Cedar Rapids Brewing Society

So I finally decided to assuage my paranoia about dissolved O2 and buy a DO meter (http://www.milwaukeetesters.com/MW600.html).

I'm trying to plan out a series of experiments to test the effectiveness of various aeration techniques and am looking for ideas. If you have any aeration/oxygenation tests you'd like me to run, let me know. After I've done a bunch of experiments, I'd be willing to lead a Tech Meeting on the topic. I have a mix-stir, aquarium pump, aeration stone, and an O2 regulator for the disposable tanks. I know a guy with an in-line aeration system & will try to test that out, too.

Excellent idea for a Tech Meeting.

Knowing the good Dr., I assume that there will be a timed component to this testing regime, in addition to varying the techniques. For example, mix-stir for 1 minute, 2 minutes, 5 minutes, and 10 minutes. Do we care about a saturation case - does each technique asymptote out to different ppms, i.e., max acheivable ppm?

Alternatively, pick a target ppm of DO and see how long each technique takes to achieve the target.

Having Lee in the club is like having your own research assistant.

I agree, it's awesome, but more like research lead! Lee, let me know when you want to do a tech meeting on this. Also, I'm willing to assist you if you need a hand. It's a topic I've got a lot of interest in as well.

On Tuesday 18 October 2011 8:47:11 am you wrote:

Having Lee in the club is like having your own research assistant.

------------------------
You can't get with this with a bad hip - Matt

Post generated using Mail2Forum (http://www.mail2forum.com)

I used my DO meter on a brew for the first time tonight. I thought you all might be interested in the following data points.

After a 90 minute boil on 6 gallons of a 1.069 IPA, I let the chilled beer splash into the fermentor and took a reading. The DO was 2.3 ppm. Next, I hooked up my regulator to a disposable oxygen bottle, opened up the nozzle completely and allowed O2 to fill the headspace for a 5 count. (Note, I did not use an aeration stone.) Then I capped the fermented and shook it for a few seconds. The DO reading went up to 6.5. I repeated the O2 headspace purge, but this time for a 10 count. After another brief shake, the DO levels registered 10.8. That seemed good enough to me, so I pitched the yeast starter.

I find it fascinating that you can hit an acceptable DO level with such a small amount of oxygen. In the past I've used an aeration stone and let the bottle run wide open for 60-90 seconds. Clearly, an aeration stone is not required and you can get away with using a lot less O2.

I have intentions of performing a series of experiments that will eventually lead to a tech meeting. Unfortunately, I've discovered that it's a real pain in the ass to actually remove O2 from water. You pretty much have to boil it for an hour to really drive out all the dissolved oxygen. As such, it's going to take me a lot longer than originally anticipated to complete these experiments.

DrPaulsen wrote:I used my DO meter on a brew for the first time tonight. I thought you all might be interested in the following data points.

After a 90 minute boil on 6 gallons of a 1.069 IPA, I let the chilled beer splash into the fermentor and took a reading. The DO was 2.3 ppm. Next, I hooked up my regulator to a disposable oxygen bottle, opened up the nozzle completely and allowed O2 to fill the headspace for a 5 count. (Note, I did not use an aeration stone.) Then I capped the fermented and shook it for a few seconds. The DO reading went up to 6.5. I repeated the O2 headspace purge, but this time for a 10 count. After another brief shake, the DO levels registered 10.8. That seemed good enough to me, so I pitched the yeast starter.

I find it fascinating that you can hit an acceptable DO level with such a small amount of oxygen. In the past I've used an aeration stone and let the bottle run wide open for 60-90 seconds. Clearly, an aeration stone is not required and you can get away with using a lot less O2.

I have intentions of performing a series of experiments that will eventually lead to a tech meeting. Unfortunately, I've discovered that it's a real pain in the ass to actually remove O2 from water. You pretty much have to boil it for an hour to really drive out all the dissolved oxygen. As such, it's going to take me a lot longer than originally anticipated to complete these experiments.

For experimentation sake I would not shake the pale or carboy, you are mixing two different form of airation by doing this.

Another good experiment to try would require a proper oxygen reg if you could borrow one. Try different pressures to see what is the most efficient flow rate for oxygenating your beer with the least amount of O2 used.

Another one would be to test different size airation stones as well as different manufacters again for the most efficient usuage.

Well, actually Lee's method is quite good. He's introducing pure O2 into the headspace then shaking to mix it into the wort. It's a direct apples to apples (pardon the pun) to doing the same with air. This method also appears to be much more efficient and easier to quantify than using a stone. Several "gurus" have stated online and on podcasts that this method is likely superior.

Lee, if it's a matter of time and manpower I would happily volunteer to assist in any way possible. Maybe by having several burners going at once we could get more tests done?


