Any Soda Gun Users? Need Feedback On Setup.

[pidass]

so a few weeks ago I decided I wanted to add a soda gun to my existing kegerator. So after a few weeks browsing ebay I got everything I needed for a good price and pieced everything together.

Since the kegerator is in the garage I don't have access to a water line so instead I got 2 of my spare cornys filled them with water and let them carbonate in the fridge with the beer (35psi) with a carbonated water line (right now 1/4" but plan on swapping with 3/8") run to outside the fridge to the soda manifold. Right now I just have one flavor syrup hooked up (coke zero), the syrup does not get refrigerated, it sits right next to the soda gun manifold (syrup pump getting about 20psi).

So on button push to dispense the manifold combines the room temperature syrup with the refrigerated precarbonated water into my cup. So far its pretty good but not fountain quality, just not fizzy enough.

I'm not sure if the chilled carbed water hitting the little bit of room temp syrup is causing issues or if I need to up the psi on the water keg. Other threads I've seen said people are happy with 30-35psi. I also got larger tubing for the water to run from inside the fridge to the manifold, my thoughts were maybe the small tubing is too restrictive?

Anyone with a similar setup have any thoughts?

 

[Taz420NJ]

The tubing isn't restricting anything. The tubing from the manifold to the gun handle (inside the metal spiral) is only 1/8" ID. The manifolds usually come with 1/4" fittings because that's all you need. Having larger hose is only going to increase the volume of water that gets warm inside the portion of hose that's outside the fridge.

As far as the syrup, yes it "should" be chilled, but you can skip that if you increase the carbonation to compensate. A simple way considering you're low volume is to run 10' (or more if you can fit it) of the pressurized syrup hose inside the fridge. That will keep enough syrup for several glasses chilled, although it may not chill back down in time for seconds if you do several in a row (using stainless tubing like a jockey box coil or an actual cold plate will help it chill down faster). Even when chilled, diet syrups also tend to offgas the soda more than sugar syrups due to a reaction with the sweetener (similar to what causes the diet coke/mentos reaction)

Another thing you have to compensate for is that no matter what you do, the very first blast of soda and syrup will be room temperature - because the gun, manifold, and the hose between the manifold and the hole in the fridge is all warm. So you are starting with a few ounces of flat soda at the bottom - even if the glass is full of ice, because the warm soda water offgasses pretty much instantly as it comes out of the gun. I actually installed my gun/manifold/holster inside the fridge. This gets me around this whole issue, and I only had to drill one hole in the bottom of the fridge.

That said I would try putting an extra 5-10psi into the kegs to start. I can't really give you a recommendation, because I use a McCann carbonator (tank in the fridge, pump in the basement), and they require the CO2 to be at least 20-30psi above the incoming water pressure. Mine is currently set at 95psi.

 

[pidass]

thanks for replying, yea I'm trying to avoid making multiple more holes in the fridge, especially if I decide to add another flavor or 2 in the near future. I will try to up the psi on the water to see if that compensates for the temp difference. I did realize about the warm/flat for the exposed line on the first dispense, I got some pipe insulation to help with the subsequent dispenses but the first bit it not good.

So with your setup you have the carbonator in the basement and everything else in the fridge? How's the syrup/syrup pump do in the fridge? If not too much trouble do you have a pic?

Now you have me curious about putting a carbonator in the kitchen and running a line to the garage (or I guess running a new water line to garage and do everything there...hmmm...

 

[Taz420NJ]

No you misunderstood.. I have the gun/manifold in the fridge (keeps the gun/hoses cold to avoid the warm start), along with the tank from the carbonator (keeps about 1 1/2 gallons of seltzer cold). The carbonator's pump, the syrup pumps, the syrup box, and the CO2 tank are in the basement. There's about 30' of hose bundle between the fridge and the back end. In my setup there's only about 3' of syrup hose inside the fridge, but I raised the carbonator pressure to compensate. This is in my regular kitchen fridge, so I can't take up even more space with extra loops of hose - in a kegerator that wouldn't be an issue.

