Is bubbling CO2 during the Boil problematic?

[BigBlock]

Would small amounts of CO2 being bubbled during the boil impact the flavor/chemistry of the beer?

Background:
I'm working on some automation and wrote some code for my bubbler level sensor (http://playground.arduino.cc/Main/Waterlevel). After getting it running last night, I'm looking for a means to reduce the noise in the signal due to supply pressure fluctuations. There are many ways to accomplish this through mech or control filtering (which I have in my code), but there is a huge difference between using a fishtank pump (noisy) and pulling off my 60gal compressor tank. Since I don't want my brew to taste like compressor oil, that option is out. I could use a secondary tank in series with the fishtank pump but its more claptrap that I'd prefer to avoid. I could also take the relatively small accuracy hit of using a check valve in the link provided, but I'd prefer to have a continuous system. So my thought is to use CO2 regulated way down with a needle valve to meter final flow. In terms of flow it should be less than 1cm^3/sec.

 

[ajdelange]

In a word: "no". It will never dissolve as the wort is too hot.

But why not just use a liquid pressure transducer connected to the kettle at the bottom?

In any case you will have plenty of 'noise' from the formation of and rising of steam bubbles. A volume of liquid shot through with steam bubbles doesn't have the same density as bubble free wort thus the density and hydrostatic heads are going to vary.

 

[BigBlock]

Thanks for the info... I did some proof of concept testing last night on reducing noise, but not with boiling yet. Using the regulated CO2 was night and day vs the aquarium pump (as expected), but the bubble side resulted in about 1inH20 of noise. I was able to filter this fairly well, but decided to try some mech dampening using 2 corney kegs to dampen the pulses from both the aquarium pump and the bubbles. So the setup was:


````````````````````DP sensor
aquarium pump->keg--------^-------->keg->bubbler tube


This reduced the noise by an order of magnitude and measurements were all less than 1/8". I was very pleased with that and probably won't bother to do much more filter tuning. Not sure if I'll use this setup or not as its bulky, but since its free I may go with it for a bit. I'm hoping to get some boil data tonight. I'm interested to see how much impact that the boil has on both the head measurement as well as the noise. I believe the steam bubbles will change both the density(decrease) as well as the height of the liquid(increase) through displacement, and hopefully be close to cancelling out. I could calc it, but it will be quicker to run the experiment. My hope is that the noise does increase as the boil becomes more vigorous and I can use this to quantify and maintain a good rolling boil without boiling over. High hopes, we'll see.


As for single liquid press transducer... I did consider that and I think it would work well, but I'm not sure I could get a cheap, food grade/heat tolerant version nearly as cheap as the mpx5010DP. There are some other +/- for each (clogging lines, etc), but nothing that seemed insurmountable.