Closed top fermenter

[doctorcosmonaut]

With a closed top steel fermenter do you put the N2 in before or after you have fermented?

 

[salcoco]

After fermentation. CO2 will protect the wine while fermenting.

 

[doctorcosmonaut]

After fermentation. CO2 will protect the wine while fermenting.

So the yeast can survive in a CO2 environment, but not one of nitrogen?

 

[jamesngalveston]

whats n2 anyhow...i thought the yeast needs o2 in primary..if its closed how does it get that.

 

[doctorcosmonaut]

The "closed tank" is a style of steel fermenter. It still has an airlock.

N2 = Nitrogen. It is an inert gas.

Side question: What pressure should the co2 be put in the tank at? For N2 I read that you want to regulate it at around ~0.5 psi in a closed top steel fermenter (for safety?)... Would that then be the psi you'd want for co2 or is it different?

 

[salcoco]

the CO2 will occur naturally as the must or juice ferments. No need to add any additional during fermentation. CO2 post fermentation will be absorbed by the wine making it gassy, an undesirable wine. Post fermentation you would want to reduce the CO2 in the wine.
N2 is normally used to protect the wine after fermentation. However some would argue that the physics of gas laws dictate that not all of the oxygen is purged when N2 is added to top off a wine. Oxygen post fermentation is a bacteria carrier so purges are required.
What specifically are you trying to accomplish?

 

[doctorcosmonaut]

the CO2 will occur naturally as the must or juice ferments. No need to add any additional during fermentation. CO2 post fermentation will be absorbed by the wine making it gassy, an undesirable wine. Post fermentation you would want to reduce the CO2 in the wine.
N2 is normally used to protect the wine after fermentation. However some would argue that the physics of gas laws dictate that not all of the oxygen is purged when N2 is added to top off a wine. Oxygen post fermentation is a bacteria carrier so purges are required.
What specifically are you trying to accomplish?

Actually working on cider. I know cider production is significantly more similar to wine production than beer. So I'm trying to approach it as if it is wine. However, I don't mind natural carbonation... If that changes things with whether to use CO2 or not?

 

[DoctorCAD]

Since air is already 78% N2, does it really help to add more of it to a fermentation tank?

 

[sour_grapes]

Since air is already 78% N2, does it really help to add more of it to a fermentation tank?

Its not about adding the N2, it is about removing the O2.

 

[salcoco]

CO2 for force carbonation is an entirely different discussion. I am assuming you are just trying to protect the cider from contamination. Simply add the N2 to the closed vessel using a T at the end of the tube so that the gas is dispersed parallel to the top of liquid. Run for a few minutes and reseal the fermenter. If using a airlock, if over pressure the airlock will release any excess N2. no need to keep a constant pressure although that is your call, a low level psi should work, but you will be venting most back out of fermenter through airlock. I would just cell the fermenter without airlock once N2 is added.