Conventional wisdom for competitions is ~ 1 inch, but other than aesthetics, is there a real good reason to leave this much room if the bottles will be refrigerated after carbing at a very controlled room temp? I ask because I've had a couple batches with excess volume that I have bottled some leftovers from a spigot with carb drops. Have I just been lucky or am I tempting fate?
I believe if bottle conditioning you need headspace for CO2 to form pressure and disolve into the beer. If keg carbonated you can fill to the top without issue.
I don't see any risk with overfilling your bottles, assuming you're using a normal amount of priming sugar. The CO2 will dissolve in beer without any headspace. The pressure comes from the volume of the gas itself, not the headspace.
I could have sworn that the last time I took a brew tour they hit hit their canning line with x-rays to make sure that it's 98% full. If it's not, apparently they run into issues with can bombs. Am I missing something here? Conventional wisdom be damned. Does CO2 that's disolved into beer still put pressure on the bottle?
We go through home brew too fast to have encountered any potential shelf life issues related to head space. The only thing I've noticed is that if there's almost no head space (e.g., 1/4" or less), then there's not much of the ppffffftt sound when you pry the cap off. Not enough volume to expand.
That seems to be cutting things awfully fine. The main physical difference between 98% full and 99% is that 1% liquid adds a little extra priming sugar to a confined volume. You'd see a proportional increase in CO2 production, but it seems an insignificant amount. I guess if you were really playing close to the engineering tolerances of the can, you would need a system in place that detects volume of beer to a very high degree, but I cannot imagine any probrewers would purposefully try to get so close to exceeding those tolerance.
I thought so too. I've not spent any time around pro brewers and I know little about canning lines. I'm still kind of curious to know how they can fill 110 cans a minute without spilling any.
