All You Ever Wanted to Know About Oxygenation

[Bassman2003]

Thanks for this thread. Great information about Oxygen tanks.

The topic of oxygen and pitch rates is being talked about on another forum and I have come to the conclusion that this is an important strategic step for planning how your beers turn out.

For my next hefeweizen I am going to try making a 2L starter (with plenty of O2) along with barely adding any oxygen before pitching for the 5-gal batch. I would like to emphasize esters with this style and am wondering if this method might make a difference - pitching a lot of yeast in a low O2 environment.

This seems safer than underpitching.

 

[TrickyDick]

I wonder if, when using a dissolved oxygen meter, if there is any importance on how long to wait between aeration and measurement? I am wondering specifically, if taking a reading immediately after removing the oxygen wand is going to be spuriously high. What are the commercial brewers doing, and do they measure the oxygen levels?

TD

 

[orangehero]

The big guys inject and measure inline. It's very expensive gear, so I would guess small breweries just measure time and/or flowrate and then adjust depending on fermentation performace. That's the approach I go by at least.

 

[TrickyDick]

How about the not so big guys?

 

[dstar26t]

It's not the time between oxygenation and measurement that's important. It's the time between measuring your target DO and pitching that you need to minimize. Oxygen comes out of solution quickly, you want your yeast to get as much of what you measured as possible for consistency.

 

[jaw94087]

I didn't see anywhere in the thread where the data from White's Yeast book for aeration using o2 is reported. On page 79 from the book, it is reported that the author's measurements with 5.3g of 1.077 wort using .5 micron stone with a 1 LPM flow rate yielded 9.2 ppm for 60 seconds and 14.02 ppm for 120 seconds. Personally, I have followed these guidelines. The formula from the OP seems to be significantly different from this book's recommendation.

 

[drunkenmonk]

I didn't see anywhere in the thread where the data from White's Yeast book for aeration using o2 is reported. On page 79 from the book, it is reported that the author's measurements with 5.3g of 1.077 wort using .5 micron stone with a 1 LPM flow rate yielded 9.2 ppm for 60 seconds and 14.02 ppm for 120 seconds. Personally, I have followed these guidelines. The formula from the OP seems to be significantly different from this book's recommendation.

dstar26t posted some measured data which I did a new curve fit to in a previous post:

ppm = (8.4905 * LPM * minutes aeration time) / gallons wort + 7.9254

The curve fit is so-so and it doesn't have a zero intercept (i.e. you get PPM oxygen with no oxygenation). That said, it does an okay job at matching the data from White and Zainasheff. Where they predict 9.2 ppm, this equation predicts 9.5 and where they predict 14.0 ppm, this equation predicts 11.1. If you include this data, the equation changes slightly to:

ppm = (8.4294 * LPM * minutes aeration time) / gallons wort + 8.1019

I'll update the original post to this. It's not perfect as it ignores factors such as wort temperature, OG, saturation, etc. but it gives you a rough number to shoot for.

 

[renthispace]

I have the Williams brewing wand and 'regulator' system for the bernzomatic tanks. Can someone with a real regulator and the same 2 micron air stone give some general observations for different flow rates? I've always turned it on just enough to get a decent stream of bubbles cresting the surface but the regulator can go much higher. What does 1 lpm or 3 lpm look like?

I've always aerated for 30 seconds as I recall reading somewhere that this was more than enough time for adequate aeration. I've never liked that answer and always wanted a DO meter to do exactly what you are doing. I applaud your effort OP.

 

[TrustyOlJohnson]

Alternatively.... for thrifty people.

Shaking or an aquarium pump provides basically perfect aeration for everything other than big beers. 8ppm. It actually is a quite controlled process since you saturate at 8ppm.

An initial aeration followed again in 8 hours provides the perfect levels for most big beers. 8ppm+8ppm = 16ppm

So, if I want to go this route, what "size" of aquarium pump are you using and how long do youe aerate to get 8 ppm??

 

[FatsSchindee]

I forget if it was mentioned earlier (I remember seeing a pic someone posted), but what flow meter have you guys found to be useful to work with your airstone O2 systems? I received a fermentap O2 system with a 0.5 micron stone for Xmas, and just picked up an O2 bottle from HD. So I can just adjust flow and time it, like some have said they do, but I too would rather see a flow value and be able to replicate that for a certain amount of time each batch.

