For those who purge with fermentation

[Joejkd82]

How are you sealing your kegs? Usually some pressure is necessary.

My FV can't handle pressure so do you just hit with some gas to seal, vent it then hook up the FV?

Do you do it at pitching or do you wait for fermentation to begin?

If you spund, is 2 to 3 days of fermentation enough to purge the keg? The math I've seen is generally for a full ferment.

When/how do you add dry hops?

 

[greywolf]

I give it a blast of co2 to seal , set the spund to 5 or so and left er rip. Turn up the pressure in a week or so. I let it go the whole time. (I'm sure that the gas produced in a few days is enough, but, what am I gonna do with the rest of it? ) I never really understood only spunding for the last few days. I know it works, just don't get it.
I dry hop when I add the yeast or I'll vent it and quickly crack the lid and drop them in and reseal. Both ways work.

 

[day_trippr]

I'm not sure of the question now given the above response.

I purged my first pair of 5g cornelius-style kegs using fermentation CO2 a few weeks ago. The output of a pair of carboys was teed together with the line then connecting to the first keg's Out post, that keg's In post then connected to the 2nd keg's Out post, and finally the 2nd keg's In post was run to a 2L soda bottle half-filled with water, mostly as an observation mechanism, but also to keep the system quasi-closed.

The system pressure thus was dictated by how deep that last section of tubing was submerged. I started with it a couple of inches deep, which a SWAG says would be under 1/10th psi. That doesn't come within a couple of orders of magnitude of "sealing pressure" for a dodgy keg lid, but even for a such inflicted keg the leak likely wouldn't affect the purging process as the preferential path will be via the post ports anyway, and I expect one could simply take the keg off the purge line and pressurize it with external CO2. It might not be the most efficient, but it's WAY better than trying to purge with bottled CO2.

In any case, as all of my kegs will seal tight without pressure, when the fermentation slowed I just disconnected the kegs and tagged them as good to go. When the batch was ready for racking it saved me a good half hour of Star San purging...

Cheers!

 

[garzlok]

I just purged my first keg with CO2 produced from fermentation last night. I applied no added pressure and the CO2 from the ferment was able to push out the StarSan from the keg in about 2.5 hours.

I started the purge about 15 hours after active fermentation started. (I wanted to make certain I wasn’t blowing chunks at high krausen) I’ll be honest...I’m pretty amazed at how fast the purge went and how much CO2 is produced during fermentation.

 

[ChiknNutz]

I recently picked up a kegmenter that allows for pressure. Like some others have noted, I haven't found the need to first pressurize the keg to seal it, but they are brand new kegs only used a couple times now. For purging, connect the gas line of the fermenter to the liquid line of the keg, then attach spunding valve to gas line of keg. I've done this a few times now, have a batch fermenting now. The last couple batches, I spund at low pressure, less than 5 psi. After 3 days I then transfer wort to keg and of course disconnect fermenter. To naturally carbonate, I then crank up the spunding valve to desired carbonation level and leave for a week or so until fermentation is complete.

...I dry hop when I add the yeast or I'll vent it and quickly crack the lid and drop them in and reseal. Both ways work.

Interesting, I made a new thread about dry hopping right after pitching the yeast and only had a few replies so far. I have been wondering about this and would like to do this to avoid oxygen ingress.