Value of degassing vs lost flavors / aroma

[rfelsch]

Hi all,
New to meadmaking this year. I definitely have caught the affliction. Up to 70 gallons so far. have enough honey to do 100 gallons total. I am looking to create a storehouse of mead that is long term aged with 2015 vintage honey (so the vintage matches this first year of owning our farm). So far I have been reading everything I can get my hands on. This forum has been a wealth of information for me. Thank you. My first two 10 gal. batches followed Ken Schramms instructions from "The Compleat Meadmaker". They were fermented between 62-68 degrees using D47. The first batches OG were 1.128 and 1.120 finished at 1.027 and 1.019. 13.62% and 13.53%. My next batch was a little bigger... 1.136 OG still fermenting slowly at 1.015 and 15.27%. This batch used SNA and regular degassing even beyond the first several days. I figured the demijohn & airlock eliminates the exposure to oxygen with the later degassing.
Now the question.
It seems pasturizing the must, even at a low temperature is frowned upon due to loss of delicate flavors and aroma's. At the same time, it seems that degassing several times a day gets a big thumbs up with no mention of lost flavors and aroma's. I seem to be overshooting my target ABV with the SNA and degassing. Should I skip the degassing as unnecessary to protect the delicate flavors and aroma's. Does the degassing cause a loss of good stuff, or is that different than heating. Does the degassing help enough to offset the loss? I understand degassing helps to make the product drinkable sooner, but does it help overall if I am planning on long term aging anyways? Thanks for all the help I have already gotten by reading your forum!

 

[TandemTails]

70 gallons is impressive! I thought my ~25 gallons in the last 8 months was a lot, haha.

Like you, I've been reading a lot about proper fermentation for mead and it seems like there is a lot to take in. This is an interesting question and something I'm not too sure about. I know people have opinions about this subject in regards to adding fruit/spices in primary vs secondary but i'm not sure about traditional meads.

My only real guess would be that aerating/degassing isn't really doing anything the process wouldn't do if left on its own. If the aromatics are going to be lost, they'll either happen when fermentation is left alone and active or they'll be lost when you're aerating/degassing. At least with aerating/degassing you're keeping your yeast healthy and active so there will be less of a chance of other off flavors or aromas present in the final result.

 

[rfelsch]

Makes sense but it sure seems like the total amount lost is greater when the airlock is belching those aromas so forcefully. Purchasing a 30 gal kettle setup for all grain brewing and 1/2 dozen 14 gallon demijohns has helped increase the volume of each batch. The fever is strong.

 

[rfelsch]

Is it wrong to continue degassing late in the fermentation if I am doing primary in a carboy with an airlock?

 

[rfelsch]

BTW I am not opening the airlock and letting oxygen in when i degass. I am simply swirling the carboy until the airlock calms down. I am aerating daily for the first couple days using oxygen and a .5 micron wand. After that I do not open the airlock except to draw a quick sample for testing.

 

[loveofrose]

Esters (aromatic compounds in honey and produced by yeast) are not that volatile (meaning evaporate into the air). When folks say a flavor is "blowing through the airlock", this is only a perception. The fact is that some yeast produce esters ( Ex: KIV1116) and others are neutral (Ex: EC1118). Yeast choice matters!

Boiling is a whole different matter. Boiling at high temp drives off esters that a room temp ferment could never hope to drive away; hence the bad rap.

Degassing is about yeast health. It removes CO2 from the must which lowers pH and is a waste product the yeast would prefer to not be around; it stirs yeast into the must thus making them efficient in producing ethanol; and it prevents compacting yeast on the the bottom of the carboy from autolysis (yielding off flavors).

For more reading material that is current, see the articles section of my site:
www.denardbrewing.com

 

[rfelsch]

I appreciate the explanation. My yeast seem to be pretty happy with the degassing efforts. All things being the same, it seems like degassing is going to push the D47 alcohol tolerance more than 2.5% higher than the similar batches that were not degassed. Even though I was shooting for 14% alcohol, I would think that the high gravity + 16% alcohol should help preserve the mead for long term aging.

 

[rfelsch]

Any input on degassing throughout late stage primary when the oxygen exposure is limited by the carboy / airlock combination?

 

[Yooper]

Any input on degassing throughout late stage primary when the oxygen exposure is limited by the carboy / airlock combination?

Since the only reason to degas is to stir the yeast in suspension and to rid the mead of excess c02, it's time to stop doing that when the SG falls and fermentation slows.

mead is not as susceptible to oxidation as wine is, but it still is not immune.

If you don't have a reason to degas, then why do it? I don't understand that. If you have a reason (for the yeast health), then it should be done. Once fermentation slows and ends, I allow the lees to fall and then rack off of the lees into a new vessel and top up.

 

[rfelsch]

Thanks for the response Yooper. The reason I am still degassing late stage is to knock the foam down on one of my batches. I started it 2/24 with OG of 1.136 is now at 1.024, 15.2% abv, still fermenting and producing large bubble foam that is bubbling into the airlock overnight. The Other batch I am still degassing is one that I added blood orange juice to when primary was nearing completion. The pulp floats to the top and I was under the impression that the pulp should be mixed twice daily to reduce the likelihood of mold formation. The blood orange batch (16 gals. 53lbs honey)started on 2/24 OG 1.124 fermented down to 1.022, 13.7% abv when fermentation slowed on 3/6 I added 2.5 gals blood orange juice + 25.8lbs honey & 2 Tbl pectic enzyme. this brought the gravity back up to 1.075 sg & 9.34% abv. I calculated that the new starting gravity would be 1.144. Today, (3/11), gravity is now at 1.056, 12%ABV.
Summarize, I am degassing to knock down foam on a foamy batch & stirring in pulp on juice added close to end of primary.