How to force carb in a week?

[kevinthestout]

Best to wait until you've got plenty of time if you want to try natural carbing in the keg. Most sources recommend two weeks not 2 days - there's no reason why it would be any quicker than bottle conditioning. Not everyone agrees that natural carbonation is better, and oxygen scavenging is only useful if there's a flaw in your process that introduces oxygen to start with. Also you may have to trim your dip tube to keep it out of the sediment, and there are other downsides to having yeast in your keg.

 

[schematix]

Best to wait until you've got plenty of time if you want to try natural carbing in the keg. Most sources recommend two weeks not 2 days - there's no reason why it would be any quicker than bottle conditioning. Not everyone agrees that natural carbonation is better, and oxygen scavenging is only useful if there's a flaw in your process that introduces oxygen to start with. Also you may have to trim your dip tube to keep it out of the sediment, and there are other downsides to having yeast in your keg.

I would agree that you should plan ahead to do this and have the right tools on hand (simple and inexpensive), but i do disagree with some of your points:

1. Time - if you rack reasonably soon after the beer has reached terminal gravity, the yeast will still be active and will happily, and quickly, consume all those simple sugars. I have pressure gauges on my kegs when i do this and you can see about 90% of the conditioning is complete in 2 days, and its only another day or two after that when it doesn't rise any further. Now if you've left that yeast on the cake for 4 weeks, then yah, it'll probably take longer. Your best bet is to rack when the beer has just finished (better yet, about 2-3 gravity points before finishing then you don't need priming sugar). I know a lot of people like to let the beer ride on the cake for a while, but it's just not necessary. I used to do 28 day primaries on everything and produced some decent clear beer. Now for ales i'm usually racking to kegs in ~3 days and the flavor and longevity is vastly improved. Game changer on IPAs.

2. Oxygen - even in the most diligently purged closed systems oxygen is a real problem and is virtually impossible to fix via mechanical means. Yeast is the best way to bring dissolved oxygen to near 0. Not looking to derail this into a low oxygen thread, but it's a real concern and conditioning is a real way to improve longevity of the beer.

3. Dip tubes - I'm usually through the sludge after the first half pint or so. I wouldn't suggest shortening them for serving kegs.

Good luck to the OP!

 

[Shade]

If it takes more gas you'll hear gas flowing through the regulator when you connect the QD.

I'm finding this easier said than done in my lack of experience. Possibly it's being drowned out by my fridge when I open the door (but I can turn that off I guess) but if it's happening, it's pretty quiet and/or quick. In my mind I'd think if the beer isn't carbed, the pressure in the headspace is going to be a few psi less than what the regulator is set to, and it's not going to take long to get to the 13psi I've got it set to, so hearing it flowing I don't get.

I do hear it when I force carb so I know what it sounds like at least.

It's also hard to judge by the beer itself since the first few glasses are cloudy and I can't see whether it's bubbling or not. I don't think it's fizzed enough but I can't observe it, it's just my tastebuds to go on, and having not done it before, I am unsure.

 

[kevinthestout]

It's also hard to judge by the beer itself since the first few glasses are cloudy and I can't see whether it's bubbling or not. I don't think it's fizzed enough but I can't observe it, it's just my tastebuds to go on, and having not done it before, I am unsure.

Taste (and mouthfeel) should be all you need.

Given you're short on time you might be better to try the crank and shake approach. Rack reg the pressure up to 30psi and attach the cold keg. Put the keg on its side and shake for 3 to 5 mins. Put it back in the fridge for 5 min. Pour a sample. It will probably be mostly foam. Ignore that, but see whether the liquid tastes carbonated enough. If not repeat, and be careful with the over-filled keg.

 

[Shade]

Party day!

The keg I had put on for 5 days at room temp and 23 psi I tried last night. It had visible bubbles but enough quite enough so I've cranked that up a bit.

The first keg was pouring 2/3 foam so I degassed it a couple of times and last night it poured better but I think undercarbed so cranked that a bit more too.

The overfilled keg is currently warm so I've had that back on at 23 psi without incident. Can't put it in fridge also so planning to put it in ice to keep it a bit cool so I can transfer it to the fridge when one finishes.

Fingers crossed they are all drinkable!

