Interesting Article on Wort Aeration

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I've heard that from various sources too. The Brew Strong show on aeration claimed that just filling the headspace of your carboy/bucket with O2 and shaking was just as effective as an oxygenation wand and stone.
 
When using a pump to pump room air into the fermentor its a slow process I wonder what would happen if they used a stone and an oxygen tank .
 
I wonder what the difference is between the rocking method and my approach, which is to use a paint stirrer attached to a drill.
 
DilvishTheDamned said:
I wonder what the difference is between the rocking method and my approach, which is to use a paint stirrer attached to a drill.
Click to expand...

None, I do this too and I believe it is extremely effective. The goal is to expose as much wort to as much air as possible. My drill mounted three pronged wine whip is quite good for this.
 
arturo7 said:
Am I the only one who splashes the wort into the fermenter? I usually get 2-3 inches of foam on top.
Click to expand...

I do a bit of that. I used to do a pretty long drop from the keggle into the fermenter, but now with my tiny valve, it seems to get a lot of foam just during the transfer, which is normal most transfers get about 50-60% saturation IIRC.
 
Wow. Well that article seals the deal for me. I will never be spending money on aeration equipment. Just shake away. You get better saturation and quicker results anyways.
 
I trashed that paper once before. The level of control and relevance is at a high school science level. First, water was used because of expense of wort? Seriously... you want to run a controlled experiment and document it and you can't spend a few bucks on DME?


The killer was:

In all experiments, the dissolved oxygen content of
the water immediately after it was delivered to the
ferment [sic] was significant.
Click to expand...

This says the water wasn't even fully devoid of O2 yet due to the short boil time. The other issue is that water and wort to do take on oxygen in the same way due to the different densities (as the article noted). My advice is to read the whitelabs paper and skip this one. The biggest deficiency was the absence of a pure O2 test. I'm being a little over dramatic, but it's a controversial topic and this experiment does little to seal the deal for me.

Anyway... who has better info? A team with a lab who tests all methods with wort (whitelabs) or a guy who already knows shaking is enough because he's too cheap to buy O2 and use actual wort in the experiment.
 
Bobby_M said:
I trashed that paper once before. The level of control and relevance is at a high school science level. First, water was used because of expense of wort? Seriously... you want to run a controlled experiment and document it and you can't spend a few bucks on DME?


The killer was:



This says the water wasn't even fully devoid of O2 yet due to the short boil time. The other issue is that water and wort to do take on oxygen in the same way due to the different densities (as the article noted). My advice is to read the whitelabs paper and skip this one. The biggest deficiency was the absence of a pure O2 test. I'm being a little over dramatic, but it's a controversial topic and this experiment does little to seal the deal for me.

Anyway... who has better info? A team with a lab who tests all methods with wort (whitelabs) or a guy who already knows shaking is enough because he's too cheap to buy O2 and use actual wort in the experiment.
Click to expand...

You seem a little bent out of shape over this, and I'm not sure why.

The article I posted states (in the abstract): "Conclusion: oxygen can be quickly dissolved into wort from the headspace of the fermentor with rocking/shaking." Now, either that conclusion is correct, or it is incorrect.

The authors state specifically they are only considering ambient air as a source of O2. In other words, not pure oxygen.

I didn't read the entire presentation at the link you posted, but it seems the relevant material is on page 30. On that page, results are presented that suggest 8ppm of dissolved oxygen can be achieved by "splashing & shaking" for 40 seconds. 8 ppm can also be achieved by using an aquarium pump with an airstone, in five minutes. Pure oxygen with an aeration stone is found to achieve 0-26 ppm in a minute.

So the study detailed at the link you provided draws the same conclusion as the paper you "trashed" as far as I can tell: oxygen can be quickly dissolved into wort from ambient air by "rocking/shaking" (aka "splashing & shaking"). The same levels of O2 can be achieved, and in a shorter time, by simply rocking/shaking as could be achieved by setting up a pump with aeration stone using ambient air. This is a significant finding for homebrewers who want to aerate their wort and are wondering whether it is worth the trouble of taking the "next step" to using a pump and stone. It seems like the answer is "yes, but only if you can provide pure oxygen."

