How important is degassing during mead fermentation?

[NeverDie]

I was surprised to see a recommendation for degassing mead on days 1, 3 5, 7, and 8: https://www.homebrewersassociation.org/how-to-brew/improve-mead-staggered-nutrient-additions/

Elsewhere, I've seen some people recommend degassing every day. Others even recommend doing it every 12 hours.

Does it really matter? I mean, won't the mead must pretty quickly become re-carbonated anyway?

Assuming the answer is that it is important, how strong of a vacuum should one apply? This vacuum pump looks like it would do the business pretty well:

https://www.amazon.com/dp/B01N0SYCL4/?tag=skimlinks_replacement-20

But how much vacuum is too much?

 

[GnenieGone]

I was surprised to see a recommendation for degassing mead on days 1, 3 5, 7, and 8: https://www.homebrewersassociation.org/how-to-brew/improve-mead-staggered-nutrient-additions/

Elsewhere, I've seen some people recommend degassing every day.

Does it really matter? I mean, won't the mead must pretty quickly become re-carbonated anyway?

Assuming the answer is that it is important, how strong of a vacuum should one apply? This vacuum pump looks like it would do the business pretty well:

https://www.amazon.com/dp/B01N0SYCL4/?tag=skimlinks_replacement-20

But how much is too much?

If I may be so bold there are 2 things that occur when degassing. 1st the diffused CO2 is liberated from the mead. Yeast dosen't want to be around CO2. I just take a sanitized stiring wand and dive in. 2nd with opening of the fermenter, there will be some reoxygenation to help continue the fermentation process.

Same thing with high gravity beers. The need to reoxygenate at 12hrs is a must.

 

[SanPancho]

Doesn’t take much. A few psi. When the bubbles stop you’re done. Id be a bit averse to a pump and just use a plunger type tool you could seal over carboy neck. But folks have definitely used vacuum pumps before. There are probably videos here if you search specifically in the subforum.

 

[NeverDie]

I see that loveofrose has a different perspective on it: https://www.homebrewtalk.com/forum/threads/aerating-vs-degassing.643984/

On the other hand, here: https://www.homebrewtalk.com/forum/threads/completely-mental-cyser-bomm.576526/#post-7494165
loveofrose advocates degassing every day until the last nutrient addition.

 

[CKuhns]

I release CO2 with a wand 2xs a day until 1/3 sugar break. Up to that point your yeast are mostly in their aerobic state and need a little O2. After 1/3 break then they go anaerobic and I personnaly don't think CO2 really matters. After 1/3 sugar break you really do not want to introduce air as that causes off flavors due to oxidation. As mentioned yeast get stressed with too much CO2. It sure seems to help my preferred yeast. Some type of CO2 release appears to be what most folks prefer. But of course not all.[emoji6]

When I think of degassing with a vacuum pump it typically is done just before bottling. It drives out the last bit of CO2 and some folks say it makes for a better aging process in the bottle. I have never tried it so have no first hand knowledge.

 

[DevilDogmeadguy]

I release CO2 with a wand 2xs a day until 1/3 sugar break. Up to that point your yeast are mostly in their aerobic state and need a little O2. After 1/3 break then they go anaerobic and I personnaly don't think CO2 really matters. After 1/3 sugar break you really do not want to introduce air as that causes off flavors due to oxidation. As mentioned yeast get stressed with too much CO2. It sure seems to help my preferred yeast. Some type of CO2 release appears to be what most folks prefer. But of course not all.[emoji6]

When I think of degassing with a vacuum pump it typically is done just before bottling. It drives out the last bit of CO2 and some folks say it makes for a better aging process in the bottle. I have never tried it so have no first hand knowledge.

So, I have a follow up question, I'm having an issue with a Mead I'm almost ready to finish. I've been stuck at 1.05 gravity for two days now and it seems like the yeast is slowing down quite a bit. I have already racked it once, so a bit of a slowdown in fermentation is to be expected but it's almost stagnant. A good amount of bubbles still coming up, I'm trying to finish with a gravity at OR below 1.01 so I have a bit to go yet. I'm using Lalvin EC-1118 so the yeast is a hearty yeast, I've never had this issue before but I'm afraid to stop it up too much because I don't want it to oxidize. Any thoughts?

 

[Miraculix]

I would really like to see some studies about the positive effect of degassing. From my experience, the liquid gets rather quickly completely saturated with Co2 again, so the degassing has maybe a co2 reductive effect for 30 minutes and afterwards the level is up again. Even when done twice a day, this doesn't really look like a significant thing to me under the described conditions. Unless we are at the end of fermentation when co2 production slowed down a lot, but then, degassing is not practiced anymore. So maybe it is actually more about the introduction of additional oxygen, than degassing.

@loveofrose , do you have some additional knowledge on this topic?

 

[CKuhns]

DevilDog - EC1118 is a pretty strong yeast and typically will drive to <1.000. In this case it might take a little more time. (Could be any number of things causing the slow down) If you have an airlock on it, then I would just let it go for another couple weeks.

 

[DevilDogmeadguy]

DevilDog - EC1118 is a pretty strong yeast and typically will drive to <1.000. In this case it might take a little more time. (Could be any number of things causing the slow down) If you have an airlock on it, then I would just let it go for another couple weeks.

