degassing question.

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tom_gamer

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So I starting to ready up on my mead making technique and I think the next thing I will need to do is degas. My question is, aren't people worried about oxygen? I know that with beer everyone is always worried the air touches the beer. How is mead different?
 

GinKings

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Brewers are usually worried about oxygen after fermentation ends. Oxygen is beneficial during the earlier stages of fermentation for both beer and mead. Most brewers and meadmakers oxygenate when they pitch their yeast. Many meadmakers will oxygenate a few more times until 1/3 of the sugar has been consumed. After that, everybody tries to minimize oxygen.
 
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The 1/3 rule is probably what I am thinking of. This would explain my concerns.

So the only real way of know when you have reached the 1/3 is by a hydrometer reading right?
 

fatbloke

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The 1/3 rule is probably what I am thinking of. This would explain my concerns.

So the only real way of know when you have reached the 1/3 is by a hydrometer reading right?
To prevent confusion, at this stage, its not de-gassing, it's aeration. The object of the exercise, is to add air/O2 for yeast development. The removal of CO2 is a side effect of stirring/agitation.

But yes, the only way of ascertaining the 1/3rd break is hydrometer readings.

A clearer explanation can be found in the gotmead NewBee guide (linked at the left-hand dialogue/links box on gotmead forums main page).
 
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tom_gamer

tom_gamer

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fatbloke said:
To prevent confusion, at this stage, its not de-gassing, it's aeration. The object of the exercise, is to add air/O2 for yeast development. The removal of CO2 is a side effect of stirring/agitation.

But yes, the only way of ascertaining the 1/3rd break is hydrometer readings.

A clearer explanation can be found in the gotmead NewBee guide (linked at the left-hand dialogue/links box on gotmead forums main page).
I'll have to check it out. I got the compleat mead guide coming in the mail. So I can't wait for that.

What is degassing? Opposed to aeration
 

haxcess

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What is degassing? Opposed to aeration
Just like we breath out CO2 and can't breath it back in, the CO2 is toxic for yeast. Not toxic like anthrax, just that they do better without swimming in their own farts.

Basically, the yeasts are carbonating your must to a mild degree. Enough that if you seal some in a bottle and shake it up, you will have a pressurized bottle.

I didn't believe it either.
 
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tom_gamer

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haxcess said:
Just like we breath out CO2 and can't breath it back in, the CO2 is toxic for yeast. Not toxic like anthrax, just that they do better without swimming in their own farts.

Basically, the yeasts are carbonating your must to a mild degree. Enough that if you seal some in a bottle and shake it up, you will have a pressurized bottle.

I didn't believe it either.
So do you degas after the 1/3 rule? Because I heard you're supposed to degas till there is no more CO2 left.
 

haxcess

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Personally I'm really hands off. I swirl my batch around to degass during primary but I don't remove the airlock ever, much less take samples and stick stuff in it.

I swirl my carboys around and the airlocks start bubbling like crazy, I stop when the airlocks really slow down. Takes about a minute.
 

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So do you degas after the 1/3 rule? Because I heard you're supposed to degas till there is no more CO2 left.
After the 1/3 rule, you don't degas anymore. Well, that's not entirely correct. You shouldn't have to degas anymore. Degassing is far more common in kit wines that are rushed to bottle while meads tend to sit around longer to age in the carboy. Over time, the mead will degas as it sits. If the mead is still gassy when it is bottled, at that time, it is degassed- usually by stirring. I've never had to degas a mead though.
 

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The Compleat Meadmaker is a great book, but it is getting a little dated. So, it may not contain some of the newer procedures, such as aerating until the 1/3 break, staggered nutrient additions, etc.

Basically, aerating is adding oxygen and degassing is removing CO2. Prior to the 1/3 break, it may be technically called aeration, but you are usually doing both when you stir/agitate your mead. I'm no expert, but once fermentation begins, the mead is saturated with CO2. I don't see how you can effectively aerate the mead without removing some CO2. While neither is an absolute necessity after fermentation begins, both adding oxygen and removing CO2 are beneficial in the early stages. After the 1/3 break, leave it alone. I believe degassing after fermentation is done by some winemakers. I don't know any meadmakers that do it (not that that means much).

The 1/3 break is usually considered the stopping point for aeration (or degassing). Personally, I just guesstimate when to stop. Taking a hydrometer sample every day is a pain and it can increase risk of contamination. If I expect a two week ferment, then I aerate for the first four days. I figure it won't make a huge difference whether I stop at the 1/4 or 1/3 sugar break.
 

