Fermenting Under Pressure

[mtb]

I think I need to get bigger kegmenters...

FTFY

 

[Gloveski]

I

Maybe I'm missing something.. how is the temperature relevant to transfer speed?
Elaborate on your transfer method. I pressure transferred into two kegs today, each took ~10min but I could've loosened the spunding valve to get it done quicker

I attached co2 to fermenter at about 15 psi
And pressurised receiving keg to about 12 then adjusted spunding valve on receiving keg until it started hissing . It seemed to stall at times and I had to keep upping pressure on kegmenter to get it to continue transferring

 

[Gloveski]

Took about 45 minutes

 

[Lionman]

FTFY

Pretty much. There are 30L commercial kegs for sale in Perth on gumtree for $30. Considering converting some to kegmenters by cutting off the commercial disconnect and replacing it with a 4" tri clover ferrule. Have to go and see some steel fabrication places and get a quote for the cutting/welding. Should be able to build a 30L kegmenter for under $100 worth of parts. The welding might cost a bit though.

 

[mtb]

I


I attached co2 to fermenter at about 15 psi
And pressurised receiving keg to about 12 then adjusted spunding valve on receiving keg until it started hissing . It seemed to stall at times and I had to keep upping pressure on kegmenter to get it to continue transferring

I'd say that's due to the spunding valve being a little inconsistent. I have the same problem, the spring mechanism isn't the best, I have the model sold by KegKing. Be prepared to adjust the valve throughout the transfer - but also, if you've adequately purged your receiving keg with CO2, transferring fast shouldn't cause excessive foam. That's my experience anyway.

 

[Lionman]

I dont bother with a spunding valve for transfer. I attach the keg jumper, vent the kegmenter, attach gas and set pressure to 5 or so PSI. I use a fully purged receiving keg and just lock the PRV open.

Little bit of foam comes through towards the end of the transfer, not much though. I just close the prv when actual liquid come out the prv through or when gas is drawn from the kegmenter.

I do this outside and it's easy to just give the keg a hose down afterwards.

 

[Dave70]

(Reaches for wallet…)

Yep, one of those 'please explain' statement months for me..

Whos this Keg King?
Whats a spunding valve?
Whos Hoppy days?
Whats Clever Brewing?

Aaaand so on...

 

[Gloveski]

Just transferred another one took about 15 minutes this time . Happy days

 

[Crusty]

I'm not really happy with my first ferment under pressure due to pouring foam all the time.
The beer is pretty good & I'm almost certain that the process does as everyone says like reduced esters, phenols & you can certainly drink the beer so much quicker than you normally would following standard fermenting procedures.
For some reason though, I cannot balance my system with this keg & continually pour foamy beers.
I naturally carbed mine for 48hrs @26psi & for the life of me, I can;t get the bastard balanced.

 

[razz]

I'm not really happy with my first ferment under pressure due to pouring foam all the time.
The beer is pretty good & I'm almost certain that the process does as everyone says like reduced esters, phenols & you can certainly drink the beer so much quicker than you normally would following standard fermenting procedures.
For some reason though, I cannot balance my system with this keg & continually pour foamy beers.
I naturally carbed mine for 48hrs @26psi & for the life of me, I can;t get the bastard balanced.

What pressure do you keep your system balanced at Crusty?

 

[razz]

Ok. I have now kegged my first batch after 10 days. The ferment went along just fine and I have been cold conditioning the kegmenter for the last 2 days. A couple of things that came up worth noting.
1. I lost more to the kegmenter than I did with a conical, not much, about three litres of yeast beer slurry compared to 1-1 1/2 litres. I can allow for that in the next brew.
2. I had the temp sensor sitting in a 3 litre jug of water, compared to inserted in the conical. So my ferment temp was most likely a few degrees higher. Given that, the flavour after kegging is pretty bloody good.
3. I ran the beer through a 1 micron filter and this took about 15-20 mins per keg (as per Gloveski's experiences)
4. Carbonation was lower than I expected (on kegging) but given the variance in fermentation temp I think that accounts for less carb. (The temp sensor said 2 degrees with 75 kpa on the keg, but the temp in the keg may have been a bit higher)
5. **** all yeast bits in the filter. But you get that with very cold green beer.
So, anywho, pretty wrapped with how this turned out. I want to do an IPA in the next few days so I can make a few adjustments based on my first brew. If that goes okay then I will stick with pressure fermenting.
Anyone want to buy a 46 litre conical?

 

[Coldspace]

I'm not really happy with my first ferment under pressure due to pouring foam all the time.
The beer is pretty good & I'm almost certain that the process does as everyone says like reduced esters, phenols & you can certainly drink the beer so much quicker than you normally would following standard fermenting procedures.
For some reason though, I cannot balance my system with this keg & continually pour foamy beers.
I naturally carbed mine for 48hrs @26psi & for the life of me, I can;t get the bastard balanced.