I agree with you that the methods of the White Labs folks were clearly superior, but their findings support rather than refute the work I cited.
 
Am I missing something? I'm pretty new so that's probably the case, but is there some significant benefit to using O2 aerating pumps and stones and other such fancy equipment? I figured as long as the wort gets aerated enough that the yeast are able to do their job and effectively go from your planned OG to your planned FG, you've succeeded. :confused:
 
arturo7 said:
Am I the only one who splashes the wort into the fermenter? I usually get 2-3 inches of foam on top.
Click to expand...

this is the way i used to do it but with the pump I pump into the carboy and I just raise the silicone hose a few inches above the carboy neck and its aerates very well . I really don't know if its all that important since I pitch the proper amount of yeast so no real growth is going on in the carboy only exception is when I underpitch in some styles to achieve the right flavors like a Hefe

aeration.JPG


this method generally ended up having foam flow out the neck before it was full and it was wort not the Starsan
 
I really don't know if its all that important since I pitch the proper amount of yeast so no real growth is going on in the carboy
Click to expand...

Unless you pitch a 5 gal. starter, you will have growth (i.e. racking onto the full primary trub from a prior batch). Further, if you really could pitch yeast with no growth, it will lead to problems in the finished beer (see Palmer).

As for splashing, I don't think it is fully adequate (i.e. can't get 8 ppm O2). But it is simple enough to do and you have to transfer the wort anyway. So I splash, then shake, then stir. But it seems from the material on this thread, that splashing the wort into the carboy, then shaking for a minute would be good enough.
 
pkeeler said:
Unless you pitch a 5 gal. starter, you will have growth (i.e. racking onto the full primary trub from a prior batch). Further, if you really could pitch yeast with no growth, it will lead to problems in the finished beer (see Palmer).

As for splashing, I don't think it is fully adequate (i.e. can't get 8 ppm O2). But it is simple enough to do and you have to transfer the wort anyway. So I splash, then shake, then stir. But it seems from the material on this thread, that splashing the wort into the carboy, then shaking for a minute would be good enough.
Click to expand...

With proper pitching no large scale cell growth is going on. Sure there will be some but not like when you pitch a smack pack into 1.060 wort.
 
I have been getting stuck fermentations and am starting to think it was my aeration. I did the shake method for 3 to 5 minutes after splashing wort into the fermentor. I am starting with aeration as my temperature is fine. I bought an aeration pump and will use it this weekend on my next brew to see if that is the issue. I am interested to see if I just wasted my money or not.

Regardless, I am going to be a little at ease using a pump then shaking a 6 gallon glass carboy. We shall see.

I do agree though that the article does not really come to any scientific conclusion if they are not using wort at all...as the first argument stated (can't remember the name of the poster) the wort will hold onto air at a different rate. I would trust White Labs on this one more than this article.
 
smmcdermott said:
I would trust White Labs on this one more than this article.
Click to expand...

Go back and read my post at the end of the previous page. "This article" and "White Labs" reach the same conclusion--that rocking/shaking generates at least as much dissolved O2 as an aeration stone with ambient air, and in a shorter time.

Using a stone with PURE oxygen will potentially generate more dissolved O2.
 
I don't doubt that the shaking method will provide about 8 ppm. But that's an instantaneous snapshot. Oxygen levels in wort should start to immediately drop not only due to yeast uptake but other oxidizing reactions that will occur. O2 levels in wort can drop to zero in a few hours, maybe faster. By using the single shake/frothy wort transfer process, you're asking your wort to take one big gulp of air before it goes to work.

