Carbonating Question

First post and first batch in 21yrs. I brewed about 10 batches in the early 90's then stopped.
I brewed a batch of my favorite hefe and kegged to the corny. I am applying 30psi for 2 days per pappazian. That book is still the go to for me. My question is this: I forgot to purge the oxygen out, will this be a problem? I will be drinking tonight hopefully.

Theoretically, it could be a problem. Practically, however, it most likely will not be as the heavier CO2 will have displaced the O2 and pushed it into the headspace and away from your beer. I'd vent it as soon as you can, though.

There's no reason why you can't purge it at this time if your keg has a pressure relief valve.

That's why I didn't purge. I got 3 kegs from my old brewing buddy and none of them have relief valves. I just went home to purge and realized this dilemma. For now I just disconnected the co2 line and purged using a screw driver to vent. Then reapplied co2 line at 30psi.

LLBeanJ said:

Theoretically, it could be a problem. Practically, however, it most likely will not be as the heavier CO2 will have displaced the O2 and pushed it into the headspace and away from your beer. I'd vent it as soon as you can, though.

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Nah, they're going to mix, not stay separate forever. Gases mix much more readily than liquids. The CO2 will certainly start out right above the beer, but it'll all be uniform a short while later due to kinetic theory / brownian motion.

But I do agree that it's not that big of a concern, you probably won't notice anything as long as you aren't aging the beer for a long time. And since it's a hefe, you should be drinking it fresh anyway! Purging through the poppet like you just described was the right thing to do.

Welcome back to the hobby!

Thanks zachattack!
One more question. Where should my psi be at when ready to start serving?

That depends on your desired carbonation level, and your system's ability to properly serve at your desired carbonation level!

A hefe is best strongly carbonated, so I'd aim for something at least in the range of 3 volumes of CO2. You can use a kegging carbonation chart or calculator (I like this one) to find what pressure that would be given your beer temp.

Using that calculator, if your beer is at 40 deg F, applying 18 psi or so will maintain 3 volumes of CO2 in the beer.

But... unless you have nice long lines, it's going to be difficult for you to pour without excessive foaming. The friction of the beer flowing through the tubing slows it down, and it's important to slow it down enough so that it's not flying through the faucet like a rocket. If it comes out too fast, you'll have nothing but foamy pours.

Most kegging systems come with 5' of 3/16" ID vinyl beer tubing, and that's almost always not long enough. To serve at 18 psi you're probably going to want closer to 12 feet of the same tubing.

I'd recommend checking out how long your beer line is, and making sure it's at least 10 feet. It's worth replacing if it's shorter than that. Otherwise, your carbonation levels will be limited by your short tubing. Nobody likes a foamy pour!

Boy home brewing has gotten technical. Thanks for the link. My line is shorter then 5ft so new line is in order. If this all adds up to a kick ass brew then its all worth it. Where I live all the small breweries have forgotten the hefe. Its all flavored or filtered. Thanks again.

The technicality is half the fun! At least for me

Make sure you report back with the new line, let us know how it pours. We can help troubleshoot foaming, but the first step is always longer lines. Enjoy that hefe! Where are you located? I haven't any too many great domestic (US) hefes, but Kellerweis from Sierra Nevada is definitely my favorite.

Jumping in a different discussion... I started making smaller batches (2.5 gallons).. gave me right around 1 case of homebrew.. when I bottled I used the ratio of 1/2 cup corn sugar to 1 cup water.. boiled .. dropped to 70.. added to bottling bucket then racked ontop and bottled... never had a problem.. then I moved on to 5 gallon batches which Ive just kegged for simplicity. Now my question is if I want to bottle a 5 gallon can I just double my previous calculations and to 1 cup corn sugar to 2 cups water... thanks as always guys... cheers

horsepackage said:

Now my question is if I want to bottle a 5 gallon can I just double my previous calculations and to 1 cup corn sugar to 2 cups water...

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For 5 gal batches i use 5 oz priming sugar (corn sugar) in 2 cups water and boil. Hope this helps.

5 ounces of priming sugar should go OK for most batches, but a lot of us like to be more precise and use a priming calculator to try to nail a specific carbonation level.

http://www.northernbrewer.com/priming-sugar-calculator/

It's better to measure by weight, rather than volume. And you can use the much cheaper table sugar if you want (I do) but you do have to use less of it. So just follow the calculators.

zachattack said:

The friction of the beer flowing through the tubing slows it down

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I thought it was the mass of the beer in the line ahead of it that slowed it down? Longer lines = more beer to be pushed = slower flow. Wouldn't friction cause massive foaming inside the line?

OK time to give an update. By the way the excitement when you are getting ready to tap that first one is immense....and nerve racking. You just want it to be right. I put on 10ft line. I started at 7psi and it moved real slow with no foam. Upped it to about 10psi and still slow but not as slow. No foam. By the way the beer is rock solid awesome.
Question: you were right about 18psi but won't that keep carbonating the beer? I remember only ever tapping at 7psi back in the day but then I only used about 4-5ft of hose.

kombat said:

I thought it was the mass of the beer in the line ahead of it that slowed it down? Longer lines = more beer to be pushed = slower flow. Wouldn't friction cause massive foaming inside the line?

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Nope, it's friction. That's why the barrier tubing (with a much smoother liner) shows less resistance, and why larger ID tubing shows much lower resistance, even though there's a lot more beer in the line. Friction and the gradual drop in pressure doesn't cause foaming, rapid changes in pressure do. Like 10 psi beer dropping to 0 when it exits the faucet.

lawlessamps said:

OK time to give an update. By the way the excitement when you are getting ready to tap that first one is immense....and nerve racking. You just want it to be right. I put on 10ft line. I started at 7psi and it moved real slow with no foam. Upped it to about 10psi and still slow but not as slow. No foam. By the way the beer is rock solid awesome.
Question: you were right about 18psi but won't that keep carbonating the beer? I remember only ever tapping at 7psi back in the day but then I only used about 4-5ft of hose.

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A nice slow pour is what you want, that's the whole point of the longer tubing. Since this is just a home draft system, your profit margin doesn't depend on the number of beers you can pour in an hour. I think you'd agree that a slow, foam-free pour is much better than a fast foamy pour.

If you follow one of the charts/calculators, that will give you the CO2 pressure you need to maintain over the keg to keep the beer at the desired carbonation level. So if you want 3 volumes of CO2, you need to keep the keg at 18 psi. (Again, assuming you're at 40 deg. It's important to know your exact temperature.)

The most reliable way to carb and serve the beer is to use one of the calculators, set the pressure appropriately, walk away for 2 weeks, then start drinking. The pressure is kept the same through carbonating and serving. If you can't serve foam-free at the required pressure, it's likely because your lines aren't long enough. You can turn the pressure down to serve, but that wastes CO2 (with all the purging), is a pain in the ass, and the keg will lose carbonation if you keep the pressure lower for too long. Additionally, CO2 can break out of solution to try and balance the pressure, which can lead to more foaming. So it's a lot easier to pick a pressure and just stick with it.

Check out this awesome thread:
https://www.homebrewtalk.com/f35/keg-force-carbing-methods-illustrated-73328/

Zach you are a plethora of good information. Almost as good as the hefe I brewed. You asked where I live earlier and that would be York,pa. Thanks again for the quick responses and great info. The first one after work goes to you.