Confused by PSI!

[thedisasterparty]

Hey guys. I need someone to explain some stuff about kegging to me. I'm not brand new to kegging, but the way i've always done it for near every beer I have kegged is i've basically cranked up the PSI to 25-30 and walked away for 2 days. I then come back, turn the system off, let pressure out and put it at 10 PSI for serving. The beer is usually decently carbonated and I'm happy.

However, I understand this isn't a good way to go about it if you're concerned about hitting the levels of CO2 needed for a style. I'm entering a Saison into my local competition here in a week or 2, and i'd like to have the right levels of carbonation. Using calculators online, it always comes up to around 6 or 7 PSI recommendations. This, being under the pressure I use for serving confuses me. Does this really mean I can set it to 6 PSI, walk away for a week, come back and i'll have correct carbonation? What do I use as a serving pressure at that point?

 

[AnOldUR]

Using calculators online, it always comes up to around 6 or 7 PSI recommendations.

There's something wrong. Can you link to the calculator that you used?

 

[outside92129]

Here are some charts i posted a while back with CO2 / volumes / temp:
https://www.homebrewtalk.com/f35/temperature-vs-co2-volumes-serving-beer-301592/

 

[thedisasterparty]

http://www.tastybrew.com/calculators/carbonation.html

Heres the calculator. Maybe i'm confused, is this PSI referring to something different than what I set my regulator to?

 

[PoorYorick]

Check out those charts that Outside posted. They will show you how many PSI to set your regulator to if your beer is sitting at what temp.... based on how many volumes of co2 you need/like in your beer.

 

[AnOldUR]

Not sure where TastyBrew gets their infomation, but from what I know Saison's are carbed around 3.0 volumes and are served at 54 degrees.

That puts you in the 15 to 25 psi range for both carbing and serving. You'll have to have a 10 foot or better beer line to prevent foaming.

Personally, I'd set my kegorator temperature at 45-50 degrees and the pressure at 15+ psi, set and forget.

Enjoy!

 

[erikpete18]

What temp is your beer at when you carb it? From the site you linked, if your beer was cold I could see getting psi recommendations that low. For what its worth, their suggested volumes for saison (1.9-2.4) seem on the lower side to me, but that depends on what you'd like the carb level to be. BJCP says the carbonation should be "very high", which to me leans more towards 3-3.5 volumes. Using the table that outside linked to, and assuming that your fridge is 34 degrees (measure to be sure), that would put you around 16-18psi.

For what its worth, the "set-and-forget" like you are mentioning normally takes me 2-3 weeks to get to a correct spot. It might actually be faster than that, but I feel like I've convinced myself its not tasting right until 3 weeks carbing, so I try to force myself to wait if I can.

 

[betarhoalphadelta]

Note:

1. A carbonation chart will show you how many volumes CO2 your beer will absorb at a certain temperature and pressure.
2. A line balancing calculator will show you how much line you need for a specific number volumes of CO2 to pour without foam.

You need to first determine what psi and temperature to get the expected number volumes CO2. The chart AnOldUR posted above will tell you this. (Saisons can be on the high end, say 2.8-3.0 volumes CO2).

As you point out, doing a "25-30 psi for 2 days" can cause issues -- most notably that it's an inexact method. You can't be sure that you don't overcarbonate the beer in that amount of time. If you undercarbonate, then leaving it a few days longer at the pressure suggested in the above chart will get it just right. But if you overcarbonate, then it's a lot more painful and time-consuming process to get it back where you want it.

But that's only the first half of the equation. The second half is how to get it into your bottles without losing all that carbonation due to foam. For that I recommend this: https://www.homebrewtalk.com/f35/we-no-need-no-stinking-beer-gun-24678/ -- if you do it this way, you can put it into bottles (best to freeze the bottles to avoid temperature-induced foaming) at the same serving pressure with basically no carbonation loss. This should work even if you don't have a well-balanced kegerator system, at least to get it into the bottles.