What should I need and what should I want
- Thread starter lozoot
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We also have to remember that o2 is driven out of wort during the boil. This of course is why we have to aerate it.And then of course,we have oenning the fermenter for SG readings,etc.
This I think starts the process over again,but to a smaller extent. Depending of course on how much one openns the fermenter as it gets closer to FG. This is how **** happens...
Well effectively the boil is going to drive off all the O2, randomness says it should leave some, but not much. I'd guess our tap water has no more than about 4ppm.
A quick look at some sources having to do with landscaped water features has the pre dawn O2 levels at about 4ppm -plants having consumed the free O2 during the night. It is interesting becuase this is what we can stir into things, which indicates that is the 'saturation level' that can be obtained from forcing O2 in at the surface, but again, I'd like to see some numbers. (at some point for every bit of O2 you stir/shake in, you sitr/shake it out)
The yeast use the O2 for making more yeast (sterol production for cells) and for general energy usage - ie making Sugar into CO2 and H20. And everytime we open up we put some more O2 back into the fermentor, and possibly a lot, if we give a good accidental mix of the air and head space.
Personally I don't worry about this, it sits for 3 weeks, and then goes to bottle, so there is little time for new O2 to get introduced. I don't bother with they hydrometer on most recipies anymore.
n240sxguy
Well-Known Member
unionrdr said:
I do 10 gallon batches in a conical fermenter that is rated at 15 gallons, but actually holds around 18. That's my basis for headspace doesn't matter as long as the air isn't swirling above the wort introducing o2 directly to it.
Lozootmaniac
Well-Known Member
i know. Try to read it through. I wish people didn't jump into a thread and start saying,
These guys didn't contribute. Thanks to all for cool responses and even the critic of my experiment that actually taste like biscuits with honey and jelly on them. It stinks though.
I'm going to use this bucket and get an airlock. Then I'm only going to purge if the beer I make tastes funny and I suspect it was o2, when I remake I'll purge the fermenter.
Apparently I can make as much or as little as I want in the bucket, as long as it isn't less than an inch from the top.
Oh... I see what you're trying to say. I was confused because the word "absorbed" isn't used for the process you're describing.
What you mean to say is something like this, "As the CO2 is produced, it mixes with the O2 already in the headspace. Both O2 and CO2, being gasses, exert a pressure on the container they are in. According to Dalton's Law of Partial Pressures, the total pressure of the resulting mixed gas is equal to the sum of the partial pressures of O2 + CO2. Thus as the pressure of CO2 rises, the total pressure in the headspace rises. Once the total pressure exceeds the downward atmospheric pressure on the airlock, you see bubbles."
But I'm sure that's what you meant, given that you got "A's" in science and all...
Yup. But by the time I got to collegein the early 80's,commII taught us to write the way we speak. IE,less formal,flowery language. It will then be easier to assimulate by the average reader. no need for science speak,in other words...To the others,it reads like we have an accord...
I have to laugh at this... you wouldn't understand why, but it's funny to me... One of the more interesting aspects of dealing with forums on the Internet is that you often have no idea who you are dealing with, or what their qualifications and skills are.
With that said, I'm going to go giggle to myself over a beer. Have a great night my friend.
I do not see how CO2 absorbs O2. CO2 and O2 are unreactive and will not combine into CO4 or any such like that. Sure, in a large enough container CO2 and O2 may stratify some but you would have a level between where there is a mix of the two gasses which in the small amount of headspace in a fermenter will pretty much be the whole headspace of the fermenter.
Warning. Math below.
During peak fermentation the CO2/O2 mix would be under enough pressure that the O2 would be diluted to near insignifigant levels by the sheer amount of CO2 produced by the frmenting wort. See the first post in this thread. Using the example from that post (113.8 Liters of CO2 per gallon of wort from a 1.055 OG wort with 75% attenuation), if there are even 2 gallons of wort in a 6.5 gallon bucket, the 227.6 Liters of CO2 should be more than enough to dilute and push the remaining O2 from the fermenter to negligible levels. Especially since the vast majority of fermentation activity happens within the first 2-3 days after the yeast gets to work.
</Math>
Warning. Math below.
During peak fermentation the CO2/O2 mix would be under enough pressure that the O2 would be diluted to near insignifigant levels by the sheer amount of CO2 produced by the frmenting wort. See the first post in this thread. Using the example from that post (113.8 Liters of CO2 per gallon of wort from a 1.055 OG wort with 75% attenuation), if there are even 2 gallons of wort in a 6.5 gallon bucket, the 227.6 Liters of CO2 should be more than enough to dilute and push the remaining O2 from the fermenter to negligible levels. Especially since the vast majority of fermentation activity happens within the first 2-3 days after the yeast gets to work.
</Math>
Hey,I didn't come up with the science,it's just how this friggin argument went when the shoe was on my foot. Now it's the other way around & people are changing there minds & ranking me. I'm not the "troll" here. It is what it is. Math is like surveys,they can be used to prove anything. Practice can be quite different. The math can't be counted on to be 100% correct 100% of the time. Deal with it.
I am not calling you a troll Union. I am just stating things as I see them, and what my experiences have yielded. The math was just to back up my opinions. That is the beauty of the internet and this forum. It is a place to share what you know/suspect and learn from it.
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