Jockey Box

[johnsonbrew]

It's obviously been a while since this topic has been brought up so I have a little bit of experience to fill in the blanks. When I use my jockey box, I just get a block of ice and rest the cold plate on top and then surround to plate with ice. Over a 5 day camping trip I need to replace the ice once but just leave all the water. The first several pours are foamy but as the beet adjusts with the temp and settles, the pours get better after a bit. I would suppose you could set your co2 at a lower pressure and have slower pours to help eliminate the foam. I really hate waiting for beer to fill my cup before I drink it though.

 

[Malric]

In theory, the water would be warmer than ice. In practical application, I think the water would keep near freezing temperatures and act as a buffer.

 

[homebrewbeliever]

In theory, the water would be warmer than ice. In practical application, I think the water would keep near freezing temperatures and act as a buffer.

That is exactly what I was thinking. Even more, why would you not want to mix salt-water and pack it with ice to bring it to even lower temps? I would think this would work better than just ice and letting the water drain off, but I may be sorely mistaken...

 

[Malric]

You probably could, but I wouldn't add salt for corrosion concerns. I'm going to be using mine again this weekend. I'll try draining the water this time to see if there is any noticeable difference.

 

[krazydave]

Just to chime in, I built a two tap jockey box using a four pass cold plate. Each tap goes through two passes on the plate.
I too have read everywhere that the cold plate should be elevated and drain left open to keep it out of standing water.
Not once have I done that.
After a few days camping in 90+ degree weather and kegs sitting outside the whole time wrapped in a moving blanket, my box was full of 90% water and the plate was submerged in about 6-8". I can't honestly say that it ever performed any different being under water than it did with ice directly on it with no water. The beer was always cold and once I got the pressure right, foam never became an issue.

One thing I can say though is that I have to bump my keg psi up to about 20 to get a good pour. Over a week of sitting at that pressure, it does seem to over carb the beer if I have any left to bring home and put in my kegerator on shorter lines. So just something to keep in mind.

 

[Doongie]

If the water is allowed to drain, you will have ice contacting the plate at random locations, but much of the plate is NOT in contact with that ice, but air. The temperature change of water is MUCH slower than the temperature change of air, and any water in contact with the plate will chill the plate (and it's precious contents) better than if that space were air.

Also, bust up the ice if necessary, as it melts it can have a tendency to form large clumps, and draw away from the plate or coil, which can then not be in contact at all with your plate or coil. Then you have nearly zero chilling capacity unless there is water in the cooler.

When not in use it should be thoroughly cleaned and dried.

 

[homebrewbeliever]

Excellent! Thank you so much for the advice. I think I'll just not worry too much about any standing water then. I plan on getting one of those well-insulated 5-day coolers and just not worry about draining any water.

 

[westo2]

Just to chime in, I built a two tap jockey box using a four pass cold plate. Each tap goes through two passes on the plate.
I too have read everywhere that the cold plate should be elevated and drain left open to keep it out of standing water.
Not once have I done that.

I've never put much stock in the old 'never let the cold plate sit in contact with water' theory. It gets bandied about all the time, but never have I seen any science to back it up. It keeps getting repeated, but I've not been able to find an acceptable reason as to why.

The physics of the problem even seem to be quite the contrary - water is at it's densest just a bit over freezing at 4 deg C (~39F). This means that as the ice melts, the coldest water will then sink to the bottom, leaving the slightly warmer water in contact with the ice. Now - we are dealing with a very small scale, so the actual differences are probably negligible and thermal convection likely not significant.

However, as far as I can figure - as long as your ice/water mixture is kept at the serving temperature you want your beer at, the most efficient cooling will be with a mixture of ice and water as the water is a far more efficient cooling medium than just ice and air.

I've got a 3 tap jockey box with two cold plates -a single pass and a double pass. I've used it for hours on 80+ degree days with no issues without draining off the water. I do tend to set the pressure up to 20-25 psi to compensate for the temperature difference of the kegs, but even then I get a nice pour all day after the first glass or two from each line.