Read this about aeration. Better mead making techniques!!!

This is a note I sent to another forum member and thought we all would benefit from this info!


I am by no means an expert on any of this. I am how ever a earnest reader and devour everything I can find on things attached to passion.

One of the best books I have read is Yeast The practical guide to beer fermentation. By Chris White (White labs) and Jamil Zainasheff Both are PhD's and in the book everything is footnoted to scientific publications. This is the stuff I love. It's not guys who think they know things. It's lab coats who have devoted their entire life to the scientific study of, in this case, beer/whine yeast.

So the piece I sent you from Morebeer said, (and I have seen this same info in other places) tells us yeast in fact do not need O2 to make alcohol. They resperate either way. The reason they do so much BETTER with O2 is it helps them to build the proper cell wall and sets then up to withstand the toxic environment in the latter phases of fermentation.

So in the book they have an entire chapter on fermentation, Duh!

The section about O2 supplementation tell us what I am now about to relay to you. After much studies (from the authors as well as other scientific journals) they have determined the proper amount of dissolved O2 in a must for beer must (as you know much lower than mead must) Beer gravities need 8-10 parts dissolved O2. Of course higher gravities need more yeast which in turn need more yeast = more O2 still. Mead must are best suited with 12-15 ppm.

Must splashing devices such as carboy splashing/sumo wrestling supply approximately 4 ppm. With very aggressive shaking one might be able to bring this total up to 8 ppm. Even using an aquarium pump or drill attached lee's strirer for extended times will still only get you to 8ppm. The only way to get higher is to use pure bottled oxegyn and a .5 micron sintered stone.

To help homebrewers White Labs did an experiment injecting pure O2 into 20L/5.3 gallons of 1007 gravity using a .5 stone. At a flow rate of 1 ltr per minute the results are as such,,,,,,shaking for 5 minutes 2.71 ppm, 30 seconds pure O2 5.12 ppm,,, 60 secs pure O2 9.20, 120 seconds 14.08.


If we have a must with a higher gravity of 1083 we must aerate with pure oxygen > Not only do we do as advised above we also have to aerate a second time. A second dose between 12 and 18 hours can help speed and attenuation. The yeast quickly takes up this oxygen and uses if for cell membrane maintenance and the production of some needed intermediary compounds. Research also indicates the addition of oxygen between 7-12 additional ppm at 12 hours increases fermentation speed by as much as 33% and decreases flavor compounds such as diacetyl and acetaldehyde. Why wait for 12 hours? You are waiting for yeast to make at least one cell division. There is no additional benefit before the yeast has had a chance to divide at least once.

Above 100 you might chose to adjust your pitch rate to 35 million cells per millimeter. At 48 hours you can also raise the temps just a couple degrees to keep your yeast working at a maximum. AT this point most of the flavor compounds have already been made and a small raise in temps will not affect the flavor profile but will help the yeast finish strong.



-----Original Message-----

It's no surprise your the first to respond. I love that curious minds want to understand what we are doing when we make mead. I too am always hungry to make the very best mead I can.

You have great points and I'm not sure I really know the answers. As I began in my post I am not and educated expert. But rather a hungry, self taught reader. I guess unless we have the opportunity to be the guys in the lab coat starring through polished glass the best we can do is rely on what they tell us is true. And yes, when we read thier info and have questions we can only try to understand what they say in context to the report.

So this is now what I offer, possibly a way to try to understand their stuff in context.

I re read your link several times so as to not miss something. Here is the quoted pertinent statement.

The infusion of pressurized pure oxygen into wort
is undoubtedly another effective means of raising
the wort oxygen content. However, there are
added costs associated with the use of pure
oxygen, and there is some risk of toxicity to the
yeast from over-oxygenating wort. Saturating wort
with pure oxygen is likely to be toxic to the yeast.
Thus, some means of monitoring the oxygen
content of the wort or of controlling the amount of
oxygen delivered to the wort would appear to be
necessary. Testing the relative effectiveness of
aerating with air versus pure oxygen would be a
reasonable and useful addition to experiments
presented here.

So the writer says there might be some risk of toxification. He doesn't seem to know for sure, but only assuming there could be some risk and that could be a place for further study. Chris White has spent a good bit of time visiting breweries and testing the O2 parameters of these breweries. Many times to help them to get things on track. He did state that too much O2 in beer "can be detrimental to head formation and retention.

He then went on to say "the only way to reach the 10 ppm is with the addition of oxygen. Later in the chapter he was also the one who recomende adding the additional does of oxygen at the 12 hour mark. I have also read this very thing in a Lallemande piece Lehnard Cohn wrote refering to this additional aeration in the wine business as a pretty standard procedure.

When they tested the vigorous shaking method in a 5 gallon carboy they observed a 2.71 ppm level at 5 minutes. Admittedly, I do not know how to interpret the % of saturation in the link you provide, to be able to translate that to ppm. I'm sure one could find that answer very quickly with Google. I'm trying to get this off to you before heading out to the salt mine this morning.

So with information I posted, I can only suggest what I think was the line of thought in regards to the addition of O2 at the 12 hour mark. Assuming most of the scenario's Mr White deals with prohibit shaking multi-barrel vessels for obvious reasons. We can surmise the one time addition at the 12 hour mark would be x hours post lag so that all of the yeast, including the late budders, would have split. This would ensure that all of the yeast would be recipients to the O2 addition.

He was the one who then suggest to add the amounts of additional O2 at the rates I wrote in the opening piece. They have graphs showing speeds of fermentation and attenuation rates with different amounts of O2 to support the "best" additions based on kenetics. I don't know about toxicity but I'm sure he does and would not suggest in his book to add X amounts knowing those metrics would be toxic. I would image if the rates of additional O2 we toxic you would see that in the graphs, rather than "best performance" results.

