Keg pressure for dispensing / Glasses of foam!

[peebee]

This is a topic I see time and time again: What pressure to keep the keg at, and what pressure to dispense successfully? I maintain the pressure (8-12psi) and dispense very slowly, wait for the foam to abate, the top up very slowly. I put up with this tedium because only about 1/4-1/3 of my beer is served as keg, the rest is hand pumped with the beer at below 2psi so dispensing isn't an issue. But I hear of others with carefully calculated lengths of beer line, or that drop the keg pressure to about 5psi for serving before restoring the pressure at the end of session.

Basically, serving keg beers (and not glasses of foam) can be a pain in the …


Moving on, and an entirely different subject. I'm keen on brewing low-alcohol beers and ferment in the dispensing keg, under pressure using "spunding" valves. I'm perfectly happy with the regulators I've repurposed as very accurate low-pressure "spunding" valves. But recently I was made aware of purpose built valves made (in China) for an Australian bunch called "Kegland". So I ordered a couple, they are called "Blowties", via AliExpress to play with. At the same time I noticed some plastic secondary regulators based on the same design as the "Blowtie", so I got a couple of them (they were only a couple of quid) to play with too. The description said "suitable for gas or liquid"; what on earth would you want a wet regulator for?


Back to dispensing glasses full of beer foam: I'm bored of taking five minutes to pour a glass of my keg beers. I'm very unimpressed with all the faffing about with "beer line calculators" and "balancing kegs" or the idea of dispensing at low pressure and having to restore the pressure after serving. Is there not a better way? Meanwhile I'll reach for one of these hand pumped beers which are a lot less bother …

… a penny drops!

Flippin' heck, it works too! But this will require some piccies and it is still morning so I'm not pouring beer yet. You'll have to wait for the description.

To be continued …

 

[HarryFlatters]

https://www.kegerators.com/beer-line-calculator/

Getting the right length of beer line should help, and I've Macgyvered a party tap to have about 6' of 3/16" diameter line in the middle of some standard 3/8" line which helps. Used a couple of JG reducers to attach all the parts and away I go. It's still a bit foamy, but much better than 18" of 3/8" line like I had before.

Nae clue about fermenting under pressure though, but have read a thread on here about fermenting in a corny and using a spunding valve attached to a ball lock connector. I quite fancy it as I love my German beers and a lot of them are made using natural carbonation like this (I believe you're not allowed to force carbonate under the Reinheitsgebot regulations).

 

[peebee]

https://www.kegerators.com/beer-line-calculator/ …

You're right. That's exactly what I was referring to when saying "I'm very unimpressed with … ".

I'll edit the OP to say "beer line calculator" instead of "kegging tables".

 

[HarryFlatters]

What is unimpressive about it? I don't really understand the issue without a bit more context.

 

[F00b4r]

Almost all online beer line calculators are American based, who describe beer line in the same terms but mean an entirely different size to UK beer line; the UK describes beer line by outer diameter of the tubing whilst Americans refer to the inner diameter. This makes a huge problem if using these calculators without being aware of this.

Dropping the pressure in the keg for serving is a hassle and also is not great for hoppy beers as you are essentially bleeding off all that “goodness” that you spent time, effort and money putting in.

I found the easiest way to get a great pour was to buy 100m of 3/16 line for about a tenner and then just start with what a calculator told me and then chop off a little more if it was too slow, you very quickly and cheaply get a really nice pour for different styles/pressures and treat the beer line as disposable so no cleaning either.

Moving on, and an entirely different subject. I'm keen on brewing low-alcohol beers and ferment in the dispensing keg, under pressure using "spunding" valves. I'm perfectly happy with the regulators I've repurposed as very accurate low-pressure "spunding" valves. But recently I was made aware of purpose built valves made (in China) for an Australian bunch called "Kegland". So I ordered a couple, they are called "Blowties", via AliExpress to play with. At the same time I noticed some plastic secondary regulators based on the same design as the "Blowtie", so I got a couple of them (they were only a couple of quid) to play with too. The description said "suitable for gas or liquid"; what on earth would you want a wet regulator for?

You can split your mains water, to a water carbonator and the reg to drop it to about 20 PSI to a handy ball lock post on your sink:

 

[phildo79]

Whenever I am happy with the carb levels (either through force carbing or priming), I turn off the gas when I am finished serving beer for the night. I do not turn it off after every pour, simply at the end of the night when I am not going to use it any more.

I do not think this makes a difference but I keep my gas and keg in the same fridge. I also use a flow control tap that is directly attached to the liquid out post. I have it set at fully opened and rarely need to adjust it. I pour at approx. 10 psi.

I cannot complain about the levels of foam as the majority of my pours are to my satisfaction. And a pour takes about 5 seconds. Again, not sure if this makes a difference but my glass of choice about 90% of the time is a snifter glass.

I was concerned about too much foam with using a tap directly attached to the liquid out post but I have nothing bad to say about the flow control tap. It has worked a treat so far and was well worth the money. I got it from Dark Farm as @Gareth Davies was selling it for much less than all the other popular online HB stores.

