Questions on pressure fermenting

[ripetti]

A lot of discussions on pressure fermenting have been ongoing recently. I am also interested in the idea and to see if I could benefit from using the technique even though I bottle my beers. I am mostly brewing NEIPAs so any less oxygen involved in the process would be great even though I have been able to brew great beers also with the current setup.

My current idea would be to get a Fermzilla all-rounder and a beer gun for bottling. I am planning to use Sodastream co2 bottle that I already have and I have understood I would need to get a regulator for that and also a spunding valve for the Fermzilla in order to ferment uder pressure and to be able to naturally carbonate the beer.

According to my understanding, with the above mentioned equipment the process could be the following. I have included some questions concerning issues I have not yet been able to find answers to. I would be very happy if someone more familiar with the process could answer some of the questions.

1. After pitching the yeast I would pressurize the fermenter using the co2 and then setup the spunding valve (what determines the suitable pressure at this stage? I have also read that for ales no pressure at this stage would be needed. I guess it wouldn't hurt the process if I add some pressure.)

2. For dry hopping I would need to remove the pressure and repeat what was done in step 1.

3. Fermenting would build up co2 and the beer would carbonate naturally as I have the spunding valve on and correctly adjusted (I assume I would check from a table what pressure is needed given my room temperature. When should I adjust spunding valve to this pressure?)

4. After the fermentation is complete I would transfer the fermenter to fridge. For how long? I assume the beer should be naturally carbonated at this stage? Do I need to adjust the spunding valve before I cold crash or do I need to add more co2 to carbonate the beer properly after the cold crash?

5. After the beer is cold and carbonated I would attach the co2 bottle to both the beer gun and the fermenter. And of course beer line from fermenter to beer gun. Should I use the same pressure for both of these or do I need a regulator for the co2 bottle that can adjust different pressures at the same time for fermenter and beer gun?

I guess everything from here onwards would be according to my regular bottling process.

Many thanks in advance for any help on the issue!

 

[Docod44]

As a side note, I would not recommend immediately pressurizing the fermenter for ales. Doing so is advantageous for a very clean lager-like profile but in ales you typically want some ester production, and pressure fermentation from the get-go can create a bland beer. I've only fermented a lager under pressure so I don't know when you would add pressure to a fermenting ale, but I have read some homebrewers wait until the first dry-hop charge is added 48-72 hours after fermentation has started and then they crank up the spunding valve to 20psi or so and leave it until cold crash.

 

[Jim R]

I don't pressurize my Fermzilla All rounder after pitching the yeast. I have my Spundit 2.0 spunding valve set at approximately my desired fermentation pressure and just let the fermenter gradually build up pressure on it own (which doesn't take very long). Then I fine tune the pressure with the spunding valve as needed to get my desired pressure. I try to dry hop before the end of active fermentation so I can open the fermenter quickly, dump in the hops and then let the fermenter build up pressure again quickly. I could repressurize with CO2 but it wouldn't make much difference. I then eventually do a pressure transfer to my keg and cold crash. I adjust my keg pressure with CO2 to get my desired carbonation level. I don't use the spunding valve in the refrigerator. I usually let the beer age in the refrigerator at 12psi or so for a week because I am not usually in any hurry.

I would consider kegging if you are going to mess around with pressure fermentation. That is the biggest advantage for me. I can easily purge my kegs with fermentation CO2 (free CO2) and then easily do a pressure transfer to virtually eliminate any risk of oxidation. The only other advantage would be to more quickly ferment lagers but I don't do lagers very often. I wouldn't have spent the money on the pressure fermentation equipment (good spunding valve, Fermzilla pressure kit, etc.) just to bottle ales.

 

[stealthfixr]

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 beer is desired (i.e. Cream Ale, lagers, IPLs, some IPAs, etc). I just did an Omega Lutra Kveik batch at 10psi & 72F, and the resulting beer is remarkably clean.--very little to no off flavors or perceived yeast contributions. And, the longer it cold conditions, the more lager-like it is getting. The West Coast IPA before it had superb hop signatures, and very little hop contribution drop-off over time. I think this was largely due (I think) to an oxygen free, unitank process to include O2 free dry hopping (which is fantastic).

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. 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. Pressure transfers 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.

 

[Gnomebrewer]

I would consider kegging if you are going to mess around with pressure fermentation.

^^This

There's no point pressure fermenting and going to extreme levels keeping O2 out of the fermenter, then bottling with a beer gun which will let some oxygen in. At least with normal bottling/bottle conditioning you have active yeast going in that can consume some O2. Alternatively, drink up straight out of the fermzilla without transferring the beer! There are dry hops and yeast in there, so you'd need to finish it off fairly quickly.

 

[ripetti]

Thank you all very much for all the replies so far. The kegging is unfortunately not an option for me. I have the possibility to transfer the fermenter to fridge 100 meters from my house if needed but I would not be able to keep a keg in cold in my home.

My initial motivation for pressure fermentation was mostly the possibility to ferment and bottle with less oxygen exposure, possibly be able to ferment better during hot summer months when it is difficult to keep temperature in control and also to carbonate easily without the need to keep bottled NEIPAs in room temperature for a week or so.

 

[Gnomebrewer]

How about half kegs (2.5 gallon)?

 

[DrStrange]

I tried to pressure ferment with my SSB Unitank but missed the window of opportunity (but first time I tried so a rookie mistake I guess). My issue was the pressure transfer - was a disaster. Couldn't get anything but foam to flow so gave up and did things the old fashioned gravity way and tried to purge the keg of O2 after the fact.

 

[Jim R]

My issue was the pressure transfer - was a disaster. Couldn't get anything but foam to flow so gave up and did things the old fashioned gravity way and tried to purge the keg of O2 after the fact.

They key to a pressure transfer without foaming is to have minimal pressure difference between the fermenter and the keg (like 1-2 psi difference at most). If the fermenter is pressurized to 12 psi, I then pressurize my purged keg to 12 psi. Then with a spunding valve on the keg I connect my hose from the fermenter to the keg and very slowly start releasing pressure in the keg to start and maintain the transfer. Once it looks like it is transferring fine without foam, I can increase the flow a little faster by opening up the spunding valve on the keg a little more. If there is minimal pressure difference between the two vessels, you can actually transfer pretty fast without foaming.

 

[Malty Matt]

They key to a pressure transfer without foaming is to have minimal pressure difference between the fermenter and the keg (like 1-2 psi difference at most). If the fermenter is pressurized to 12 psi, I then pressurize my purged keg to 12 psi. Then with a spunding valve on the keg I connect my hose from the fermenter to the keg and very slowly start releasing pressure in the keg to start and maintain the transfer. Once it looks like it is transferring fine without foam, I can increase the flow a little faster by opening up the spunding valve on the keg a little more. If there is minimal pressure difference between the two vessels, you can actually transfer pretty fast without foaming.

This is exactly what I do and it works well.

I came here to see everyone's experience with pressure fermenting ales. There is some debate whether it does suppress those esters you want. Based on a post above, it does suppress them. I may try what @Docod44 mentioned and start the first 3 days without pressure, let it build up to 10psi, and let it finish at 20-22psi (or whatever the carb calculator suggests) before crashing. Comments?