So what model is the best for is kind of set up (something in-line with barbs attachments for the tubing, I assume?). Is it the pediatric models that to from 0-4 lpm? That seems to be the best for the low flow rates I see recommended. Thanks for any advice!

 

[drunkenmonk]

So, if I want to go this route, what "size" of aquarium pump are you using and how long do youe aerate to get 8 ppm??

An aquarium pump will take about 5 minutes. Here's a comparison of methods such as shaking, oxygen, and pumps done by Wyeast: http://www.wyeastlab.com/hb_oxygenation.cfm

 

[drunkenmonk]

I forget if it was mentioned earlier (I remember seeing a pic someone posted), but what flow meter have you guys found to be useful to work with your airstone O2 systems? I received a fermentap O2 system with a 0.5 micron stone for Xmas, and just picked up an O2 bottle from HD. So I can just adjust flow and time it, like some have said they do, but I too would rather see a flow value and be able to replicate that for a certain amount of time each batch.

So what model is the best for is kind of set up (something in-line with barbs attachments for the tubing, I assume?). Is it the pediatric models that to from 0-4 lpm? That seems to be the best for the low flow rates I see recommended. Thanks for any advice!

I initially set out to find an in-line flow meter, but they're hard to find and pricey; especially at low flow rates. I ended up buying a regulator that controls flow rate for only $48. That's probably not good advice since you just got your fermentap system.

 

[FatsSchindee]

I initially set out to find an in-line flow meter, but they're hard to find and pricey; especially at low flow rates. I ended up buying a regulator that controls flow rate for only $48. That's probably not good advice since you just got your fermentap system.

Yeah, I know it will cost more in the long run buying the benzamatic o2 canisters, but SWMBO already thinks my brewing equipment takes up too much room in our house, so decided not to go with the big old o2 cylinder for now...

 

[renthispace]

I have the Williams brewing wand and 'regulator' system for the bernzomatic tanks. Can someone with a real regulator and the same 2 micron air stone give some general observations for different flow rates? I've always turned it on just enough to get a decent stream of bubbles cresting the surface but the regulator can go much higher. What does 1 lpm or 3 lpm look like?

I've always aerated for 30 seconds as I recall reading somewhere that this was more than enough time for adequate aeration. I've never liked that answer and always wanted a DO meter to do exactly what you are doing. I applaud your effort OP.

Anyone want to make a YouTube video?

 

[maltoftheearth]

How much are the bottles of O2 at a hardware store typically? Trying to decide whether investing in a larger setup is worthwhile as a long term investment ...

 

[eastoak]

How much are the bottles of O2 at a hardware store typically? Trying to decide whether investing in a larger setup is worthwhile as a long term investment ...

those cylinders were somewhere between $15-20 around here if i remember correctly. my O2 cylinder and regulator were around $120-130 at harbor freight a couple of yrs ago and i've yet to refill the cylinder (it's the 20 cubic foot size)

 

[butterpants]

Benzomatic O2 cyls are 9$ here. I've been using the same one for 13 batches.

Sent from my Galaxy Nexus using Home Brew mobile app

 

[renthispace]

Anyone know about disolved oxygen test kits vs meters? There are a lot of different test kits that are much cheaper than the electronic meters. Obviously the question is how accurate are they?

http://www.amazon.com/s/ref=nb_sb_ss_sc_0_9?url=search-alias%3Daps&field-keywords=dissolved%20oxygen%20test%20kit&sprefix=disolved+%2Caps%2C472&rh=i%3Aaps%2Ck%3Adissolved%20oxygen%20test%20kit

I think it would be beneficial to always know the DO as there will always be variables at work that will effect a given flow rate and time. I would like to find that 'average feel' of time vs flow that will always leave me slightly over oxygenated, and then never really test again (testing for pH and gravity is enough for me on a normal basis). My previous notion of 30 seconds is long enough just doesn't work for me anymore.

 

[RodimusPrime98]

Are any of the original 2013 posters to this subject still monitoring?