OK, yeah it's a 5 gallon batch with airlock. I will just let it keep going lol. Thanks, just never had that issue with 1118 before its usually fire and forget. Thanks for the reassurance!

 

[NeverDie]

This guy uses a high quality vacuum pump to degass his wine. Even with that, guess how long it takes?



He says it takes a half hour to fully de-gass his carboy of wine if using his vacuum pump.

Which leads me to think that degassing by merely giving the carboy a few shakes is only getting a relatively small fraction of it. I'm guessing the same may be true for a degassing whip attached to a power drill, unless you were to whip for something like a half hour also.

 

[CKuhns]

I cant soeak gor wine makers and think they may have different ideas and practices. I think people are using the same term for two things. Releasing CO2 and maybe adding a little air at the beginning of fermrent and degassing mead

 

[Maylar]

The concept behind degassing is that CO2 in suspension creates carbonic acid which lowers the pH of the must and makes the environment more stressful to the yeast. There is a growing faction among wine makers who believe that the difference is so minute that it's not worth the effort. If you have a pH meter, you can find out for yourself - measure before and after - and report back

Stirring the lees however, has another benefit in that it keeps the yeast in suspension which has proven to be beneficial to the ferment.

 

[CKuhns]

Sorry posted from my cell beford finished - lets try this again.

I cant speak for wine makers and think they may have different practices. As stated above, I also think some folks are using the term degassing for two different things.

1. When relessing CO2 and adding a bit of air.
2. Removing entrained CO2 as part of the finishing process after fermentation is complete.

The second would take a longer time.

With that said, a plastic better bottle or glass carboy and that pump certainly could give you trouble. they just are not designed to take a vacuum as low as that will get you.

 

[NeverDie]

I tried using a foodsaver vacuum pump to de-gass, but it's almost a joke. It does de-gass a little bit, but its vacuum is too weak to get the job done effectively.

So....I just now ordered these two things that should absolutely handle any degassing:
A 8.4 gallon stainless steel vacuum chamber: https://www.amazon.com/gp/product/B07CJLVYKY/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

and a serious vacuum pump: https://www.amazon.com/gp/product/B01N6IOBWF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

If I were to put a battery powered stirplate inside, I could probably automate the stirring and degassing entirely. Then I'd only need to get involved to add nutrients at the first and second sugar breaks.

 

[ScottishCelt]

I keep seeing the term "sugar breaks." Please explain this for me.

 

[CKuhns]

This is a pretty old thread and your question is a bit off topic - You may want to start one of your own to get more responses than just mine.

With that said - Sugar breaks are where you do something to the Mead. i.e. at 1/3 sugar break add a given amount of nutrient.

To calculate sugar breaks determine your Specific Gravity prior to yeast pitch with a hydrometer then do the math.

Example 1/3 sugar break
If your SG / OG = 1.090
Then 1.000 is the SG of water and is subtracted leaving you with the sugars in your honey contributing .090.
1/3 of .090 = .030
So 1.090 (Your original SG) - .030 (1/3 drop in sugar) = 1.060 and that is your 1/3 sugar break.
Works for any fraction you want to use.
This only works perfectly if your ferment goes back to 1.000 (All your sugars are consumed in the fermentation process)
However for what we are doing even if your ferment goes a little low or stays a little high is still likely good enough.

 

[Redeemer]

This is subjective to discuss but it is absolutely real. When I first started brewing I exclusively used glass caboys and stuck an airlock on there at day 1. By day 4 or so the nice fruity fermentation smells would be replaced with sulfur and weird bread aromas and stank. When I learned about SNA it helped a little bit but not much. Then I discovered this forum and the BOMM method which led me to research on degassing. Not sure why I had resisted for so long but now I do ALL of my primaries in a plastic bucket, with the lid just placed on top and I degass / aerate with a wire whip 4 to 5 times a day during active fermentation. I believe that:
1. Reducing CO2 and therefore carbonic acid is essential to minimizing yeast stress
2. Oxygenating the must is more beneficial than detrimental as I have never seen a must oxidize during active fermentation and it is (in my opinion) good for the yeast at this stage
3. Keeps the lazy yeast in suspension allowing the overall mix to be more homogeneous, so the temperature, CO2, alcohol, and fermentable sugars are the same throughout the container, facilitating faster and more complete fermentation.

Ever read the book "Who Moved my Cheese"? Yeast hate radical changes in their environment.

I say this is subjective because this is based on many articles and opinions I have read, but I am not a scientist and don't have hard data to back any of this up. But I have experience, and my experience is in an identical recipe, mead in a bucket that is frequently aerated vs mead in a carboy (even if shaken religiously) is simply better. It is ready sooner, and requires far less aging, as requiring me fewer "What did I do wrong this time?" posts on the HBT forums.

My advice is, without knowing if any of what I just posted is scientifically accurate, try a few of those things and see the results for yourself. Smarter folks than I can comment on the specifics.

 

[Maylar]

Yeast need oxygen during the initial growth phase. After that, they don't. Aerate the must well when pitching the yeast and 24 hrs after you see activity. From then on your degassing should be gentle stirring but not aggressive whipping.