Degassing mead - what do we mean?

[Mr. No-Tip]

So I have about 40l of mead going on at the moment in vessels of various sizes. I am a bit over a week into fermentation and degassing every few days.

My understanding is the following:

• Degas relatively frequently during primary, especially before nutrient.
• Degas before racking.
• Degas before bottling.

(let me know if you disagree with those understandings)

But what does degassing mean? I have been doing a few methods this week, in order of effectiveness:

• Ghetto Wine whip (valpar hose in a drill) I've stopped this now as I don't want to introduce more oxygen (I think)
• Shaking.
• Winesaver sucking through an airlock (very slow...for my vessel that is too full)

Do I want to degass until I see no bubbles? Maybe at bottling, but are we just looking to get 'a lot' of C02 out at this stage? Shake until I get less frothing? No frothing?

Mead making. It's like going back to the beginning!

 

[boonchu]

Ok here goes.
Degas every 12 hours for the first 7 days.
Don't bother degasing before racking as the actual racking will bring out the gas and put a layer of co2 in the new fermenters.
Bottling is optional.
The big units use a pump over system others use paint stirers. I use my mash paddle.
You are looking to remove the dissolved co2 and in the first 7 days add o2. At bottling you are doing it to make bottling easier

 

[Airgead]

I have never degassed a mead in 20 years of meadmaking. Why would you? Its an extra step that can go wrong and I can't really see any benefit in doing it.

Cheers
Dave

 

[Yeastfridge]

What's the idea behind degassing? Getting rid of CO2 to get more O2 in during fermentation? Never heard of it is all

 

[MHB]

Likewise a new one to me, been brewing Mead on and off for over 30years and have never heard/read about the idea of degasing.
The only thing that comes to mind is that if you were fermenting in a closed container (i.e. other than having an airlock) it might be a good idea to vent them occasionally as mead ferments can potter along for a long time.

Let us know where you heard about the idea of degasing, always willing to learn something new, especially if it's going to make me mead taste better.
Mark

 

[Mr. No-Tip]

It was a question asked at ANHC and has come up in my reading here and there.

It doesn't come up in "mead basics" type reading but there's plenty of info if you search for it.

My understanding is that early ferment degassing removes "toxic" C02 and adds oxygen for a healthier ferment. It also reduces the chance of a blow over if staggering nutrients and adding them dry.

As Boonchu said last night, degassing not at bottling can avoid foaming.

I had also heard that removing what dissolved gas remains at bottling time can make for a smoother mead as you're not getting a spec of carbonic acid. There must be very little left in an aged mead in any case, though.

 

[GalBrew]

I also thought that you de gassed if you are doing staggered nutrient additions so the mead doesn't explode everywhere when you add these nutrient additions.

 

[Airgead]

OK.. I can kind of get it for staged nutrient additions. Adding a bunch of nucleation sites to a liquid with dissolved gas can lead to much foam. Although you could say that just adding the nutrient is in fact de-gassing the mead...

Staggered nutrient additions is something else I have never seen the point to. But if you do, just dissolve them in some water... problem solved.

I don't buy the de-fas for a healthier ferment. By the time the yeast starts metabolising sugars into c02 to produce any dissolved gas, they are running anaerobic and the last thing you want to do is introduce o2 at that point. The aerobic phase is their growth phase and if I read my literature correctly, you are talking hours or at most a couple of days there not weeks. They do add o2 (by plunging the cap and other things) to red wine production but that's not for fermentation health (as I understand it) its to extract more colouring from the oxidisation of anthrocyanins in the grape skins. Those soak up the o2, turn that lovely red and protect the wine from the effects of 02. Those compounds aren't present in mead so your risk of damaging the mead by introducing oxygen is much higher than in a red fermenting on the skins.

By the time a mead has fermented out, been racked to a secondary then bulk aged for a month or two there is 9/10's of f all dissolved gas left anyway so bottling shouldn't be a problem. I have never had a foamy mead at bottling time.

Cheers
Dave

 

[Mardoo]

De-gassing is used all the time in wine making. By GENTLY agitating the fermenting must you help get CO2 out of the ferment without introducing oxygen. This is said to help keep pH from dropping too low for healthy yeast function. In "The Jamil Show" mead show with Ken Schramm they discuss de-gassing as applied to mead.

http://thebrewingnetwork.com/shows/The-Jamil-Show/Mead-The-Jamil-Show-12-01-08

I have very little experience in this regard, and am mostly communicating what I've read and heard in 12 years in the wine industry. However my mead ferments have not gone to as low a pH when I have de-gassed.

 

[Airgead]

Interesting... I'm assuming the Ph drop is prevented by stopping the formation of carbonic acid through dissolved co2.

Interesting. I use no acid additions in my mead at all. Never check the Ph either. Might measure one of the ones I have going now to see what it is. I suspect though that in a low acid must, a bit of carbonic acid isn't going to drop things below a healthy range for yeast anyway. Maybe if you add acid before fermentation (hint - don't) or if you are using grapes which are naturally much higher in acid than honey then you might be closer to the unhealthy range and need the de-gassing to keep from tipping it over the edge.

I'd be surprised if wine plus carbonic acid was low enough to routinely dmage yeast though. Is degassing done every time or just under certain conditions like very acid fruit? Or very large volumes in tall tanks that would cause yeast stress anyway?

