PSI required to dispense through jockey box?

[homebrewbeliever]

Hello HBT community! I am building a jockey box for my wedding so I can serve my homebrew, and I've got a couple issues that I'd sincerely appreciate some help with. This jockey box is a 3-tap box and uses a 6-pass cold plate to chill the beer (I'll be using jumpers to run each beer line through the cold plate twice, which is why I am using a 6-pass plate instead of a 3-pass plate). The beer will be in corny kegs and kept around room temperature under the serving table. From what I understand, by using a cold plate and passing each line through it twice, I should easily be able to achieve a serving temp of around 40*F, even with the beer kegs sitting at room temp. However, the real issue I am having concerns the PSI of the kegs. I'll be carbing the kegs in my kegerator at home, which sits at 40*F. As such, I'll carb the kegs over two weeks at around 11 PSI at 40*F, which gets my beer to a carbonation level that I like. After they carb, I plan on removing them from the kegerator and storing them down in our cellar for two or three weeks and then I'll be bring them to our wedding. I am wondering the following:

-Is my understanding accurate that I can carb like normal in my kegerator (as described above) and then move the kegs to the cellar for a few weeks and they'll be fine? After they carb, I will take them off of the CO2 but I believe they should stay pressurized... I've heard of people making belgians and other ageable beers in a keg where they do this and then let the carbed beer sit in a cellar to bulk age.
-What pressure should I put the kegs under when serving at room temp, and how long can I keep them at that pressure without overcarbing them?
-How can I reduce the likelihood of foaming issues? Or will they even be an issue?

I've never used, much less built, a jockey box before, so I would sincerely appreciate some tips and info from those who have experience with this (especially those that have used a cold plate). Many thanks in advance!!!

 

[JuanMoore]

Hello HBT community! I am building a jockey box for my wedding so I can serve my homebrew, and I've got a couple issues that I'd sincerely appreciate some help with. This jockey box is a 3-tap box and uses a 6-pass cold plate to chill the beer (I'll be using jumpers to run each beer line through the cold plate twice, which is why I am using a 6-pass plate instead of a 3-pass plate). The beer will be in corny kegs and kept around room temperature under the serving table. From what I understand, by using a cold plate and passing each line through it twice, I should easily be able to achieve a serving temp of around 40*F, even with the beer kegs sitting at room temp. However, the real issue I am having concerns the PSI of the kegs. I'll be carbing the kegs in my kegerator at home, which sits at 40*F. As such, I'll carb the kegs over two weeks at around 11 PSI at 40*F, which gets my beer to a carbonation level that I like. After they carb, I plan on removing them from the kegerator and storing them down in our cellar for two or three weeks and then I'll be bring them to our wedding. I am wondering the following:

-Is my understanding accurate that I can carb like normal in my kegerator (as described above) and then move the kegs to the cellar for a few weeks and they'll be fine? After they carb, I will take them off of the CO2 but I believe they should stay pressurized... I've heard of people making belgians and other ageable beers in a keg where they do this and then let the carbed beer sit in a cellar to bulk age.
-What pressure should I put the kegs under when serving at room temp, and how long can I keep them at that pressure without overcarbing them?
-How can I reduce the likelihood of foaming issues? Or will they even be an issue?

I've never used, much less built, a jockey box before, so I would sincerely appreciate some tips and info from those who have experience with this (especially those that have used a cold plate). Many thanks in advance!!!

You are correct that you can take your beer off pressure once carbed and then store at room temp. As long as you don't have any leaky kegs, they'll store just fine that way, and the carbonation level won't change at all.

The serving pressure for jockey boxes is often dependent on the jockey box, in particular the length the beer has to travel. Since they're typically only used very short term, like one afternoon, it's not critical to match the serving pressure to the equilibrium pressure of the carb level like it is with more permanent set-ups. I'd probably start somewhere around 15 psi and increase until you get a reasonable flow rate. For longer coils or larger plates you might end up over 40psi.

As far as preventing foaming, just make sure you keep up with the ice, try to make sure the shanks and faucets stay cold, and don't let it sit too long between pours.

 

[homebrewbeliever]

You are correct that you can take your beer off pressure once carbed and then store at room temp. As long as you don't have any leaky kegs, they'll store just fine that way, and the carbonation level won't change at all.

The serving pressure for jockey boxes is often dependent on the jockey box, in particular the length the beer has to travel. Since they're typically only used very short term, like one afternoon, it's not critical to match the serving pressure to the equilibrium pressure of the carb level like it is with more permanent set-ups. I'd probably start somewhere around 15 psi and increase until you get a reasonable flow rate. For longer coils or larger plates you might end up over 40psi.