 

[stz]

The pressures discussed here seem really weird. I'm not saying they are wrong, if they work then great, but maybe regulator accuracy isn't great or sample method/dispense is still being fine tuned?

In a pinch we'll force carb kegs with top pressure in 40 hours at 22psi at cellar temperature (10C?). It'll definitely over carbonate if left longer, the method balances a need for speed with a need to not over or under shoot and handily means if you set it monday night, you shut it off wednesday morning, wednesday night then to friday morning, friday night then to sunday morning and so on.

We batch carbonate a smaller 1,100L tank which struggles to get down below 3C. Once it is at temperature it takes about 2 days at 22psi using a bottom sinter. 22psi is a lot, but there is wetting pressure of the stone as well as hydrostatic pressure to compensate for so knock about 10psi off that for what the tank sees.

We carbonate several larger 2,200L, 2,400L, 2,600L tanks using top pressure alone (please don't make fun!) and because we can hold these at 0C reliably we can carbonate the lot pretty much in the same day at 22-24psi if needed (working pressure of the tanks) though we don't really need to, 10psi still gets us there in 2 days.

My point is that in all of these cases the theory supporting carbonation charts for a set and forget method works and it works pretty fast. I often leave stuff for 5 days, sometimes several weeks, but it never actually needs that long with the gas on and if it isn't there something else is wrong.

Every stumbling block I've had on the way has been down to sampling method. It is next to impossible to get an accurate sample out of a pressurised tank without the back pressure involved in a well designed keg line. We looked at a pig tail stainless steel glycol jacketed coil for sampling, in effect several meters of microbore tubing to provide the necessary back pressure and to super chill the beer. It is easier to just fill a keg and put it on the bar, 99% of the time we are there now anyway.

 

[seabrew8]

Natural carbonation IMHO is the best way to go for kegging and is waaaay under hyped. If you get a spunding valve you can just set the pressure to match the actual temperature and desired carbonation level. I normally use about 2-3oz of priming sugar per keg and that always seems to be more than required. Aim just a little high and any excess pressure will be vented. Your serving CO2 tank will last A LOT longer too.

Yeah i too now prime my kegs. I'm away working for weeks at a time so it just makes sense.

I have a 20lb tank i expect it to last a few years!

 

[seabrew8]

The pressures discussed here seem really weird. I'm not saying they are wrong, if they work then great, but maybe regulator accuracy isn't great or sample method/dispense is still being fine tuned?

In a pinch we'll force carb kegs with top pressure in 40 hours at 22psi at cellar temperature (10C?). It'll definitely over carbonate if left longer, the method balances a need for speed with a need to not over or under shoot and handily means if you set it monday night, you shut it off wednesday morning, wednesday night then to friday morning, friday night then to sunday morning and so on.

We batch carbonate a smaller 1,100L tank which struggles to get down below 3C. Once it is at temperature it takes about 2 days at 22psi using a bottom sinter. 22psi is a lot, but there is wetting pressure of the stone as well as hydrostatic pressure to compensate for so knock about 10psi off that for what the tank sees.

We carbonate several larger 2,200L, 2,400L, 2,600L tanks using top pressure alone (please don't make fun!) and because we can hold these at 0C reliably we can carbonate the lot pretty much in the same day at 22-24psi if needed (working pressure of the tanks) though we don't really need to, 10psi still gets us there in 2 days.

My point is that in all of these cases the theory supporting carbonation charts for a set and forget method works and it works pretty fast. I often leave stuff for 5 days, sometimes several weeks, but it never actually needs that long with the gas on and if it isn't there something else is wrong.

Every stumbling block I've had on the way has been down to sampling method. It is next to impossible to get an accurate sample out of a pressurised tank without the back pressure involved in a well designed keg line. We looked at a pig tail stainless steel glycol jacketed coil for sampling, in effect several meters of microbore tubing to provide the necessary back pressure and to super chill the beer. It is easier to just fill a keg and put it on the bar, 99% of the time we are there now anyway.

In my experience to force carb a cold corny keg you can do it in 1-2 days at 40 psi. It will not be over carbed, just check it every day.

 

[stz]

In my experience to force carb a cold corny keg you can do it in 1-2 days at 40 psi. It will not be over carbed, just check it every day.