I am curious if anyone can share the data that dstar26t posted here:
https://www.homebrewtalk.com/thread...to-know-about-oxygenation.414616/post-5465938
The first post of the thread I believe is up to date with the following formula:
time = 0.113 * (volume / flow rate) * (ppm - 8.1019)

Then in post All You Ever Wanted to Know About Oxygenation, this equation is provided:
ppm = (8.4905 * LPM * minutes aeration time) / gallons wort + 7.9254

If I solve that equation for time I get:
(minutes aeration time) = ((ppm-7.9254)*(gallons wort))/(8.4905*LPM)

If I assume the follow inputs:
LPM (aka flow rate) = 0.5
Gallons of wort (aka volume) = 6
PPM = 14

I get the following:
time = 0.113 * (volume / flow rate) * (ppm - 8.1019) = 0.113*(6/0.5)*(14-8.1019) = 8 minutes
OR
time (aka minutes aeration time) = ((14-7.9254*6))/(8.4905*0.5) = 8.6 minutes

I just performed a test using the equation:
Time = 0.113*(volume*LPM)*(ppm-8.1019)
which using the inputs above gives:
Time = 0.113*(6*0.5)*(14-8.1019) = 2.0 minutes

Using a Dissolved Oxygen meter I found dosing for ~2 minutes yielded ~12ppm of additional O2 with the parameters listed above. This leads me to wonder how another formula based on test data could recommend 4 times the duration of O2.

Thank you!

dstar26t posted some measured data which I did a new curve fit to in a previous post:

ppm = (8.4905 * LPM * minutes aeration time) / gallons wort + 7.9254

The curve fit is so-so and it doesn't have a zero intercept (i.e. you get PPM oxygen with no oxygenation). That said, it does an okay job at matching the data from White and Zainasheff. Where they predict 9.2 ppm, this equation predicts 9.5 and where they predict 14.0 ppm, this equation predicts 11.1. If you include this data, the equation changes slightly to:

ppm = (8.4294 * LPM * minutes aeration time) / gallons wort + 8.1019

I'll update the original post to this. It's not perfect as it ignores factors such as wort temperature, OG, saturation, etc. but it gives you a rough number to shoot for.

 

[Vale71]

Using a Dissolved Oxygen meter I found dosing for ~2 minutes yielded ~12ppm of additional O2 with the parameters listed above. This leads me to wonder how another formula based on test data could recommend 4 times the duration of O2.

This just shows that there are more variables involved than those accounted for in the formula (i.e. flow rate, volume and time). In other words the formula is useless.

 

[day_trippr]

I suspect wort density also plays a role, if only because when I was carbing "thick" stouts pre-beergas days they took a lot longer to reach ~ 2 volumes than a pale or even IPA.

iirc, Chris White's Yeast benchmark O2 metric was 2 minutes at 1 lpm. When I picked up an O2 tank and medical flow meter rig I went with .5 lpm for 4 minutes stirred in with a Williams .5 micron wand. And while I don't adjust for OG it still seems to work well enough...

Cheers!

 

[Vale71]

I suspect wort density also plays a role, if only because when I was carbing "thick" stouts pre-beergas days they took a lot longer to reach ~ 2 volumes than a pale or even IPA.

iirc, Chris White's Yeast benchmark O2 metric was 2 minutes at 1 lpm. When I picked up an O2 tank and medical flow meter rig I went with .5 lpm for 4 minutes stirred in with a Williams .5 micron wand. And while I don't adjust for OG it still seems to work well enough...

Cheers!

Did you take measurements with a DO meter? If you didn't then you have no idea whether your system gives you optimal DO levels or not.

There are many factors that will influence the actual yield, i.e. how much of the O2 that flows out of the bottle will get dissolved, so that determining yield mathematically is really a complex problem. We have wort viscosity. which you already indirectly addressed, but also temperature (lower temperature means lower diffusion rate) as well as aeration stone and fermenter size and geometry.

Alternately one could take a series of measurements (actual measurements being key here) and determine approximate yield values for his setup under the most frequently occurring conditions which might give good predictions as long as no major changes in equipment and setup occur. If you try and use those values for a different system the results you will get will most likely be completely useless, i.e. either leading to systematic over-oxygenation or under-oxygenation.

 

[day_trippr]

Did you take measurements with a DO meter? If you didn't then you have no idea whether your system gives you optimal DO levels or not.[...]

In fact I had a borrowed Milwaukee DO meter for almost a month back in the pre-LoDO days and did some testing with it. The method I described peaked at 12ppm in the carboy with most worts (I typically brew in the 60-65 point range) then rapidly fell as the yeast went to work and some portion no doubt escaped towards the 8ppm atmospheric partial pressure. I got about as much as I needed to see what White was seeing, I believe...

Cheers!