 

[peebee]

What is unimpressive about it? I don't really understand the issue without a bit more context.

You are being impatient! The OP did say "you'll have to wait … ".

But to colour-in a bit more before I can do piccies:

There is two ways of approaching pour times (without foam) for "kegged" beer. One to reduce pressure behind the beer at the tap by increasing the friction in the delivery pipes or by actually reducing the pressure in the keg. The other method is to reduce the flow of beer to the tap with a restriction. Increasing the length of delivery pipe to increase the friction is the most popular and the best. But it has to be tuned to work optimally, and that may mean changing the length of tube to alter friction with each new beer. Fine if you stick to a very limited range of pressures (maybe just one) but a bit of a pain if flirting with different beers, different serving pressures, etc. Releasing the pressure in the keg might be more versatile, but if you forget to restore the pressure after a session (or for particularly long sessions) the beer goes "flat". A restriction to reduce flow (with an in-line restrictor or else one on the tap itself) is a difficult approach because it doesn't actually reduce the pressure. The restriction may require constant fiddling to prevent volumes of foam or the pour dropping to a dribble.

The solution I'll describe uses the "wet" regulators I mentioned earlier. They might give the impression of reducing pressure, but are actually operating as a variable "restrictor". But they manage the restriction automatically. So once set, they function whatever the keg pressure, and (hopefully, time will tell) whatever the beer. Sort of "fit and forget".

The important thing is these "wet" regulators currently are only costing £2-3 and that is cheaper than several meters of beer line.

 

[Gareth Davies]

Whenever I am happy with the carb levels (either through force carbing or priming), I turn off the gas when I am finished serving beer for the night. I do not turn it off after every pour, simply at the end of the night when I am not going to use it any more.

I do not think this makes a difference but I keep my gas and keg in the same fridge. I also use a flow control tap that is directly attached to the liquid out post. I have it set at fully opened and rarely need to adjust it. I pour at approx. 10 psi.

I cannot complain about the levels of foam as the majority of my pours are to my satisfaction. And a pour takes about 5 seconds. Again, not sure if this makes a difference but my glass of choice about 90% of the time is a snifter glass.

I was concerned about too much foam with using a tap directly attached to the liquid out post but I have nothing bad to say about the flow control tap. It has worked a treat so far and was well worth the money. I got it from Dark Farm as @Gareth Davies was selling it for much less than all the other popular online HB stores.

Thanks for the big up!

 

[peebee]

Some photos! I'd received some "party taps" for this exercise because I knew how notoriously bad they were. I've got two taps with a short length of tube, with one connected to a "wet" regulator. It was a bit of a juggling act attaching these taps a getting a representative shot, but here's the first using just a tap and no regulator:

No surprises there. A glass of foam! This is set to about 12PSI in the keg. It's a rye malt pale ale, but it turned out a little bit dark for a "pale", but at 0.5% ABV it is quite remarkable to have any colour at all. So next with a "wet" regulator fitted inline:

I was a bit slow so the head has died back a little, but the difference compared to the first glass is quite marked. The pour is slower and it does take about 4x longer to fill the glass. But I know which I'd rather have.

I'll post photos of the tap arrangements used for the piccies tomorrow.

 

[foxbat]

@peebee are all your test pours at whatever your ambient temperature is? It does make a big difference if you've got the whole system at lager temperatures vs. ales. Guessing ale cellar temperature knowing your tastes?

 

[peebee]

@peebee are all your test pours at whatever your ambient temperature is? It does make a big difference if you've got the whole system at lager temperatures vs. ales. Guessing ale cellar temperature knowing your tastes?

Knowing my tastes? Can't be having that! Being unpredictable is a trait I've developed (unwillingly) quite recently. And so you're wrong! That "beer" is from a developing kegerator (another of my ongoing projects) and is at 6-7C.

I was serving a fully "leaded" beer with one of these "wet regulators" earlier, also at about 7C and 12psi ("5am Saint" clone and my favourite amongst DIYDog beers) and it was a bit trickier (or should I say "slower") to pour. I don't know yet if this is an overlooked "feature" of these wet regulators, or because I've overdone the crippling for these tests by choosing to use "party taps" (those taps really are naff!).

I have reinforced my commitment to these "wet regulators" by putting in an order for another four. The newer ones do have a winged adjuster (like in @F00b4r's piccie) so they can be tweaked more easily, but I'm still counting on them being a "fit and forget" solution and not needing tweaks.

 

[peebee]

The "apparatus" being used for these trials:

The inline regulator is easy to set up. The adjuster is just wound out until the flow stops, then slowly wound back in until the flow is right. It should only require adjusting once, but it might be (after I've had a bit more time with them) found necessary to tweak them a little each time? The new regulators come with "T-bar" adjusters which would make any such adjustments easy.

