticus yeast, bottle fill level, etc.