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The Compleat Meadmaker is a great book, but it is getting a little dated. So, it may not contain some of the newer procedures, such as aerating until the 1/3 break, staggered nutrient additions, etc.
Kens book is indeed excellent - especially for you lot over the western side of the pond! It'd be great if it was possible for it to be a little more international i.e. regional variations in some of the ingredients mean that I can only really use it as a bit of a guide - some of his recipes sound wonderful, but you just can't find/don't see some of the ingredients. Plus we don't see the extensive range of varietal honies. Yes there's some varietals, but not anywhere near as many as you lot seem to have access too (could be something to do with EU regs etc, I don't know)
Basically, aerating is adding oxygen and degassing is removing CO2. Prior to the 1/3 break, it may be technically called aeration, but you are usually doing both when you stir/agitate your mead. I'm no expert, but once fermentation begins, the mead is saturated with CO2. I don't see how you can effectively aerate the mead without removing some CO2. While neither is an absolute necessity after fermentation begins, both adding oxygen and removing CO2 are beneficial in the early stages. After the 1/3 break, leave it alone. I believe degassing after fermentation is done by some winemakers. I don't know any meadmakers that do it (not that that means much).
Now that, is exactly the point I was trying to convey. Because using the appropriate term, may seem like semantics, but it also conveys the exact stage of the "making process". The whole point of this part of the process, is less about stopping any of the CO2 escaping - it does that naturally (Boyles law and all that), whereas the agitation of the must to a set point (using the 1/3rd break - because that seems to be the point that most people use), allows air/O2 into the must to aid yeast cell development.
The 1/3 break is usually considered the stopping point for aeration (or degassing). Personally, I just guesstimate when to stop. Taking a hydrometer sample every day is a pain and it can increase risk of contamination. If I expect a two week ferment, then I aerate for the first four days. I figure it won't make a huge difference whether I stop at the 1/4 or 1/3 sugar break.
I suspect that this point is to do with making a recipe, using a certain technique, repeatable i.e. guesstimates can be wildly out, despite only minor changes to a recipe and the method used. Plus it starts to create some sort of basic standards (god alone knows, that with most mead making there are few enough standards). Of course, they're not set in stone.

Home brewers, particularly people who've done beers, seem to be obsessed about possible contamination. Probably, rightly so. Yet I use hot, tap water to wash and rinse my hydrometer, test jar and turkey baster, then before use, I spray everything with home made sanitiser (5 campden tablets crushed, 1 teaspoon of citric acid - mixed into 500mls of water - which is kept in a household hand sprayer), allowing for 2 or 3 minutes of contact time. I've yet to have any contamination. The early stages of primary fermentation are, I understand, very good at killing off the kind of stuff that will cause contamination of a brew, and it seems that what I do on top of that is enough. It only takes me 5 or 10 minutes to make the test.....

Using the 1/3rd break is probably less important with lower, more easily managed, gravity musts (probably something like the 1.100 area), but it does seem that a lot of people your side of the ponds like to work on the basis that if the yeast is capable of 18% ABV, then that's what they want - which equates to a 133 point drop in gravity - or if they work out that they want to have X amount of residual sugars as well, they will mix a must in the 1.140 to 1.150 area, which to my mind at least, is incredibly high and subjecting the yeast to conditions that mean it's starting to stress - possibly with no obvious issues, but they then complain when the must sticks at 1.050 etc and they also find it a bit of a bugger to restart a must that already has an alcohol content IRO 13.5%.

I'll have to check it out. I got the compleat mead guide coming in the mail. So I can't wait for that.

What is degassing? Opposed to aeration
De-gassing is exactly what it sounds like. A lot of the commercial beer makers diliberately add the CO2, not just because it makes it easier to serve/pour, but because when the CO2 is in solution, it's there as carbonic acid (a weak organic acid) that adds a little bit of acidic bite to the taste - when they tell us (through adverts/marketing) that's what makes it "refreshing", we, like total sheep, believe them. Think on the type of beer that is normally quite carbonated, then think of the difference between beer that's still bubbling in a glass and an identical one that has gone flat, then think of the difference in taste between the two.

Most beers, aren't meant to be sweet, so that slight bit of acidic bite is part of what we expect.

With meads, specifically (though the same can also apply to wines), one of the things that we don't notice so much, is that honey is quite acidic, but we dont' notice that because of the huge levels of sugars that mask that part of the taste - though you only need to take a pH reading of a must, pre-fermentation, to see how it is (generally speaking). Some of the best meads have very clear, obvious, honey like profiles, just not the mega sweetness of pure honey - the sugars have become alcohol after all and I don't know how you could describe the taste of high % ethanol in words.

Anyway, by carrying out a de-gassing stage of a finished ferment, you're removing any part of the taste that can be attributed to CO2, whether it's bubbling out, or in solution. Some vineyards/wineries will de-gas, others not. If I open a bottle of wine, I'll usually taste it, then see if I can de-gas it some, by using my "Vacuvin". If there's any bubbles showing when the Vacuvin has been pumped, then I pump it a couple of times, and then taste again. The difference can be amazing.

Personally, I like to aerate my batches to the generally accepted 1/3rd break, then let them finish dry (I mix my batches to about the 1.110 area, so they'll generally be in the 14% + region). Once finished, I will rack them off the gross lees and stabilise them - then take a gravity reading. I like my meads at about 1.010 - sweet enough for me - and because I like to back sweeten with honey (and knowing it can cause a haze in cleared batches) I then back sweeten it to the required level with a 50/50 honey and water syrup. Then I clear them, either with just time, or if I'm feeling a bit impatient, I'll hit them with finings. Then just leave them to age, a minimum of 6 months, but usually a year plus.

When it's time to bottle, I will then de-gas, either with my enolmatic or my mini-jet (you can also use a mityvac brake bleeding pump - just the pump and piece of tube through an airlock bung). It's amazing to learn just how much CO2 is still in solution. Then it's taste time. If the batch tastes like it needs a tiny bit of acid bite, I'll add that with a mix of 2 parts malic, 1 part tartaric. I'd rather the taste of intentionally added fruit acids than the carbonic acid - which has a bland, non-descript taste. The only time I want carbonic acid/CO2 present in the finished product, is if it's supposed to be sparkling/bubbly.....

Sorry if that sounds like I'm rambling on, but it's the only way I can think of to convey the point......
 
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