The syrup pumps themselves and the syrup bag aren't meant to be cold. They are supposed to stay room temperature and then get flash chilled right before it hits the gun/fountain. In a standard setup this is done by the cold plate - a large block of aluminum with fluid circuits running through it - in the ice bin. They are not as efficient in a refrigerator, and you can't put them in the freezer.. But as I said you can compensate for warm syrup by keeping the soda very cold and adding extra carbonation.

The carbonator pump is a bit loud, so if the whole thing is in the garage, just run a water line to the garage and install the pump there. You don't want to hear it in your kitchen.

I'll put some pics up later

 

[MrFoodScientist]

Even when chilled, diet syrups also tend to offgas the soda more than sugar syrups due to a reaction with the sweetener (similar to what causes the diet coke/mentos reaction)

I hate to contradict, but in my experience it's been the other way around. Regular soda has more sugar (dissolved solids) to knock CO2 out of solution than diet does. The mentos reaction works better with diet because it retains more CO2 upon opening than regular does, so there's more CO2 in the diet than the regular when the mentos go in.

I would second the rest of Taz's recommendations, though. Don't refrigerate the syrups, but if you can refrigerate the syrup lines, that will help. 30 to 35psi should be enough pressure, but what's the temperature of your kegerator set at? At the low end carbonation-wise, 40°F at 30psi should get you 4.3 volumes while 34°F at 35psi should yield about 5.5 volumes, so there's quite a range there depending on your temperature. (As per this). I'm not sure what the motorized carbonators are designed to yield in terms of volumes of CO2. I believe most fountains have their tanks at room temperature and are chilled through a cold plate, so the chart suggests 95psi at 72°F would yield about 6 volumes.

 

[Taz420NJ]

I hate to contradict, but in my experience it's been the other way around. Regular soda has more sugar (dissolved solids) to knock CO2 out of solution than diet does. The mentos reaction works better with diet because it retains more CO2 upon opening than regular does, so there's more CO2 in the diet than the regular when the mentos go in.

Mythbusters tested the diet coke/mentos effect, and part of their testing involved adding raw ingredients from diet coke into bottles of seltzer. The largest reaction - pretty much equaling the actual nucleation reaction - was from the aspartame

I would second the rest of Taz's recommendations, though. Don't refrigerate the syrups, but if you can refrigerate the syrup lines, that will help. 30 to 35psi should be enough pressure, but what's the temperature of your kegerator set at? At the low end carbonation-wise, 40°F at 30psi should get you 4.3 volumes while 34°F at 35psi should yield about 5.5 volumes, so there's quite a range there depending on your temperature. (As per this). I'm not sure what the motorized carbonators are designed to yield in terms of volumes of CO2. I believe most fountains have their tanks at room temperature and are chilled through a cold plate, so the chart suggests 95psi at 72°F would yield about 6 volumes.

That's exactly how they chill.. However my system takes line temp water (appx 60F) and pumps it into the cold (37F) tank with the 95psi CO2. So according to that chart, assuming the water drops a few degrees upon mixing with the cold water already in the tank, it starts with about 8.0 volumes and gets up to about 11.4 volumes as it chills down. What comes out of my gun '"feels" virtually identical to what comes out of a regular fountain as far as bubbliness and bite, although I have the brix set slightly light. I set it by taste, not by cup measurement, and I prefer it with a touch less syrup.

 

[Taz420NJ]

Here's the pics of my setup so far.. The water circuit isn't hooked up yet, picked up the wrong fittings and haven't had a chance to exchange them. I also only have the one syrup so far (Diet Coke), but I have the three pumps (actually have six, but I realized I'll never have room for that many hoses in the fridge), so I will eventually get more. Only the one is actually hooked up yet because otherwise they'll just pump endlessly and waste the CO2. I'd really like to get diet A&W Cream, but I can't find it anywhere. I also want to try making my own syrup at some point.