As far as preventing foaming, just make sure you keep up with the ice, try to make sure the shanks and faucets stay cold, and don't let it sit too long between pours.

Thanks so much for the tips!!! I'm glad that it doesn't sound too difficult... However, the wedding is going to be three days long and I was hoping to use the jockey box the entire time. There will be people drinking constantly though, and I'm only using 5 gallon corny kegs, so we should run through the kegs quickly enough for overcarbing to not be an issue. One thing I'm wondering, however, is how quickly I'll run through the ice. Do you, or anyone else in the HBT community, have experience with how quickly cold plates melt ice? My jockey box isn't very large (in fact, I got the smallest profile one that would fit three taps and my cold plate). I've attached pics below:

 

[JuanMoore]

How quickly you go through ice is highly variable and will mostly depend on how warm the beer is and how much is passing through the plate. I hope your cooler has a drain on it. It's very important for the water to be constantly draining for the plate to work effectively.

 

[homebrewbeliever]

How quickly you go through ice is highly variable and will mostly depend on how warm the beer is and how much is passing through the plate. I hope your cooler has a drain on it. It's very important for the water to be constantly draining for the plate to work effectively.

I did install a drain, actually, however I put it about half-way up the back of the cooler. I plan on allowing the cold plate to sit in ice water, but to make sure to keep it packed tight with ice, allowing residual water to run off so it doesn't overflow. I have read that there is a huge debate about keeping the water completely drained, and many who have tried it both ways say there is no difference... I just keep thinking about how air is a very poor conductor and it seems that having a nice mix of near-freezing temp water (packed tight with ice) would actually work better (if not the same) as just having ice with all of the water drained.

 

[JuanMoore]

I did install a drain, actually, however I put it about half-way up the back of the cooler. I plan on allowing the cold plate to sit in ice water, but to make sure to keep it packed tight with ice, allowing residual water to run off so it doesn't overflow. I have read that there is a huge debate about keeping the water completely drained, and many who have tried it both ways say there is no difference... I just keep thinking about how air is a very poor conductor and it seems that having a nice mix of near-freezing temp water (packed tight with ice) would actually work better (if not the same) as just having ice with all of the water drained.

The problem is that when the plate is sitting completely submerged the water close to it gets much warmer, and actually insulates it against the ice and colder water above. You either need some way to circulate the water, or to let it drain so that there's some flow of water and air. The warmer the beer is the more critical this is. At 65 degrees ambient it might not make any difference. I know from my own experience that leaving the cold plate submerged in a thick ice water slurry when the beer is at 85 degrees at a picnic doesn't work well at all, but as soon the drain opens it works great.

On the other hand, if you have some way to constantly circulate/agitate the ice water slurry then it's actually much more efficient to keep it submerged.

 

[homebrewbeliever]

The problem is that when the plate is sitting completely submerged the water close to it gets much warmer, and actually insulates it against the ice and colder water above. You either need some way to circulate the water, or to let it drain so that there's some flow of water and air. The warmer the beer is the more critical this is. At 65 degrees ambient it might not make any difference. I know from my own experience that leaving the cold plate submerged in a thick ice water slurry when the beer is at 85 degrees at a picnic doesn't work well at all, but as soon the drain opens it works great.

On the other hand, if you have some way to constantly circulate/agitate the ice water slurry then it's actually much more efficient to keep it submerged.

Hmmm... okay, that makes sense. Well, I already installed the drain, so there's no going back there, so either I'll have to add a second drain, or I'll have to be sure to agitate the ice/water mixture on occasion.

 

[homebrewbeliever]

The problem is that when the plate is sitting completely submerged the water close to it gets much warmer, and actually insulates it against the ice and colder water above. You either need some way to circulate the water, or to let it drain so that there's some flow of water and air. The warmer the beer is the more critical this is. At 65 degrees ambient it might not make any difference. I know from my own experience that leaving the cold plate submerged in a thick ice water slurry when the beer is at 85 degrees at a picnic doesn't work well at all, but as soon the drain opens it works great.

On the other hand, if you have some way to constantly circulate/agitate the ice water slurry then it's actually much more efficient to keep it submerged.

Also, what I don't understand is why people say you don't need to drain the water if you are using stainless steel coils but you do need to drain the water if you are using a cold plate... It would seem that both would suffer from the issue of having the water directly around the coils or plate warm up. Any ideas?

 

[JuanMoore]

Also, what I don't understand is why people say you don't need to drain the water if you are using stainless steel coils but you do need to drain the water if you are using a cold plate... It would seem that both would suffer from the issue of having the water directly around the coils or plate warm up. Any ideas?