I get it that you have bigger challenges where you live. I live in a wonderful location that makes my temp control super easy to stay within 2 degrees the whole time with almost zero adjustments.

The fix here with oxygen is very affordable. You can buy these things,,,, https://www.morebeer.com/category/wort-oxygenation-aeration.html along with this ,,, http://www.homedepot.com/p/Bernzomatic-1-4-oz-Oxygen-Gas-Cylinder-304179/202044702

FYI. I just made a pyment with cab concentrate using my methods and the yeast chewed through 20 points a day at temps just 2 degrees above the lower end of the tolerance window. It's only at 1020 now but it has zero off flavors. I don't have a side by side comparison but I have been using O2 for a while now and with the O2/Goferm/ Fermaid O/ temp controls protocols all in order I have never made such good meads. The last 30 gallons or so have been quite drinkable even before they clear. I now filter my stuff, and have had one high ABV batch have a bit of alcohol heat early on but as soon as my oaking started to calm that it has become one of my favorites.

Please reply

Yes I can confirm they are talk pure O2. They said that with the first hour all the O2 added prepitch is gone already

It's nice to hear someone actually likes to read this type of thing. So often when I post up science stuff only the same few people join in. It's really meant to help raise the bar for all of us.

EvolvingCaveman said:

Good information, Squatchy.
I have on my project list to build a stir plate large enough to do a 5 gallon bucket.
I though about alternating between running the stir plate and an aquarium pump
until the 1/3 sugar break.

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According to the book you can't get more that 8% with an aquarium pump. The same as what I would tend to believe your stir plate would provide. They don't require oxygen to make alcohol. Huge misnomer here. They can make it on their own. The cell wall is made much heartier when they have it in the prescribed phases of their life line.

Thanks brother. I appreciate the comment and I appreciate your involvment in the forum as well!

pokerfacepablo said:

Great points being brought up here. Also curious if this will pertain to wine yeast since the studies are done with beer yeast and wort. Hopefully it won't pertain to wyeast 1388... I love my BOMMs.

I recently received an oxygenation kit and used it on 2 batches. I had it dialed high which caused the disposable tank to run dry fairly quick. Might purchase a 5lb tank to bring down the longterm cost. Anyway, no major off flavors with oxygen wand. I used only wine yeast so far. D47 and Wyeast 4767 (fortified wine yeast). I used the wand twice a day for the first 1/3 sugar break. Both must of been dialed high. No actual way of reading without a O2 regulator.



Sent from my SM-G920V using Tapatalk

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I think most things hold true regardless of weither it's beer or wine yeast. I hope to get Chris White and other yeast experts on the radio show in the near furture.

zpeckler said:

A bit of a digression, but I'm wondering what pieces of equipment you guys use for oxygenation?

Currently I'm using your classic aquarium pump attached to a 2micron stone, plus a lot of agitation with my lees stirrer. Controlled oxygenation with pure O2 is the last big step I have to take towards total control over all the variables in my meadmaking. What's stopped me form pulling the trigger is that if I'm going to shell out for an O2 system I want one where I can measure and control the flow rate; i.e. set the flow to a given L/min. After reading "Yeast" I'm doubly convinced that I don't want to spend the money for an oxygenation system unless it's one where I can add O2 at a rate that I can control. Unfortunately, the O2 systems available at the big online retailers (MoreBeer, Northern Brewer, Midwest Supplies, etc) include regulators without measurable flow rates.

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Yes it's true no flow rate monitoring with the more beer gear. That is the cheapest system. WIth you already owning the stone you only need to spend $35 to get the fitting. Don't buy a medical O2 bottle unless you can get a Dr's script. They won't fill it without one. I use a .5 stone. Lets look around and see if we can find a youtube, or similar showing what the regulated flow looks like. I think even if you don't know for sure, only being able to get the 8ppm with an aquarium pump (which is only 2/3 the way there) it can't hurt to use the pure O2. I'm going to hunt for some help.

So here's my thoughts.

Yeast can actually make their own O2 = (respiration). This is how they feed themselves which give us the alcohol. Please see this ,,,, https://www.morebeer.com/articles/oxygen_in_fermentation

So the O2 we give them at pitch and possibly there after, in leu of this and other reads would indicate that the O2 is used/stored to maintain the cell membrane. Particularly, at the end of ferment when things get difficult. Building and maintaining armour if you will to combat the toxicity.

Lastly here is what the measured in ppm with different applications in 20L,,,, Shaken for 5 minutes,,,,2.71 ppm,,,30 seconds pure O2,,,,5.12, 60 sec O2,,,9.20, and 120 seconds gave 14.08 ppm

I have always wondered if the biomass is established based on volume and conditions. Lets face it, at some point the yeast decide it's time to get to work, yes? I'm working backwards here so hear me out. Yeast replicate (bud) for 12-15 times before there are spent. The spawn every 3-4 hours. I think perhaps this is how the biomass is determined. If they can determine work load maybe they can do the math and fiqure how many yeast they need and how many spawns would generate enough mass to get to the end with a certain desired population.

If you look at elk heard populations we know that a certain plot of land can support X amount of elk in good fashion. This is caller caring capacity. Once the caring capacity begins to wain the elk naturally migrate to new land to allow regeneration the the tired plot of land. I wonder if yeast can sense a certain caring capacity of a volume of must? This is my next hunt. To find how the biomass is determined.
In the "yeast book" they show several graphs that prove the proper O2 equates to a faster ferment, higher attenuation. The comparisons that are graphed are 2.7, 5.12, 9.2 and 14.08. You can see the higher O2 does everything better.

Duplicate sorry, duplicate sorry, duplicate sorry,