Question regarding pressure fermenters.

[Ragman]

Hello. One of my friends is considering purchasing a Spike CF10 Conical Fermenter for fermenting under pressure. I didnt really know much about pressure fermenting but he explained to me that it can speed up fermentation, can all but eliminate the chance of oxidation, Eliminate blowoffs, and carbonate the beer before it goes into the keg. Sounds good to me.

Anyway the issue is that we brew in my garage which, in Upstate NY, gets very cold in the winters so leaving the CF10 in my garage during fermentation is not an option. We would either have to leave the CF10 in my basement or at his house and transfer the finished wort to it via buckets or something as we do 10 gallon batches regularly. Transporting either a full CF10 or full boil kettle would not be an option either.

Question is, have any of you done this? Im thinking the risk of contamination along with the hassle of transferring the wort twice may not be worth the advantages of using the CF10.

What do you think?

 

[VikeMan]

I didnt really know much about pressure fermenting but he explained to me that it can speed up fermentation,

Fermenting under pressure doesn't speed up fermentation. It slows it down.

can all but eliminate the chance of oxidation,

The way to avoid oxidation is to avoid oxygen. You can do that with a spunding valve without fermenting at high pressures. A couple PSI (not a lot higher than when fermenting with an airlock) will do.

Eliminate blowoffs,

Eh, maybe. But IMO, the best way to eliminate blowoffs is with an appropriately sized heasdspace.

and carbonate the beer before it goes into the keg.

Yes, you can certainly raise the pressure toward the end of fermentation to carbonate, but for practical reasons, it's better to do that in a keg, IMO. Transferring fully carbonated beer can be tricky. Also, conical fermenters vary in their pressure ratings. At room temp (68F), to reach 2.5 volumes of CO2, the pressure is going to reach almost 28 PSI. The fermenter you mentioned is rated for 15 psi, IIRC.

 

[Vale71]

... he explained to me that it can speed up fermentation ...

He's wrong, actually. Pressure slows down fermentation and it also heavily affects the charachter of the beer. Pressure fermentation is a modern commercial practice used to brew lager beers at much higher temperature (up to 20°C) while retaining the lager character. In that case fermentation is indeed faster but only compared to a traditional low temperature fermentation and the speeding up occurs because of the higher temperature, with the pressure actually making it run slower that it would have run given the same fermentation temperature.
Ales fermented under pressure at the usual temperature will take longer and will generally turn out a disappointment. As a matter of fact pressure fermenting an ale makes no sense at all.

 

[Knightshade]

In keeping with Spike product...maybe a fermentation chamber where you can control temp a little more effectively, with a (or 2) Spike Flex+ might work?

 

[stealthfixr]

Question is, have any of you done this? Im thinking the risk of contamination along with the hassle of transferring the wort twice may not be worth the advantages of using the CF10. What do you think?

Yes, I've got a Spike CF-5 and have tested pressure fermentations with about a dozen batches after decades of non-pressurized brewing. For making a clean, non-oxidized IPA, I have found pressurization to be fantastic, or any style where being 'clean' tasting is desired (i.e. Cream Ale, lagers, IPLs, some IPAs, etc). It's also really nice to go straight into a keg already carbonated and at temperature (via glycol chiller). I am doing an Omega Lutra Kveik batch right now at 10psi & 72F, and samples are coming out remarkably clean.--very little to no off flavors or perceived yeast contributions. It's not done, but I would call it lager-like so far.

I have also found, as soon mentioned above, that pressurized fermentations are *not* for every beer style or yeast. For example, I did a Saison recently and kept only about 1-2 psi during the primary fermentation, with the intent being to keep the conical 'free' of any potential contaminants. It's nice to not need a blow-off hose & bucket. The resulting Saison noticeably lacks that unique yeast contribution character that I've gotten from non-pressurized fermentations. OTOH, I did a Porter recently with 1098, and just installed the blow-off hose adapter than came with the CF-5, and viola, the right yeast signature is there.

That said, after that Porter finished fermentation, I pressurized to 10psi and cold crashed it to 37F for couple weeks. Sampling before and after showed that post-fermentation pressurization did not have any negative effects, but cold conditioning did have positive ones. Transfers under pressure to a keg are also so darned easy--like a 15 minute task.

I am getting rid of every non-pressurizable fermenter, if for nothing else than the easy transfers to a keg. In fact, I may buy another CF-5/10. My CF-5 holds pressure like a champ and has never leaked. SS makes clean-up easy--love my CF-5.

 

[VikeMan]

It's also really nice to go straight into a keg already carbonated and at temperature (via glycol chiller). I am doing an Omega Lutra Kveik batch right now at 10psi & 72F, and samples are coming out remarkably clean.--very little to no off flavors or perceived yeast contributions. It's not done, but I would call it lager-like so far.

I'm not sure I'm following what you're doing, but 10 PSI at 72F will settle at less than 1.3 volumes of CO2. I wouldn't consider that to be "already carbonated."

 

[Panderson1]

Funny how i took a 3 year break from this hobby and now in 2021 all i hear about is pressurized fermentation. Only used to hear about that with really expensive gear and at pro breweries. Good stuff.