While the surface area of chilling component in contact with the beer may be the same, the cold plate has a much smaller surface area in contact with the ice/water than a coil does. The smaller that surface area is, the greater the insulating effect of the warmer water will be.

 

[30Bones]

I used a jockey box for the firs time in 20 years last weekend. It was a 2 pass, 2 tap unit I borrowed from a club member. I think my issue was not enough beers being served at my friends party. We didn't even finish the 2 kegs I brought that were roughly 75% full so I think that was part of my foaming issues. I was up into 20psi range and that only got worse and the pours were super slow due to the beer probably dang near freezing in the plate before the next beer was dispensed.

 

[homebrewbeliever]

While the surface area of chilling component in contact with the beer may be the same, the cold plate has a much smaller surface area in contact with the ice/water than a coil does. The smaller that surface area is, the greater the insulating effect of the warmer water will be.

Excellent point. I spent a bit of time this morning removing the drain, plugging the hole, and moving the drain to the bottom so the water will drain completely. Thanks so much for the tip Juan!

 

[homebrewbeliever]

I used a jockey box for the firs time in 20 years last weekend. It was a 2 pass, 2 tap unit I borrowed from a club member. I think my issue was not enough beers being served at my friends party. We didn't even finish the 2 kegs I brought that were roughly 75% full so I think that was part of my foaming issues. I was up into 20psi range and that only got worse and the pours were super slow due to the beer probably dang near freezing in the plate before the next beer was dispensed.

Just out of curiosity, what was the temp of the beer in the kegs when you ran it through the plate? And what is your estimation of how much time elapsed between pours?

 

[30Bones]

Kegs were at ~80* I would guess. I took them out of the fridge Saturday morning and took them to the party that night.

Between pours, over 5 minutes would be a safe assumption

 

[westo2]

Kegs were at ~80* I would guess. I took them out of the fridge Saturday morning and took them to the party that night.

Between pours, over 5 minutes would be a safe assumption

The kegs being at 80 deg was probably the root of your problem. Jockey boxes work well, but will struggle as the beer gets up in temperature. The CO2 saturation of the beer is far less at 80 deg than at 40 or even 60 degrees. The run from the keg through the plate or coils was likely not long enough for all that CO2 to go back into solution (i.e. - when the beer was at 80, the tap was pulled and the drop in pressure immediately caused much of the dissolved CO2 to come out of solution, the length of line where the beer was cold was not enough to overcome this - longer loops of line in the cooler may have helped, but at 80, still probably would not have been enough to adjust for the pressure drop).

My understanding is that Jockey Boxes are very effective on chilling beer that is up to 60-65 degrees or so, above that they start to reach their limitation. They simply can't balance the pressure and temperature differential between the keg at 80 and serving at 35.

When using mine, I keep them at fridge or basement temperature for as long as possible, and then keep them out of the sun and wrapped in a blanket or other insulation to avoid warming the beer too much.

As far as the pressure question - as stated above, this is going to be dependent on the construction of the jockey box. I usually end up in the 20 psi range and pouring well, occasionally have to step it up depending on the keg temperature. As the keg warms, the pressure will need to be dialed up to keep the proper amount of CO2 in solution.

If using the jockey box over multiple days, your pour control will be improved if you are able to cool the kegs overnight or when the box isn't in use.

 

[30Bones]

Thanks Westo, I will keep the kegs cooler if I ever borrow this one again or eventually build my own. I haven't used one since HS/college and we didn't care how our Old Milwaukee poured as long as we got

 

[homebrewbeliever]

The kegs being at 80 deg was probably the root of your problem. Jockey boxes work well, but will struggle as the beer gets up in temperature. The CO2 saturation of the beer is far less at 80 deg than at 40 or even 60 degrees. The run from the keg through the plate or coils was likely not long enough for all that CO2 to go back into solution (i.e. - when the beer was at 80, the tap was pulled and the drop in pressure immediately caused much of the dissolved CO2 to come out of solution, the length of line where the beer was cold was not enough to overcome this - longer loops of line in the cooler may have helped, but at 80, still probably would not have been enough to adjust for the pressure drop).

My understanding is that Jockey Boxes are very effective on chilling beer that is up to 60-65 degrees or so, above that they start to reach their limitation. They simply can't balance the pressure and temperature differential between the keg at 80 and serving at 35.

When using mine, I keep them at fridge or basement temperature for as long as possible, and then keep them out of the sun and wrapped in a blanket or other insulation to avoid warming the beer too much.

As far as the pressure question - as stated above, this is going to be dependent on the construction of the jockey box. I usually end up in the 20 psi range and pouring well, occasionally have to step it up depending on the keg temperature. As the keg warms, the pressure will need to be dialed up to keep the proper amount of CO2 in solution.

