Priming a Hefeweizen in a keg

Brewing Processes
1

So I thought I would try priming my Hefeweizen in the keg.  I racked onto a 7 ounce solution of sugar and attached a spunding valve to monitor CO2.  I put 20 psi of head pressure on the keg and watched…it dropped to about 10 psi and has gained back to 20 psi over the last few days.  The keg is at 72F.

My question is - what psi should I let this go to before bleeding off CO2 in order to achieve the equivalent of 4 volumes of carbonation at serving temperature?  I can’t find a chart that goes high enough in the temperature range, as most charts deal with force carbing at particular temperatures (closer to serving temp range).

I intend to serve it at a club meeting in early August.  Thanks in advance for any help you can give me and I realize that I can “top off” the keg with forced CO2 at serving temp, but I wanted to be able to say that the keg was naturally primed, if possible.

2

54 psi at 72°F.  Four ounces of sugar would have got you there with a keg.

Edit - 4 volumes is pretty high. You may have trouble pouring especially if you are bringing the keg someplace and relying on a picnic tap.

3

I will be bringing growlers, so no problems there.  I doubt that I will achieve the 54psi and I have the spunding valve to relieve pressure, so where would I achieve 3.5 volumes at 72F?

Thanks for the input!

4

46 psi according to beersmith. Google carbonation calculator. Tasty brew has one.

5

Thanks, Steve. I will bookmark those sites for future use!