Hey mate,
What was the temp when it was stable for 2 days at 26psi.?
What type of beer.?

I have found that I was getting foamy beers at the start if,
I rushed the end and it may still have over carbed before cc.
Really high wheat ales or reds/stouts etc etc, deff need lower psi at the end. Try aim for 19-21 max at 19-20 degrees.
Lagers , 26 max at 20 for the final rest. But if still foamy and over carbed then next batch finish lower like 23-24 psi. I am aiming mine to 24 psi finish now, and adjust up if needed next time for the receipe.

I have found I prefer to finish slightly under carbed then allow when at cc temps to either add a burst of gas, or when on tap leave at pouring pressure for cuppla days to steady out.

One theory I have is the smaller carb bubbles allow much more foam to develop . Others with more experience can add to this one, just my observations .

I have had several over carbed ferments in the first 6-8 batches but everything ATM seems to be working good for me.

Also, if your beer is not cold enough it may be allowing the co2 to come out of solution faster at pour causing foaming, I dispense mine at 0- 1 degrees with no issue through a chilled flooded font.
If your font or taps are warmer especially in the warm weather ATM this could be an issue. But I suspect it's over carbed. Depressurise the keg abit over the next several days to take out some co2. Or if you can lift the keg, take out of fridge, leave for 3 hrs to warm alittle, purge off head pressure, re-chill and should be good a day or 2 later.

If you dispense you beers warmer than mine, then you may on your next pressure ferment deff drop the finished pressures back and leave stable for 3 days before cc. So they are lower carb.

Cheers

 

[Crusty]

Thanks guys.
Stable for 48hrs @18deg & used a carbonation chart to get me around 2.5vol/Co2.
Dropped to 2 deg after that & disconnecting the spundy. Serving the beer now at 2deg but just can;t seem to hit the right serving pressure. I'm just using a beer gun that stays cold inside the fridge. I think I'm over carbed so I'll have to look at that next time. It's a Lager & when the foam dies down, it's pretty good.

 

[Coldspace]

18 degrees at 26 psi, prob slightly over carbed, mine finish at 21 degrees and 25-26 psi and it's been better.

It doesn't seem to take much between to little and too much with these brewing techniques , I've settled now on going slightly less, then allowing alittle adjustment on the finished product in my serving keg with my gas bottle.

Also, one thing that can cause diff things is if you have a bigger headspace or diff headspace at the higher pressure of warm finish before cc, the beer will absorb more co2, I've used my 50 ltr kegmenter with only 35 ltr batch and it was way over carbed to the same batch at 45 ltrs, one thing to keep in mind.

Have fun, it's a great way to brew once you get to know your system.

 

[Dave70]

This topic needs a sticky "Guide to fermenting under pressure" version to go with the other popular and informative 'Guide to' series.

 

[pcqypcqy]

How much line on your gun?

Evens though it stays cold you still need to have a decent length to slow the beer down.

Thanks guys.
Stable for 48hrs @18deg & used a carbonation chart to get me around 2.5vol/Co2.
Dropped to 2 deg after that & disconnecting the spundy. Serving the beer now at 2deg but just can;t seem to hit the right serving pressure. I'm just using a beer gun that stays cold inside the fridge. I think I'm over carbed so I'll have to look at that next time. It's a Lager & when the foam dies down, it's pretty good.

 

[Crusty]

How much line on your gun?

Evens though it stays cold you still need to have a decent length to slow the beer down.

Enough to know it pours perfectly fine when force carbing a keg at 300kpa for 24hrs.

 

[wide eyed and legless]

I have been following this thread and have bought all the bits and pieces to make a couple of Ghetto pressurised fermenter's, but last night came across this. https://www.brewshop.co.nz/blog/fermenting-under-pressure/
Which in turn led me to this. http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1984.tb04242.x/pdf
Will still go ahead and make my PF's to make my lagers but what is the step by step method of fermenting ales you guys are using, are you harvesting the co2 and putting it back in towards the end of fermentation?

 

[Dave70]

Any of you guys harvesting yeast, if you indeed can, from the blow off, or pitching straight back onto the cake?
Or does the whole process knock them around to much for another few rounds.

 

[mtb]

Any of you guys harvesting yeast, if you indeed can, from the blow off, or pitching straight back onto the cake?
Or does the whole process knock them around to much for another few rounds.

I've read plenty online to suggest pitching onto a yeast cake is bad news. Great writeup but it was on another forum so I won't link here, but search and you'll probably find. It's an overpitch risk apparently.

I harvest yeast from my kegmenters. After an extensive cold crash I chuck on a pluto gun and dispense ~500mL into a flask, after this much it usually runs clear (yeast strain dependent), then I pressure transfer to keg. Plenty of yeast left in the kegmenter.