If using the jockey box over multiple days, your pour control will be improved if you are able to cool the kegs overnight or when the box isn't in use.

Very sound points. I am using jumpers on my cold plate to run each line through twice (i.e., three taps running through a 6 pass cold plate). I am expecting my kegs to get as warm as 75*F, but hopefully no warmer. I would think that running each line through twice using the jumpers would help dissolve the CO2 back in the beer so my foaming problems wont be an issue... what do you think?

 

[westo2]

I can't say from practice how that will work - I've only used mine with the kegs up to 60-65 degrees or so. My understanding is that you would need to add line length between the cold plate and the tap to add resistance to force CO2 back into solution once the beer is chilled.

Always worth a try. If you find that you are having foaming issues - another cheap and quick option is to grab a large rubbermaid tub and toss the kegs in that with some ice (or some water and icepacks). You wouldn't need to have the kegs fully covered in ice, as the dip tube will be pulling the coolest beer from the bottom. And you aren't needing to cool them to serving temperature, just knock them down from 75-80 to the 60 degree range. Another option to cool the kegs: http://www.homebrewing.org/KEGlove-and-ice-blanket-bundle-for-5-gallon-soda-keg_p_1131.html

A bit more discussion here: https://www.homebrewtalk.com/f35/jockey-box-questions-72433/

All that said, play with your pressures as you hook up - and you may be fine.

 

[homebrewbeliever]

I can't say from practice how that will work - I've only used mine with the kegs up to 60-65 degrees or so. My understanding is that you would need to add line length between the cold plate and the tap to add resistance to force CO2 back into solution once the beer is chilled.

Always worth a try. If you find that you are having foaming issues - another cheap and quick option is to grab a large rubbermaid tub and toss the kegs in that with some ice (or some water and icepacks). You wouldn't need to have the kegs fully covered in ice, as the dip tube will be pulling the coolest beer from the bottom. And you aren't needing to cool them to serving temperature, just knock them down from 75-80 to the 60 degree range. Another option to cool the kegs: http://www.homebrewing.org/KEGlove-and-ice-blanket-bundle-for-5-gallon-soda-keg_p_1131.html

A bit more discussion here: https://www.homebrewtalk.com/f35/jockey-box-questions-72433/

All that said, play with your pressures as you hook up - and you may be fine.

Thanks. I am hoping that using jumpers will double the line length. I think that there are 18' or so of piping in the cold plate for each pass, so then by having it run through the plate twice I am hoping that will be sufficient. We will see. I plan on testing it with some carbonated water... I know it wont be a perfect test d/t the difference in density, but it should hopefully give me a good idea of how this is going to work. If all else fails, I will definitely throw the kegs in a tub of some ice water.

 

[olie]

I realize this is an old thread, but search brought me here and I wanted to add a comment...

"How fast will the ice melt" is exactly in proportion to the temp of the beer going in, the temp of the beer coming out and the amount of beer that changes temp. There's no magic here, it's a simple heat transfer.

For our purposes, will ignore the tiny bit of heat loss through the walls of the cooler or out the metal parts that stick through (the taps & lines). I'll talk about an "ideal" system that doesn't leak heat, but the answer will be "close enough".

It takes 1 calorie to cool 1cc of water 1°C (1.8°F). It takes 1cal to warm 1cc of water or ice 1°C. So if you have 1cc of 20°C (68°F) water and you want it to be 3°C (37.5°F) water, you need to pull 17cal of energy off of it. If you have 1cc of -17°C (~2°F) ice and you pump 17cal of energy into it, you have 1cc of 0°C (32°F) ice.

Here's where the magic of ice comes in: it takes 80 calories to do the state change. That is, to go from 0°C ice to 0°C water requires 80 cal.

Let's say you have 4000ccs (4 L, about a gallon) of -17°C ice. Pushing 68,000 calories (4000x17) of energy into it will bring it to 0° -- just on the verge of melting -- ice. That's what would happen if you pushed 4000cc (~1 gallon) of room-temp beer through the line.

But now: magic! The next ~80 gallons of room-temp beer chills to ~3°C and imparts exactly the amount of energy needed to melt all that ice.

The tricky bit: you don't apply the heat evenly. Sometimes the lines are touching melting ice, sometimes the lines are touching cold/cool water, sometimes the lines are touching still-very-cold ice.

...And sometimes you toss-out a lot of cooling with the melted ice.

Somebody can check my math -- I probably goofed-up something in there -- but the general idea is correct.

Because of inefficiencies in the system (and throwing away perfectly good cold water!) I'd keep around 2-3x the calculated amount of ice. Remember, too, that a bag of ice has a lot of air in it. Block-ice works better for the math, but doesn't touch your beer lines as well.