First Keg Ferment

[theredviper]

I recently got a kegerator and decided to try my first keg ferment. I wanted to ferment and serve in the same one, so built a spunding valve to try and monitor pressure.

So far I'm ~72 hours in and there's no pressure built up. How long should this take? Should I have started with a blowoff tube instead or does that matter? There could be a leak too, I didn't pressure test my spunding valve. Rookie mistake!

I'm probably going to crack it soon to verify the yeast is going. It was proofed prior to pitching so I'm confused as to what the issue could be, or I just need to keep waiting.

I used fermcap S for the first time to reduce krausen too.

 

[odie]

I often find that the big lid oring will not seat without a pressure blast. I've had ferments bubbling out the lid oring until enough pressure built.

If an ale, yes, I think blow off tube first.

I don't use fermcap or anything like that

 

[theredviper]

Safe to give it a CO2 blast now? Just to like 10 psi?

 

[FromZwolle]

Safe to give it a CO2 blast now? Just to like 10 psi?

i'd give it a shot. maybe spray a little soapy water around first to see if you still don't get a seal.

 

[theredviper]

Well, connected it to CO2 last night at 10 psi, gave it a bit of a purge and then reconnected by spunding valve, which then showed about 8 psi and holding, so I left it.

Woke up this morning and checked and was up to ~25psi. I set my PRV to around 20 and we'll see how it goes.

Thanks for the tip on adding pressure to seal the keg, that seemed to be it. I had read previously that 20 psi was a good level to set for ferment and carbonating. Does this pressure speed up or slow down fermentation?

 

[odie]

I don't think it will affect the speed...it only suppreses "esters" and such...

I think main benefits are to ferment lagers at higher temps without negative yeast "expression" side effects.

On my Hefe it was a disaster. bland. repitched the same yeast without pressure and got a nice Hefe.

I will not pressure ferment an Ale again until after a few days into the fermentation. Ale need that yeast "expression"

Lagers I will set pressure at the beginning...but I think you really only need a few psi to keep the esters and phenols down.

If you are fermenting at normal temps for the yeast, I really don't think you need to pressurize the keg at all. Just use a blow off tube until it's done or almost done. Then carb it up.

 

[theredviper]

If you are fermenting at normal temps for the yeast, I really don't think you need to pressurize the keg at all. Just use a blow off tube until it's done or almost done. Then carb it up.

Fair enough, I'll see how this one goes and experiment from there.

After ferment, do you cold crash and serve, or wait some time?

 

[odie]

After fermentation is complete I carb it to close to desired CO2 volumes and the keg goes into cold storage until a tap opens up. It's basically crashing until it's served.

 

[Basspaleale]

If you're fermenting under pressure, you are carbonating your beer at the same time. However, I've learned that cold crashing will reduce the pressure in my keg, therefore I set my pressures, for lagers, at 30 psi from start to finish. This will leave my beer at around 12 psi after crashing, ready to serve.

 

[theredviper]

Good tip, I upped the PRV to about 30 psi, we'll see how that goes.

 

[rootAndBoom]

If you're fermenting under pressure, you are carbonating your beer at the same time. However, I've learned that cold crashing will reduce the pressure in my keg, therefore I set my pressures, for lagers, at 30 psi from start to finish. This will leave my beer at around 12 psi after crashing, ready to serve.

Slightly different technique for me: I start off with a lower pressure (maybe 7-10) for the first few days, then raise it to hit volumes when I know the yeast is almost done. My idea is that if the yeast don't like the pressure, at least they've already done most of their job.

 

[micraftbeer]

Couple thoughts here. First of all, yes, fermenting under pressure slows fermentation rate. Typically, you compensate by raising the fermentation temperature (which speeds fermentation rate up). Since the pressure helps suppress esters, you can get away with the fermentation at higher temperature without unwanted flavors.

Remember to consult the carbonation chart to cross-reference your spunding pressure setting at the temperature you are fermenting. Pick your target vols of CO2, look up the temperature you are fermenting at, and that will tell you what to set your spunding valve pressure to.