Spunding

[sdixon]

So I have read the posts about spunding and looked at the posted links, but I'm not clear about all the details. Is there any chance that someone could post some detailed pics and describe the steps? So here are some of the ambiguities for me:
1. Do you fill 2 kegs half way or one to the top?
2. If 2 kegs, do you have a spunding valve on each?
3. Do you have a line connecting the 2 kegs to balance pressure?
4. What post does the spunding valve go on?
5. If you have beer in 2 kegs you must rack into a third when finished, yes?
6. To rack, do you connect 2 beer out posts and push gas through gas in post?

Many thanks in advance.

[Chris Craig]

+1

[JohnQ]

So I have read the posts about spunding and looked at the posted links, but I'm not clear about all the details. Is there any chance that someone could post some detailed pics and describe the steps? So here are some of the ambiguities for me:
1. Do you fill 2 kegs half way or one to the top?
2. If 2 kegs, do you have a spunding valve on each?
3. Do you have a line connecting the 2 kegs to balance pressure?
4. What post does the spunding valve go on?
5. If you have beer in 2 kegs you must rack into a third when finished, yes?
6. To rack, do you connect 2 beer out posts and push gas through gas in post?

1. One Keg Filled to 4.25-4.5 gallons, you have to do either smaller batches, or lose some beer to the ferment.  In that case, I have used a 2nd keg in line to catch the krausen and protect the valve.
2/3. The 2 keg system has a line running from the gas post of the ferment keg to the liquid port on the 2nd keg, then the spunding valve on the 2nd keg to relieve the pressure.
4. If only using a single keg it's on the gas post of the ferment keg, if using a second keg to capture krausen, on the gas post of the capture keg.
5. N/A
6. Yes, the process is...
>Sanitize the serving keg and pressurize it to whatever pressure is currently in the ferment keg minus a pound or two.
>Attach spunding valve to the gas post of the serving keg.  
>Attach a tap or open ended line to the liquid post of the ferment keg and drain off a cup or two of the trub from the bottom of fement keg, hopefully it clears up.
>Attach a line between the liquid post of the ferment keg and the liquid line of the serving keg. Beer should start flowing very slowly.  The slower the better. If beer doesn't start to flow, then back off on spunding valve a bit to create a pressure differential.
>Attach gas to in post of ferment keg from your co2 tank, and slowly increase pressure to maintain the flow of the beer from ferment keg to serving keg.  Slower is better.  You should hit the point where the in pressure from the regulator=the spunding valve release pressure, and you're transferring at the same pressure, keeping the natural carb in the beer while releasing the CO2 that was in the serving keg as it it replaced by the beer.
>As soon as you get to the bottom of the ferment keg, disconnect the transfer line, before it starts moving the balance of the trub across.

2 kegs to ferment has been done by fakr, when he brewed too much, he can advise on the variant that he developed to cope with that.  It could be done for 9 gallon batches, and then you'd need different connectors, or just run this system twice.

There is also a way to use other inline capture devices for the krausen instead of a second keg...fakr made up a PET bottle with an in and out that looked pretty cool, but since I have a rediculous number of kegs, I find that easier.

JQ

[Kyle]

Not sure when my camera is at the moment, but this should help:

1. You can go the 2 keg route, but I prefer to just scale my batch size down to 4.25 US gallons

2. You would connect your keg(s), if using multiple to a manifold and have the spunding valve on that (i.e: manifold connections = line from gas post on keg 1, line from gas port on keg 2, pressure guage, spunding valve)

3. When I transfer fom the fermenting keg to the serving keg, I first pressurize the fermenting keg to 30 psi, then the serving keg to 29psi. Then I hook up a line from the liquid out of the first keg to the gas in of the second. It is helpful to also have a wye in that line so you can put a picnic tap in there to drain off the yeasty goo that comes right at the beginning. Then I close the picnic tap and put the gas portion of the line on the empty keg. As the beer falls through the C02 in the 2nd keg, it will quickly increase the carbonation (I spund at 6psi the whole time, so it needs a boost from the force carb method). Then I gently pull the pressure release valve on the serving keg and let it fill, it takes about 15 minutes to do or you will have a foam explosion if you rush.