 

[ChiknNutz]

I use a Kegmenter which is rated to 50psi, though the relief valve is set at 35psi...more than adequate for what I've used it for thus far. The way I use it is with a corny keg and a spunding valve. During fermentation I set the spunding valve (which is attached to the keg) to a low pressure, generally less than 5 psi. If I want to naturally carbonate, I transfer to the keg at the tail end of fermentation so you can still capitalize on the CO2 production. For this to work, you have to time it right (like 3 days into fermentation or so, not much longer I've found). The last couple of times I've waited too long and missed my window to naturally carbonate. After transfer (via pressure of course), I then set the spunding valve to my desired pressure, upwards of 30 psi in order to fully carbonate at room temperature.

EDIT: I forgot to mention that the other advantage of this method is the fact that the destination keg is CO2 purged in the process, so an oxygen-free transfer can easily be accomplished.

One point to note on the pressure transfer from fermenter to keg. While you can start the transfer using the pressure produced during fermentation, it is not sufficient volume to fully transfer, so you do need an alternate source of CO2 to complete the transfer.

I've not really used it for "pressure fermentation" as it seems most suggest it tends to produce some off flavors, or at least a muted flavor profile. YMMV.

Here are a few pix.

 

[stealthfixr]

I'm not sure I'm following what you're doing, but 10 PSI at 72F will settle at less than 1.3 volumes of CO2. I wouldn't consider that to be "already carbonated."

It's still in primary--not carbonated yet. When fermentation & diacetyl rest are done, I'll pump it up to 10 psi and cold crash--then it will carb. My point above is that it nice to have the option with the CF-5 to carbonate before going into the keg. I transfer to the keg, which goes right into the kegerator, and can be poured right away.

 

[McKnuckle]

When fermentation is done, you will have a hard time cranking up the pressure to anything. You'll only achieve or increase pressure when fermentation is actively producing CO2. That's the trick to spunding - containing the CO2 while its still being produced, but not too early or too late.

 

[VikeMan]

When fermentation & diacetyl rest are done, I'll pump it up to 10 psi and cold crash--then it will carb.

Where will the CO2 come from?

 

[stealthfixr]

Where will the CO2 come from?

From a CO2 bottle connected to the CF-5 pressure manifold.

 

[Ragman]

Pretty interesting views on this. I think my friend was referring to lager fermentaion when he mentioned it being quicker - and also the carbing as well.

Im mostly concerned about the fact that I have to dump the wort into buckets, drive the buckets to my friends house, then pour them into the CF10.

 

[stealthfixr]

When fermentation is done, you will have a hard time cranking up the pressure to anything. You'll only achieve or increase pressure when fermentation is actively producing CO2. That's the trick to spunding - containing the CO2 while its still being produced, but not too early or too late.

Good thing I use a spunding valve with an adjustable PSI limit. Anyway, I find that if I have 10 psi at ale temps post-fermentation and then cold crash, I have about 5 psi at 38F or so. Then, using the Spike Carbonation Stone to the CF-5 racking valve makes carbonation up to 15 PSI easy.

 

[VikeMan]

From a CO2 bottle connected to the CF-5 pressure manifold.

Anyway, I find that if I have 10 psi at ale temps post-fermentation and then cold crash, I have about 5 psi at 38F or so. Then, using the Spike Carbonation Stone to the CF-5 racking valve makes carbonation up to 15 PSI easy.

I'm confused. Which is it?

 

[stealthfixr]

The pressure manifold on the lid can be used for adding pressure via a CO2 bottle, like for transfer to a keg or adding PSI before a cold crash to ensure positive pressure. It's also where the spunding valve goes to control pressurization during fermentation, which I built from a homebrewfinds.com article and common parts on Amazon. The carb stone connects to the racking valve down on the body of the CF-5 and has it's own ball lock gas port at the end, and this is how it's carbonated, via the same CO2 bottle. One can add pressure to the CF-5 either way, for different reasons. Nothing mysterious here.

There's lots of videos on the Spike website that describe all of this very clearly--I did not invent any of these practices. The only thing I do that wasn't in a Spike video is using the lid with a butterfly valve to dry hop without any O2 exposure (this is very cool)--copied from other Spike users here.

 

[BierHobo]

So, regarding the comments about fermentation speed.....I'm pressure fermenting a lager for the first time and my temp is at 64°. What should I expect for complete fermentation time?

 

[crazyjake19]

So, regarding the comments about fermentation speed.....I'm pressure fermenting a lager for the first time and my temp is at 64°. What should I expect for complete fermentation time?

Mine regularly hit final gravity in 6-7 days at 62-65F for a 4.25 gallon batch. Just my experience, your results may vary.

 

[BierHobo]

Here's another question for ye experienced in the ways: Do you oxygenate before fermenting?

 

[stealthfixr]

I do, 1 minute every time for Sachs yeast. Stone connected to an O2 tank (red) from Lowe's.

 

[Gusso]

Yup. But I just hit it hard for 30 seconds. I just did my first pressurized lager 6 days ago. Fermentation is now complete with one pack of 34/70.