Brite tank carbonation

[timtoos]

I have a SS Brewtech brite tank that I always struggle with carbonation levels.

I have a beer sat in at the moment, at 3.5C. I want about 2.3 volumes of CO2 so using the carbonation stone fed in CO2 until I reached about 9psi, doing this slowly over 2 days. I achieved 9psi on 10/5. Today I have checked, 12/5, and the pressure is 8psi.

Is this drop due to the beer absorbing some of the CO2 held above it?

What do I do now? Leave it or add more CO2 until 9psi is reached again?

Regarding storage. Do I leave a top pressure of the carbonation level I want for the batch or reduce down to say 3-5psi?

PS, I can feed CO2 into the top of the brite tank or through the carbonation stone.

Thanks

[f00b4r]

CO2 will continue to go into the beer until it is in equilibrium, so it looks like it was not at the level that you wanted. You can drop the pressure but why would you want to? If you drop the pressure the CO2 will equalise to the headspace in the other direction.
The above is only true at a constant temperature, if it is fluctuating the CO2 will be jumping in and out of solution and your carbonation levels will change.
3.5C is pretty cold, is that for a reason or just to carbonate it faster?

[timtoos]

Hi, I thought the colder the better when carbonating, using less CO2? Is this incorrect?

[f00b4r]

It will absorb faster so carbonate quicker and it will require less pressure at colder temperatures but are you then planning to serve at that temperature?

[timtoos]

Probably not, but will probably chill it at the very least.

Will it be over carbed at my serving temperature?

Thanks

[f00b4r]

It won’t be overcarbed at a higher serving temperature but you will need to adjust the pressure to hit the same CO2 volumes at the new temperature.