Cold crash with the Fermzilla.

[Pale Man]

I'm about to use my Fermzilla for the first time for pressure fermenting, for those that use one or similar, what is the technique for cold crashing?

Just do it as normal? Im wondering because its under pressure will it suck the walls in or oxygen in as the beer reduces in temperature?

Do you give it a blast of CO2 beforehand. 

Cheers.

[Red devil 44]

5 minutes ago, Pale Man said:

I'm about to use my Fermzilla for the first time for pressure fermenting, for those that use one or similar, what is the technique for cold crashing?

Just do it as normal? Im wondering because its under pressure will it suck the walls in or oxygen in as the beer reduces in temperature?

Do you give it a blast of CO2 beforehand. 

Cheers.

I just CC with what CO2 is in it, I reduce mine in temp by about 3-4 degrees per day so usually it’s in CC for 6-7 days before I get home on break. 
‘The CO2 level will drop as you CC, but usually leaves around 5 PSI in there when I get to it.

‘Never had any issues with walls sucking in, I’ve pressure fermented probably 20 times in my Fermzilla, no issues. 

[Pale Man]

4 minutes ago, Red devil 44 said:

Never had any issues with walls sucking in,

Cheers for that, yeah i suppose that was pretty dramatic. My thoughts being when beer is cold crashed it contracts and with a normal fermenter sucks in oxygen, i was wondering what happens with a sealed unit. 

[kmar92]

@Pale Man most of my brews are pressure fermented and although I now use a SS fermenter I have used a Fermzilla in the past. I just cold crash as usual and although the pressure does drop as CO2 is absorbed into the beer I still usually end up with pressure still in the fermenter at the end of the cold crash. I usually have at least 5psi but usually more pressure so I do not think that you will have problems with the Fermzilla sucking in, I didn't have any such problems when using a Fermzilla.

[ozdevil]

i have never had issues with fermzilla  sucking in  when pressure ferment   and i usually  pressure ferment around 10-12 psi 
and cold crashing straight down hasnt effected  the suck in effect

i think if you have a leak   somewhere  you may get the suck back 

[Shamus O'Sean]

2 hours ago, Pale Man said:

I'm about to use my Fermzilla for the first time for pressure fermenting, for those that use one or similar, what is the technique for cold crashing?

Just do it as normal? Im wondering because its under pressure will it suck the walls in or oxygen in as the beer reduces in temperature?

Do you give it a blast of CO2 beforehand. 

Cheers.

I use a pair of 20 litre Fermeter King Juniors from Keg King.  If they start cold crash below 5 psi, the sides of the FVs contract in a little bit. I just push them back out with a little CO2.  If you get them to around 15psi before cold crashing, they should be fine. 

The first time I used them, I had their gas outs going into a jug of sanitiser. (Eewe alert) When I cold crashed them, it sucked sanitiser back into the FVs.  Final beer tasted fine though. 

Now, before cold crashing, I just disconnect whatever blow off arrangement I have. Most of the time I have dry hopped or added finings and so lost most of the pressure built up during fermentation anyway.

[Pale Man]

1 hour ago, Shamus O'Sean said:

The first time I used them, I had their gas outs going into a jug of sanitiser. (Eewe alert) When I cold crashed them, it sucked sanitiser back into the FVs.  Final beer tasted fine though. 

 

I'm using a spunding valve which i thought would be one way and not able to suck anything past tap handle ( i think without looking at it )

But will definitely keep that on board with disconnecting the gas out line before CC.

[ozdevil]

2 hours ago, Pale Man said:

I'm using a spunding valve which i thought would be one way and not able to suck anything past tap handle ( i think without looking at it )

But will definitely keep that on board with disconnecting the gas out line before CC.

the spunding valve should only work in 1 direction  and if it is one of the kegland spunding valves it will have and arrow pointing in the direction of flow