Well, my usual frame of reference, 15 bbl in 30 carbs faster than 30 bbl in 60 carbs faster than 30 bbl in 30 carbs faster than 60 bbl in 60. This is with volumes of CO2 being directly measured, and carbed with a stone at set pressure and CO2 flow rate, and blown down to equilibrium pressure (based on the chart we all know) once target carb is reached.Is that really true given the interface area is unchanged?
I have no idea. I work with ones and zeroes I usually look to @doug293cz for such matters...
Cheers!
I really can't get my head around this statement. Why should pressure increase just because the bubble gets smaller? In an equilibrium state pressure inside the bubble will always equal hydrostatic pressure outside the bubble. If this weren't the case then the bubble would just contract or expand until both pressures equalize. The former (contraction) is exactly why the bubble gets smaller as CO2 is absorbed. As CO2 diffuses into the beer pressure in the bubble decreases and the bubble contracts keeping the internal pressure equalized with the external.Another factor that speeds carbonation with bubbles is that as the bubbles dissolve and get smaller, the pressure inside the bubble increases, speeding up the rate at which CO2 dissolves from the bubble into the beer.
The pressure inside a bubble is higher because of surface tension. Surface tension provides a force trying to collapse the bubble to eliminate the surface which has higher energy than the bulk. The surface tension force must be balanced by a pressure increase inside the bubble or the bubble would collapse. Read more about it here: https://en.wikipedia.org/wiki/Laplace_pressure. The Laplace pressure is the difference in the hydrostatic pressure outside the bubble and the pressure inside the bubble.I really can't get my head around this statement. Why should pressure increase just because the bubble gets smaller? In an equilibrium state pressure inside the bubble will always equal hydrostatic pressure outside the bubble. If this weren't the case then the bubble would just contract or expand until both pressures equalize. The former (contraction) is exactly why the bubble gets smaller as CO2 is absorbed. As CO2 diffuses into the beer pressure in the bubble decreases and the bubble contracts keeping the internal pressure equalized with the external.
What does happen though is that the surface to volume ratio of the bubble increases exponentially and so does the rate at which the bubble is further absorbed, hopefully leading to complete absorption before the bubble can reach the surface of the liquid.
Yes, a smaller volume of beer will carb faster than a larger volume of beer in the same style keg. It has nothing to do with headspace, it’s that less beer requires less CO2 to reach the same carb level. So, at a fixed rate of carbonation, a smaller volume will get more carbed in the same amount of time.Rats. My confirmation bias perhaps, but I thought I had found a decent burst carb sheet, giving reasonably good results, but it definitely shows higher carb achieved with more headspace(4.5 gal in 5.25 Vttl versus 4.8 gal in same 5.25 Vttl).
Or maybe it's showing faster. That might be it. I don't have it here to check.
Depends on just what the calculator is assuming. If, for example, you pressurized at 30 psi for X hrs, and then sealed off the keg, there would be more CO2 in the headspace at higher than equilibrium pressure, and that excess CO2 would get absorbed into the beer until the headspace pressure is in equilibrium. If you just pressurized at 30 psi for X hrs and then bled the pressure to equilibrium pressure, then no extra carb would result from the extra headspace.Right, of course. Lower vol of beer carbs faster.
But changing headspace, in the calculator I found, from 5.25 to 5.5 while leaving beer volume alone at 4.75, did change the overall vols CO2 by .03 so if headspace has no bearing then the math/physics of that calculator are in question.
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