On Wednesday 23 November 2011 10:23:03 am you wrote:

For experimentation sake I would not shake the pale or carboy, you are
mixing two different form of airation by doing this.

Another good experiment to try would require a proper oxygen reg if you
could borrow one.  Try different pressures to see what is the most
efficient flow rate for oxygenating your beer with the least amount of O2
used.

Post generated using Mail2Forum (http://www.mail2forum.com)

carrisr wrote:Well, actually Lee's method is quite good. He's introducing pure O2 into the headspace then shaking to mix it into the wort. It's a direct apples to apples (pardon the pun) to doing the same with air. This method also appears to be much more efficient and easier to quantify than using a stone. Several "gurus" have stated online and on podcasts that this method is likely superior.

Lee, if it's a matter of time and manpower I would happily volunteer to assist in any way possible. Maybe by having several burners going at once we could get more tests done?


On Wednesday 23 November 2011 10:23:03 am you wrote:

For experimentation sake I would not shake the pale or carboy, you are
mixing two different form of airation by doing this.

Another good experiment to try would require a proper oxygen reg if you
could borrow one.  Try different pressures to see what is the most
efficient flow rate for oxygenating your beer with the least amount of O2
used.

Post generated using Mail2Forum (http://www.mail2forum.com)

By shaking you are inducing two forms. From what he wrote and my understanding from what he wrote. He is submerging a line into the beer and and oxygenating, which in turn fills the headspace from what does not go into solution. Then it is being shaked. In this manner you do not know how much is being absorbed by the simply putting the O2 line in the liquid and what is being introduced by shaking it afterwords.

At least that is the way I am reading what he wrote, If he is not submerging the line and only filling headspace then shaking, I agree. However, then, by doing the headspace, think in an open container you do not know how much O2 is being dispensed into the environment, as the actual headspace is a variable in brewing and dependent on how much liquid is left at the end of boil and what type of container is being used. In addition while the O2 is heavier then the Nitrogen it should still sit benneth the air, only slightly heavier then air. However, once it fills the headspace of the open container it will just flow over the side walls of the container, resulting in not knowing how much O2 is in the airspace. There may be only a small portion.

Also Lee if so inclined I would love to see some info on O2 absorbtion at different gravities and temperatures.

To clarify -- I simply inserted the barbed brass nozzle on the O2 regulator into the opening on the bucket lid (i.e. in the middle of the rubber grommet). I kept a finger near the opening and could feel air leaving the headspace. After counting to 5, I pulled out the brass nozzle and turned off the regulator. Since I was too lazy to get out my oxygen stone, my goal was to try the simplest possible means of oxygenation first, before doing something more complicated.

After filling the headspace with O2, I put my finger over the grommet/hole and shook the bucket for a few seconds. Next, I popped open the lid, sanitized the DO meter, and took a reading.

One thing to note is that I have no idea if the oxygen was uniformly distributed, since I just measured the wort near the top of the bucket. I presume the shaking mixed it up pretty well. Also, whatever I did seemed to work, since I had a very active fermentation this morning, even though I set the fermentation chamber at 62F.

On Nov 23, 2011 12:35 AM, "DrPaulsen" <brew-equipment@crbeernuts.org (brew-equipment@crbeernuts.org)> wrote: > > Unfortunately, I've discovered that it's a real pain in the ass to actually remove O2 from water.
Lee, you just need to make your water from scratch*. Take a glass carboy and fill it with hydrogen. Then add enough oxygen to displace 1/3 of the hydrogen. Seal the carboy and wait a short while for the two gasses to mix. Then introduce a small spark.
At this point, you won't have any worries about dissolved O2 in the resulting water. In fact, you probably wont have any other worries!
The only downside I see is that you'll need to find someone else to lead the meeting....
*Disclaimer: This should only be attempted by people with a thorough knowledge of chemistry, and a desire to die in a spectacular but meaningless fashion.

Post generated using Mail2Forum (http://www.mail2forum.com)

Just make sure it's a glass carboy. We wouldn't want to deal with any pesky witnesses.

For what it's worth, Lee, The USP defined carbon dioxide free water as water that has been "boiled vigorously for 5 minutes and allowed to cool in a covered vessel" I;m not sure if oxygen has a higher affinity for water, but this was the method we used in the lab. The other method we used was putting solutions under vacuum and sonication for 30 seconds, but that doesnt work too well in the home lab.

Perhaps we could actually do some of the experiments for a tech meeting. We could bring over burners/kettles/chillers/fermenters and do a lot of the work in parallel. Just a suggestion -- it's not my garage.

Tom -- that is a genius idea and should be coordinated.

OK, let's do it. Let me know what dates are available and I'll put it together. Are you willing to host Lee?


On Thursday 24 November 2011 7:07:23 pm you wrote:

Tom -- that is a genius idea and should be coordinated.

Post generated using Mail2Forum (http://www.mail2forum.com)