Foamy Second Pour from Keezer?

[tomakana]

So, I built a Keezer with a 3-tap DIY iron pipe tower over the pandemic, and so far I'm absolutely loving it. I've encountered one odd thing, though. I have 2 beers on tap (seltzer on the third) - one's a local craft brew in a sixtel, the other is one of my homebrews in a 2.5 gallon corny. For either of the beers, my first pours are perfect - good head, not a lot of foam. That would seem to indicate that everything is pretty well balanced, I think?

However, when I go back a little later for a second glass of the same beer, it's really foamy! In both cases, the parameters are roughly the same:

BL = 10'
Diameter = 3/16" ID
Temp = 36F
Rise = ~3 ft
Serving Pressure = 12psi
Taps are Nukataps.

In both cases, only the last 18" or so of beer line is in the tower, so I think if it were a tower cooling issue, I'd be seeing the problem on the first pour rather than the 2nd, based on what I've read of that issue in the past.

My working theory at the moment is that when I don't have a beer for a while, the temps and pressures equalize throughout the system, which means the first pull is clean even if my tower is a little warmer than the rest of the line. But once I draw beer from the system, cold beer from the keezer moves into the tower, where the temp is higher, warming the beer and leading to a foamy pour 20 minutes later before everything has leveled out again. That means I should try to equalize the tower temps more (which I was probably going to get around to eventually anyway, once I saw how big an issue it turned out to be).

Does that sound like I'm on the right track, or is there any thing else I should be focusing in on if that doesn't fix it? I don't know what the actual temp in the tower is, but I can find out fairly easily - if I bring it down closer to the beer temp, think that will solve this?

Thanks!

 

[Golddiggie]

12psi is too high at 36F.
https://www.glaciertanks.com/site_templates/Custom/img/beer-carbonation-chart.jpg
Use the chart to get the correct serving pressure for the beers.

If you're looking to have the seltzer at a higher carbonation level, then you'll need to either get a dual body regulator, or feed the beers from a secondary regulator set to the correct serving pressure for them.

 

[tomakana]

12psi is too high at 36F.
https://www.glaciertanks.com/site_templates/Custom/img/beer-carbonation-chart.jpg
Use the chart to get the correct serving pressure for the beers.

If you're looking to have the seltzer at a higher carbonation level, then you'll need to either get a dual body regulator, or feed the beers from a secondary regulator set to the correct serving pressure for them.

I have a 3-way secondary regulator already, so the seltzer's on it's own PSI. The two beers are actually somewhere between 10-12 -- to be fair, I lowered the temp from 38 at one point without adjusting the regulator, so that can be adjusted down a bit.

Based on the chart, I'm slightly above the high-end for "most beers" from a volumes of CO2 perspective (2.67 vs 2.4 to 2.6). Is that enough to cause 3/4 of a pint of foam?

Also - what would be the mechanics of the first pour being fine, then the second pour being foamy? Is the possible temp diff in the tower releasing the carbonation from the first ounce or so, then it all happens to even out over the pint?

 

[Golddiggie]

IME, if you go above the top entry for the style, you'll be getting a lot of foam. I had my regulator set at 13psi at 40F and it was heavy foam. Reduced to 12psi and set the temp to 41F and things are nice again. So even a couple of psi can make a significant difference. I would also not target the top of the range, but at least one step below there. It's easier to increase the pressure to get what you want than reduce it and get the keg to stabilize (can take days).