4. Gas out, otherwise, the pressure will empty your beer out all over the place

5. Yep

6. See #3

[fakr]

Hey Steve!

Well, it looks like everyone has their own little techniques for spunding, pretty neat to read actually.

Here is a pic of 2 kegs attached to the same spunding valve, through a silly krausen catcher I made.  To be honest though, it would probably be much easier using a third keg like JohnQ mentioned.
[attachment=0:zhjgaulb]setup.JPG[/attachment:zhjgaulb]
The batch I made in the kegs in the pic was from a 30L boil, so they weren't quite full.  You'll see both kegs are attached via the gas ports into a gas manifold I got at princess auto.

With the little blue manifold you see in the pic, the kegs end up equalizing eachother, which is fine when fermenting the same batches of beer in both, but I've since added a small check valve at the end of the gas fittings so co2 is only allowed out and not back in the keg.  This way I can brew 2 different styles without worrying about cross contamination.
Only problem with having a check valves is that the spunding valve will only read the keg with the highest pressure.  No big deal during a 6psi fermentation, but not good for naturally carbonating.

To naturally carbonate, simply turn the pressure way up on the spunding valve during the last half day of fermentation.  The pressure should rise up to 24-26 psi.  If it doesn't, remove the gas fittings, shake the kegs, and reattach the fittings....pressure should rise over a half day period.  Once it reaches 24-26psi, put in fridge and cold crash for 24 hours.

I use the same method as the others to transfer to the secondary for serving.  make sure you purge your second keg of any oxygen, and replace with CO2, keeping the pressure a pound or two below the primary.  you can check the pressure with yoru spunding valve gauge.  

Transfer nice and slow, and when it's done, you can literally connect it to the tap and drink fresh carbonated beer!  its great!

[sdixon]

Thanks for this guys!

What is the parts list to build a spunding valve?

[JohnQ]

I've got 3 under construction right now, do you have any threaded grey co2 connectors?  If so then I can do the whole thing for you for $40.  If you don't have one, you'd have to wait for my order from Simgo to get here with some more and it would be $45.
Otherwise there's a price list on here somewhere if you search my username and spunding it will be one of the older posts.

JQ

[sdixon]

JQ - No I don't have a Grey CO2 disconnect and yes I would be interested in one for $45 please

[brew]

I should remember this from Saturday, but I've forgotten... how do you know when its time to crank the spunding valve up to 20-30 psi to carb yer beer?

[Kyle]

you can wait until the loud hissing is just a faint, barely audible one and then go for it. Alternatively, you can do what I do, which is simpler, and just leave it at 6psi til done, then force carb the rest of the way in the serving keg (1 day in the fridge at 30psi)

[JohnQ]

I use my refractometer and check the SG regularly, when you get about 5 points from your target finish point, then close it down.
Kyle will eventually see the light...again... :ugeek:
JQ

[brew]

Ah yes - cool thanks guys...

[WJShaw]

In regards to cranking down the spunding valve to increase the carbonation.

The fermentation has slowed down now and I've cranked down the valve but the low volume hissing is still audible. The max psi right now is ~14 psi. Is this normal? The only reason I ask is when I removed the spunding valve for ~3 hours and the psi went to 25.

Anyone have the ability to clarify?

[WJShaw]

In regards to cranking down the spunding valve to increase the carbonation.

The fermentation has slowed down now and I've cranked down the valve but the low volume hissing is still audible. The max psi right now is ~14 psi. Is this normal? The only reason I ask is when I removed the spunding valve for ~3 hours and the psi went to 25.

Anyone have the ability to clarify?

All fixed. Did a soap test and found a leak.

[Kyle]

I use my refractometer and check the SG regularly, when you get about 5 points from your target finish point, then close it down.
Kyle will eventually see the light...again... :ugeek:
JQ

yes... 4 days from grain to glass fully carbed, on tap and delicious. Natural carbing is quite nice actually.