I think I'll stick to not bothering. My fermentations are always healthy and with the much lower levels of antioxidants in mead compared to wine, I don't want to run the risk. I suspect the potential for damage from o2 is much higher that the potential benefit from higher ph. In mead anyway. Wine is a whole nother game.

Cheers
Dave

 

[Vini2ton]

I made a small batch cyser once out of 4 lts of beechworth apple juice (clear) and 1kg of mallee honey. That bloody champagne yeast went birko. A month later I racked it and added 125 gm of bluegum honey for the ullage. 3 weeks later I bentonited the bugger and you should of seen the co2 coming out of it. It tasted strong and firey of alc. I thought it would be crap. 1 month later I racked off bentonite ( I know I know) and topped up with 1/2 honey solution and oak. 2 years later this is truly a complex and wonderful drink. My point is that if I had not of gently released the suspended co2 at the bentonite stage, I doubt it would of evolved into the gem it is. I've made spritzy mead before and I don't think its the go.

 

[boonchu]

Just curious Airgead, how long do your fermentations take?
I have used the degas method for a few years now have had no issues with it.
I ferment for 3 months then rack and age for 2 months then bottle.

 

[jphowman]

I had also heard that removing what dissolved gas remains at bottling time can make for a smoother mead as you're not getting a spec of carbonic acid. There must be very little left in an aged mead in any case, though.

I've made a few meads and generally age them in a secondary for 4-5 months until they clear (started doing this after the first one left a horrible fluffy layer on the bottom of the bottle that you couldn't pour off).

I've found that they all have an unpleasant roughness at the very back of my tongue. As an experiment I got a pint of the last batch and swirled the kitchen whisk through it. There wasn't a large amount of foam on the top while doing it, but slightly more than I would expect.
The roughness in the mouthfeel was reduced enough that I am considering dumping the other bottles back into a bucket and degassing before re-bottling.

 

[Mr. No-Tip]

I've made a few meads and generally age them in a secondary for 4-5 months until they clear (started doing this after the first one left a horrible fluffy layer on the bottom of the bottle that you couldn't pour off).

I've found that they all have an unpleasant roughness at the very back of my tongue. As an experiment I got a pint of the last batch and swirled the kitchen whisk through it. There wasn't a large amount of foam on the top while doing it, but slightly more than I would expect.
The roughness in the mouthfeel was reduced enough that I am considering dumping the other bottles back into a bucket and degassing before re-bottling.

Interesting. I bet the "rough" sample didn't really taste carbed? It's amazing how much gas is still left in "a negligible amount of gas"!

Have a look at "wine saver degas mead" videos. I bought one and it fits perfectly in a 5l Demi or a dry airlock. I reckon it would fit in a bottleneck too. Might allow you to degas without oxidation which the whisk is probably introducing.

 

[Airgead]

Just curious Airgead, how long do your fermentations take?
I have used the degas method for a few years now have had no issues with it.
I ferment for 3 months then rack and age for 2 months then bottle.

Primary is usually 2 weeks. if I am adding fruit I add it after primary and that usually ferments another 2 weeks. Rack and bulk age (on oak usually) for 3-6 months then bottle.

 

[Vini2ton]

Any advice about degassing elderly relatives? Phew.

 

[Airgead]

Any advice about degassing elderly relatives? Phew.

I know your pain. I wish I could help but there is no cure.

 

[Mardoo]

How about degassing 4-year olds? Dear lord my daughter can let fly. :icon_offtopic:

Anyway, back to mead...

 

[drsmurto]

De-gassing is used all the time in wine making. By GENTLY agitating the fermenting must you help get CO2 out of the ferment without introducing oxygen. This is said to help keep pH from dropping too low for healthy yeast function. In "The Jamil Show" mead show with Ken Schramm they discuss de-gassing as applied to mead.

http://thebrewingnetwork.com/shows/The-Jamil-Show/Mead-The-Jamil-Show-12-01-08

I have very little experience in this regard, and am mostly communicating what I've read and heard in 12 years in the wine industry. However my mead ferments have not gone to as low a pH when I have de-gassed.

I work in the wine industry and have never heard of anyone referring to plunging/pumpovers as degassing.There are a few reasons we plunge/pumpover, the main being to ensure the cap (grape skins pushed to the surface due to the CO2 being formed) is wet and in contact with the liquid to extract colour/tannin/polyphenols.

I think someone has taken a byproduct of this action and made it the reason.

White wines in tank are not degassed......

A quick search of the book 'Wine Science: Principles and Applications' come up with only one hit for the term 'degassing' and relates to what happens when you pour champagne in to a glass.

CO2 will slowly come out of solution during the ageing of a mead unless you are doing that in a sealed vessel. Every time you rack it you will perturb the dissolved gas and more will be released.\

I make raspberry cysers (apple juice, honey, raspberries, EC118). Never noticed any build up of CO2 but then I do rack every few months until clear.

 

[Mardoo]

The good Doctor is precisely correct. I was perhaps a bit too colloquial, or results oriented, or something. To quote one of the winemakers I spoke to about the original query, "Getting rid of the CO2 is a by-product of pumping over, but necessary." I applied this to the term de-gassing as spoken of by Ken Schramm in reference to mead, and in this thread.