Remember what I said; as a "wet" regulator they are really working as a restrictor, or in gas terms, a flow control. This is because it doesn't control the pressure of the liquid; how can it because a liquid has no "pressure" because a liquid cannot be compressed. Gas pressure in the keg pushes the liquid (beer) through the pipe, so to control the pressure seen at the tap the pressure in the keg must be reduced and these devices obviously do not control the keg's pressure. As a consequence, when the tap is closed the liquid will start to apply the keg pressure on the tap, despite the "regulator" or the flow encountering friction (metres of tubing) or any other flow restriction. So when the tap is first opened there may be a brief spurt as if there is no control present (the beer may contain compressible gas bubbles). This is why I refer to them as "wet regulators": Do not confuse them with gas regulators, we're talking "hydraulics" now and that's quite different to gas pneumatics. It is why metres of tubing (to create friction) works so well, because the very gradually applied friction irons out the consequences of using a "restriction".

A further consequence of beer being forced through small apertures (such as the regulator's mechanism) or around tight corners, especially if small temperature changes too, the beer will "degas" to some extent so some foaming is bound to occur. If you have a habit of applying bone-crunching pressures and near cryogenic temperatures do not blame the tap for creating foam; look no further than your own actions.

 

[chrsherron]

http://www.mikesoltys.com/2012/09/17/determining-proper-hose-length-for-your-kegerator/
I like a bit of physics. I use this as I found my beer lines were too short and got alot of foam. Sorted it right out.

 

[peebee]

http://www.mikesoltys.com/2012/09/17/determining-proper-hose-length-for-your-kegerator/
I like a bit of physics. I use this as I found my beer lines were too short and got alot of foam. Sorted it right out.

I have stated this approach is about ideal, but the tuning of the calculated length does change with beer which I wanted to avoid (because the dispense system I use is fixed and can't easily change, but I will mess about with lots of different beers at different pressures). At least that guy on the link appears to have a well thought out equation; many "beer line length" calculators I've played with use a simplified linear equation that just about does. I came unstuck with these (along time ago!) trying to control pressured beer into a hand-pump before I "discovered" check valves ([sic], I should say demand valves). The common simplified calculators will lead you to think there is an achievable length of line that will stop the flow completely. Playing with those simple calculators led to a lot of beer on the floor!

But the grouse I still have with the calculator you've linked comes from the assumption "10 seconds is a perfect amount of time to pour a pint". What rubbish! I'm trying to stop glasses full of foam, not specify speed of pour. I might be having doubts about using these "wet" regulators on one fixed setting, but if I find they do require a bit of tweaking it's a very simple and empirical (i.e. done by feel, not calculator) thing to do. And a lot less "twitchy" than the flow controls built into some taps (and inline flow controllers).

 

[F00b4r]

Kegland also make these flow control disconnects. Although they are the people behind the very popular Intertap flow control taps they claim these with non-fc taps work better, especially if attached directly to the keg. Apparently it is all to do with being right at the head end and the entire reason they designed then this way, despite knowing it would cannibalise their FC taps.

Edit: they are not cheap by the time they get to the UK but you do get a SS disco too.

 

[Drunkula]

Inline flow regulators work even better with some 3/16" choker cable. It really lets you use the flow controller to fine tune as the choker line is doing the bulk of the resistance and it a less abrupt manner so you get even less foaming.

 

[peebee]

Inline flow regulators work even better with some 3/16" choker cable. It really lets you use the flow controller to fine tune as the choker line is doing the bulk of the resistance and it a less abrupt manner so you get even less foaming.

I like this idea. Mixing the advantages of using friction in the line ("choker line"), i.e. very gradual reduction of flow to limit breakout of gas from solution, combined with the convenience and practicality of a variable restrictor, that has less work to do and may not so easily trigger a breakout of gas from solution.

You can't cheat physics, but it is like finding a better ways of relocating china on to a china shop's floor than putting a bull in there.

I'll see how I get on with the regulators but keep this option in mind.

 

[-Bezza-]

As a slight hijack, does anyone have a video of what the pour from a balanced system should look like? I've followed the online calculators to get the right lengths and the result was just a pissy trickle coming out of the tap. Takes about 30 seconds to fill a pint glass. Would be good to have a reference point so I can see what the pour should look like roughly speaking, so I can trim the line accordingly.

 

[peebee]

As a slight hijack, …

It's not a "slight hijack", it's a good illustration of why these ideas of "balanced systems", "beer line calculators", "kegging tables", etc, etc, are such utter pox (in my opinion). It is the reason that I'm spending so much time trying to get a decent alternative system going. A system that just works, not one that just a handful can claim works for them.

 

[-Bezza-]

It's not a "slight hijack", it's a good illustration of why these ideas of "balanced systems", "beer line calculators", "kegging tables", etc, etc, are such utter pox (in my opinion). It is the reason that I'm spending so much time trying to get a decent alternative system going. A system that just works, not one that just a handful can claim works for them.

Well I'm thinking I'll just give it a bit of trial-and-error approach, and probably mostly do away with my 3/16" line and just use straight 3/8". At the end of the day, repeatedly filling glasses with beer "just to check the pour is right" is no bad thing!

Anyway, for what it's worth, not sure if you've seen this video which gives the non-calculator method of balancing lines. I might need to get some of those secondary regulators (to allow for different carbonation levels) and give it a go:



Edit: my taps pour nothing like the ones at the start of a video. Oh to have my beer come out at that rate!!