Couple of questions - for ciders, pressure fermenting? Air exclusion?

[Cider Wraith]

A guess would be most ciders are carboy fermented and open-air syphon transferred - my best successes were with those methods and brings up the reason for this post. Kegging is convenient. Since rekindling this recreation have moved into keg fermenting with C02 exhaust lines running through "servers" and following fermentation making closed-system "O2 excluding" transfers. Also purchased a couple of pressure fermenting valves to experiment with natural carbonation. All of those methods work technically very well, but bring up questions.

Is anyone aware of a flavor reduction from pressure fermenting ciders? Pressure fermentation is desirable with many beers (not all?) but can't seem to find anything addressing the question with ciders. And incidentally, isn't bottle carbonating simply micro-scale pressure fermenting? Is anyone aware if pressure fermenting ciders might result in reducing fruity flavors and complexity?

Is anyone aware of there being an advantage to admitting air to the cider making process? For open-air carboy transfers the cider is being washed in air, and can result in great outcomes, but for "O2 excluding" transfers air is obviously eliminated. Yet is anyone aware of air exposure for ciders being advantageous during the fermentation cycle and being a flavor enhancer? Seems counterintuitive, but could it be possible?

Thanks for any feedback, personal experiences, and happy to hear any wild guesses -

 

[Maylar]

Is anyone aware of there being an advantage to admitting air to the cider making process?

No. Other than O2 being required for the aerobic phase of fermentation (first couple of days).

Sorry about the rest, but I have no idea what pressure fermentation is.

 

[Cider Wraith]

thanks for the reply -

 

[Cider Wraith]

Wanted to give this thread a final friendly bump ... ignoring the pressure fermenting issue would still appreciate any additional feedback on exposure to air at any point during cider-making being desirable - trying to gain insights on this apparent mystery. Wild guesses and input appreciated.

 

[JulianDave]

Pressure fermentation is done a lot in beer brewing, so a thought would be to ask over there what it does exactly and figure out if it's relevant to cider. Or do the exact same batch with pressure fermentation as the only difference to see what you think.

As far as O2, what Cider Wraith said. It's needed to build a healthy colony of yeast, but then you don't generally want it as alcohol fermentation is anaerobic. I did read that racking red wine with O2 is a thing and can be helpful, but it didn't mention doing this with white wine at all, so seems likely cider wouldn't be helped either, at least in the way red wine is. Again, doing an exact batch and treating them with this variable different would be interesting.

 

[Cider Wraith]

Thanks for the replies @JulianDave and @Maylar

Seems intuitive that oxygen exposure could only detract from ciders, right? - only natural ... but maybe there's more to the story?

Rekindled my interest in this recreation several months ago and was getting such successes with carboy fermenting and open-air transfers was motivated to purchase more equipment and move to keg fermenting. Keg fermenting makes for easy closed-system fermentations and transfers keeping the whole process "02 free".

Staying focused on "oxygen exclusion", but also making other changes, flavors declined. Blindly turning out the best carboy successes it wouldn't be uncommon to find an air lock stuck open and of course transfers were conventionally open-air with lots of air mixing - but upon trying them, outstanding.

Appreciate it sounds highly unconventional but trying to work out if admission of 02, at right times during or after primary fermentation, could be beneficial specifically in cider making; seems to be next to nothing on this but there do seem to be a couple of university papers that address the question. Thinking back, there were a few keg batches that for whatever reason the lid was opened during / after fermentation and they came out particularly well. How could it be?

Yes, am doing some testing as suggested. Additional chit-chat and as always wild speculation appreciated -