would pressurizing a cider help to retain apple aroma

[fluketamer]

when i ferment motts apple juice it usually gives sulfur about day ten for 1-2 weeks. however after the sulfur burns off it off-gasses the most delicious apple aroma for several days at least. my ferm chamber smells like an apple orchard on a crisp fall day. i would love to retain more of that in the cider. would maybe capping the fermenter and adding a little co2 to finish it under pressure retain some of that aroma. has anyone tried this with success . Is it worth a try?

 

[Chalkyt]

Everything is worth a try, after all I am told that ladies have to kiss a lot of frogs to find a prince! We have all tried a few things that didn't work but at least you find out what doesn't work.

Guessing what is going on... two weeks fermentation sounds like the SG is getting fairly low, say 1.005. I read somewhere that "flavour and aroma tends to blow off in the last 5 or so gravity points. I wonder if that is happening with your cider. If that is the case, sealing it up for the last 5 gravity points will only generate 2-3 volumes of CO2 (i.e around 30psi at typical 15C fermenting temperature), so nothing should "blow up". And you never know, it might work.

 

[Bobby_M]

Most likely it will retain way too much sulfur. Apple aroma is typically enhanced by acid, which drinking apple juice is lacking. Try adding some malic acid or citric, lemon juice, whichever.

 

[fluketamer]

Most likely it will retain way too much sulfur. Apple aroma is typically enhanced by acid, which drinking apple juice is lacking. Try adding some malic acid or citric, lemon juice, whichever.

thanks bobby i got the flavor. i add lime juice it works great and back sweeten with apple which makes it very well balanced. its basically grahams cider recipe. which is execellent supermarket juice cider. it includes tea tannins and lime juice to add back what the juice is lacking.
its that aroma that is leaving that i thought i might be able to keep. i want to try it after the sulfur blows off which is pretty evident around day 25-30.

this one i backsweetened with cherry and apple juice

i will prolly try this in a small keg and spund it until a few point like chalky said - kissing the frog so to speak.

 

[Raptor99]

I'm not sure what type of fermenter you are using, but I've found that a carboy with an airlock retains most of the flavor. If it is fermenting very slowly, then not much gas will be coming out of the airlock. With an open bucket, on the other hand, you lose a lot more flavor.

With adequate nutrients, my grocery store hard cider is usually mostly done fermenting within about 5-6 days. At that point I rack it from the bucket into a carboy. If there are not enough nutrients, the yeast will produce sulfur odors.

I am interested to hear what happens if you seal it up and let the pressure build for the last part of the ferment. As @Chalkyt said, if you know the SG, you can calculate the volumes of CO2 that will be produced and end up with properly carbonated cider.

 

[Chalkyt]

Yep, my take on it (which might be completely wrong) is that if the fermenting cider is sealed for the last 5 gravity points or so, you end up with about 2.5 volumes of CO2 which is taken up by the cider because it can't go anywhere else. (SG1.005 = 9g/L sugar x 47% = 4.2g CO2/1.87g/L i.e. the density of CO2 at 15C = 2.3 volumes of CO2 and any other gaseous compound being kept in the cider).

I guess the question is, do the aroma compounds otherwise "blown off" also get absorbed back into the cider then released with the CO2 when it is opened. I am certainly not a biochemist but maybe someone out there might be able to comment.

 

[Raptor99]

My experience with country wine as well as cider is that a fast, vigorous fermentation blows off more flavor. Fermenting more slowly at a cooler temp generally helps to preserve flavor.

From this post https://www.homebrewtalk.com/threads/fermentation-temps-for-hard-cider.575512/post-7467877:

From what I've read in Claude Jolicoeur's book, he recommends using a champagne yeast at 50°F.

Claude Jolicoeur is an internationally recognized cider expert and the author of The New Cider Maker's Handbook.

Here is a research paper on this topic: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7919833/
They compared fermentation of white wine at 20 degrees C (68 degrees F) vs. 12 degrees C (53.6 degrees F). Their conclusion:

The largest amounts of esters were produced by S. cerevisiae yeast at 12 °C. Other amounts of volatiles were also higher at lower temperatures. These results suggest that temperature is not as significant as the yeast strain used for wine production but that lower-temperature processes lead to better sensory profiles than those conducted at higher temperatures.

Volatile esters are a key part of the aroma and flavor of wine and cider. The yeast strain will influence which esters are produced during fermentation, but temperature will affect both the amount of esters produced by the yeast as well as how well the esters in the fruit are preserved.

My wine room is at 65 degrees F, so that is my fermentation temperature right now. But I am thinking about how I could ferment my cider at closer to 55 degrees F. Some cider yeasts and ale yeasts will work well at those temperatures.

I guess the question is, do the aroma compounds otherwise "blown off" also get absorbed back into the cider then released with the CO2 when it is opened.

I am not sure about this either. But even if they are not re-absorbed, the aroma compounds will remain in a sealed vessel until it is opened. When you serve out the cider from the keg, they will be released to contribute to the flavor and aroma of the cider. That assumes that the final part of fermentation is done in a keg, and that you don't open the keg again before serving.