It isn't the same as leaving the pressure on at the correct level until the beer is both conditioned and carbonated, but honestly if you can rack a beer into a corny (beer cold crashed to 1C so pretty frosty) and put head pressure onto it, gently put it onto its side so the head space becomes quite large and roll it back and forth you can watch the regulator drop as the co2 dissolves into the beer. You can do this for as long as you want until it stabilises and theoretically get the whole thing done in minutes.

Quarter barrel kegs carbonate with top pressure for us in 40 hours at 22psi because the head space is fixed. It'll be the same for you with 2 days at 40psi and a corny. It is handy to figure to have the technique dialled in with that fixed variable.

 

[seabrew8]

It isn't the same as leaving the pressure on at the correct level until the beer is both conditioned and carbonated, but honestly if you can rack a beer into a corny (beer cold crashed to 1C so pretty frosty) and put head pressure onto it, gently put it onto its side so the head space becomes quite large and roll it back and forth you can watch the regulator drop as the co2 dissolves into the beer. You can do this for as long as you want until it stabilises and theoretically get the whole thing done in minutes.

Quarter barrel kegs carbonate with top pressure for us in 40 hours at 22psi because the head space is fixed. It'll be the same for you with 2 days at 40psi and a corny. It is handy to figure to have the technique dialled in with that fixed variable.

i rather not dial in. I make homebrew.

 

[doug293cz]

It isn't the same as leaving the pressure on at the correct level until the beer is both conditioned and carbonated, but honestly if you can rack a beer into a corny (beer cold crashed to 1C so pretty frosty) and put head pressure onto it, gently put it onto its side so the head space becomes quite large and roll it back and forth you can watch the regulator drop as the co2 dissolves into the beer. You can do this for as long as you want until it stabilises and theoretically get the whole thing done in minutes.

Quarter barrel kegs carbonate with top pressure for us in 40 hours at 22psi because the head space is fixed. It'll be the same for you with 2 days at 40psi and a corny. It is handy to figure to have the technique dialled in with that fixed variable.

For carbonation, headspace volume is irrelevant. The only variables that matter are: CO2 partial pressure, beer temperature, and the ratio of gas-beer interface area to beer volume. Increasing the interface area increases carbonation rate. Bubbling CO2 thru the beer drastically increases the gas-beer interface area. Shaking also increases the interface area.

Edit: Forgot one other variable - the current carbonation level of the beer (CO2 concentration in the beer.)

Brew on

 

[stz]

For carbonation, headspace volume is irrelevant. The only variables that matter are: CO2 partial pressure, beer temperature, and the ratio of gas-beer interface area to beer volume. Increasing the interface area increases carbonation rate. Bubbling CO2 thru the beer drastically increases the gas-beer interface area. Shaking also increases the interface area.

Edit: Forgot one other variable - the current carbonation level of the beer (CO2 concentration in the beer.)

Brew on

Fair point. For accuracy when I say head space I should actually say surface area for beer/gas interface. Quarter and half barrel kegs have a slightly convex top like corny kegs. When they are almost completely full the interface area is tiny compared to when they have lost 500ml and if we have to force carbonate this can throw things out of whack. Variable fill level within this portion has resulted in a few returns within batches.

We now run out a little beer to a known weight. Once you are out of the domed portion the surface area remains constant if the kegs are vertical and as such it works the same every single time.

 

[doug293cz]

Fair point. For accuracy when I say head space I should actually say surface area for beer/gas interface. Quarter and half barrel kegs have a slightly convex top like corny kegs. When they are almost completely full the interface area is tiny compared to when they have lost 500ml and if we have to force carbonate this can throw things out of whack. Variable fill level within this portion has resulted in a few returns within batches.

We now run out a little beer to a known weight. Once you are out of the domed portion the surface area remains constant if the kegs are vertical and as such it works the same every single time.

Yes.

Brew on

 

[Shade]

Anyway .. a post-party update. So, the set and forget beer had the best carbonation easily. The other two were overcarbed but we made do. Frequently they poured half-foam, even with no gas attached, and the best pours were when we left the gas off for a while.

But overall was a grand success - 1 keg tapped and the other two left with very little to go.

And learning was set and forget is probably the way to go!