pressure rating for tallboys?

[Cheeno]

I was about to bottle a brew that had been sitting around for awhile (which I thought must have been ready) but I when a read the SG it was a little high. It got me wondering: some people bottle by time or by other signs than a hydrometer - is there way to work out how much pressure an un-fully fermented beer can develop as it matures. Don't get me wrong, I'm quite happy to let this beer finish in the fermenter HOWEVER LONG IT TAKES. I just thought about people who may bottle every fortnight (for example) using different recipes at different temps. For instance the aforementioned brew is at 1.016 and I'm after 1.1010, if I bottled now how much more would the hydro drop? What would the extra pressure be on a full 800ml bottle? Does anyone know what the standard pressure of an 800ml bottle is?

[gregb]

If the SG is static over 24+ hours, then it should be ok to bottle.

Cheers,
Greg

[Oliver]

Cheeno,

As far as I know, a hydrometer is the only sure, practical way a homebrewer can tell if a beer is finished fermenting.

Oliver

[Cheeno]

Thanks for your replies guys. I was more trying to get the math on the pressure of a full bottle of beer - just for the sake of discussion. I agree about hyrdo's but I think the '2 consecutive readings over 2 days' needs to qualified with the fact you need that reading to be in the vicinity of where your ingredients indicate it should be. To go back to my "Forever and a day" Ale; with the drop in temps all action ceased and it sat on 1.016 for about a week. Wih just a slight rise in temps (not back to what they were when the brew started) she's gently ticking over again. Now this ale yeast seems to be working at about 14-16C. There was a time, not long ago, when I was that 'thirsty' I would've bottled anyway. Once again I was just wondering if there is some formula like: "one 'extra' hydro point = one extra p.s.i." or the like.