[Lazy Ant Brewing]

I know from experience that bottles with lots of traub in them are over carbonated compared to those with less sediment.  And I've heard that's because the traub has more nucleation particles.

But is there somehow as much CO2 in the "cleaner" beer that simply is not available to come out of suspension or did the beer with more traub allow for more CO2 to form as the yeast produced alcohol? Sounds like the chicken and the egg quandary to me.

Explanation please and thanks in advance for helping me to understand this.

[Stevie]

I think you get it. The amount of co2 is identical, it's just the particles knock more out of solution. Similar to a "nucleated" glass vs a smooth glass.

[dmtaylor]

Carbonation comes from dissolved CO2 gas coming out of solution.  While I don't confess I understand exactly why this is true, I do know that CO2 loves scratches and imperfections, it gives it a reason to undissolve and bubble out of solution.  This effect can be accelerated with dramatic effect if you shake up a beer before opening it.  The air space inside the beer bottle or can will then be mixed thoroughly into the carbonated beer as tiny bubbles instead of just one single air bubble, so again the CO2 has a lot more surface to grab onto and can thus result in spraying beer all over your friend's face when he opens the container.

In much the same way, a beer with a bunch of crud moving around in the beer will always tend to have a bigger head, or might even seem overcarbonated when you first open the container.  Also, a hazy beer will always seem more carbonated than a perfectly clear beer, given identical volumes of CO2 gas dissolved in the beer, even though the actual amount of CO2 dissolved in the beers is identical.  It just comes out faster in the hazy or trubby beer than the clear one.  The clear beer will eventually lose the same amount of fizz, just much more slowly.  Meanwhile, the hazier beer will also tend to go flat sooner, like if you were to leave both beers sitting out for an hour before drinking them, the hazy beer would turn flat before the clear beer would, if all other variables were identical.  But of course, who leaves a beer out for a full hour before drinking it? 

That's my version and I'm sticking to it. 

[ethinson]

I think you get it. The amount of co2 is identical, it's just the particles knock more out of solution. Similar to a "nucleated" glass vs a smooth glass.

Is it identical though? I bottle condition everything, so I'm used to getting bottle to bottle variations.  It would seem to me that the bottles with more sediment had more carbonation because there's a higher yeast load in the bottle.  Bottles with no trub still have plenty of yeast in them to get the job done, but you throw a big slug of yeast in there and they are going to town.  Maybe they never got higher, sugar is a limiting factor, but they sure got done faster.

Purely anecdotal since I haven't measured it, but it seems to make sense.  Since as homebrewers we measure carbonation by sight and mouthfeel, you can probably tell a difference visually between 2 volumes and 3 volumes... but not a difference between 2.3 and 2.5.