The continually aerating for an hour after pitching will give a constant O2 supply while the yeast go through a generation or two of growth. For bigger beers, aerating every couple hours until visible fermentation has started would probably be better.

Even if you do decide to re-shake every hour or so, the amount of available O2 in that carboy will depend on how much head-space you have. The issues I see is that a) some yeast need more than 8 ppm, and b) some yeast can take up that O2 very fast.

I'm not knocking the shake method. I'm sure there's plenty of people who have fermented with the shake method but this article won't change how I aerate. I'd like to see a comparison of O2 levels in wort over time between the two methods.
 
springer said:
With proper pitching no large scale cell growth is going on. Sure there will be some but not like when you pitch a smack pack into 1.060 wort.
Click to expand...

Proper pitching is designed to necessitate 3-4 growth cycles or an 8-16 fold increase in yeast cells.
 
MikeSzwaya said:
I don't doubt that the shaking method will provide about 8 ppm. But that's an instantaneous snapshot. Oxygen levels in wort should start to immediately drop not only due to yeast uptake but other oxidizing reactions that will occur. O2 levels in wort can drop to zero in a few hours, maybe faster. By using the single shake/frothy wort transfer process, you're asking your wort to take one big gulp of air before it goes to work.

The continually aerating for an hour after pitching will give a constant O2 supply while the yeast go through a generation or two of growth. For bigger beers, aerating every couple hours until visible fermentation has started would probably be better.

Even if you do decide to re-shake every hour or so, the amount of available O2 in that carboy will depend on how much head-space you have. The issues I see is that a) some yeast need more than 8 ppm, and b) some yeast can take up that O2 very fast.

I'm not knocking the shake method. I'm sure there's plenty of people who have fermented with the shake method but this article won't change how I aerate. I'd like to see a comparison of O2 levels in wort over time between the two methods.
Click to expand...

Good post. I've wondered about this myself.
 
I just finished listening to the podcast on Basic Brewing Radio with they guy that did this experiment. For those of you that are too busy to read it is the Aug 7, 2008 episode, and the next one, Aug 14 goes on to clear up the experiment with a few explinations. Good listen, and he does state that he is going to try with other methods, pure O2, wine wip, etc. but I am not sure if that has been done.
 
so the white labs document states that "Pumping air through a stone is not efficient". i guess they mean that because it takes 4 minutes longer than the other methods? just seemed like an odd conclusion to me. i certainly wouldn't consider 40/60 seconds vs. 5 minutes significant.
 
android said:
so the white labs document states that "Pumping air through a stone is not efficient". i guess they mean that because it takes 4 minutes longer than the other methods? just seemed like an odd conclusion to me. i certainly wouldn't consider 40/60 seconds vs. 5 minutes significant.
Click to expand...

I take it as inefficient given the hardware and time to accomplish the result.
 
android said:
so the white labs document states that "Pumping air through a stone is not efficient". i guess they mean that because it takes 4 minutes longer than the other methods? just seemed like an odd conclusion to me. i certainly wouldn't consider 40/60 seconds vs. 5 minutes significant.
Click to expand...
I think they're saying spending money and increasing risk of contamination in order to take 5x-7.5x more time (not including sanitizing the stone/etc.) = not efficient. 'Efficient' is relative. But you're right, 5 minutes is nothing on the scale of how long a batch takes to brew (it's only ~1% of my brewday).
 
osagedr said:
You seem a little bent out of shape over this, and I'm not sure why.
...
I agree with you that the methods of the White Labs folks were clearly superior, but their findings support rather than refute the work I cited.
Click to expand...

I'm not bent out of shape. I'm just countering the idea that the methods in that experiment are conclusive as the author suggests and subsequent readers here agree with. I just noticed that we've been saying white labs but it's a wyeast presentation. I could swear I saw a pdf from white labs on the same topic but I can't find it now.
 
SpanishCastleAle said:
If there were no growth you wouldn't need to aerate in the first place.
Click to expand...

I said no large scale growth not no growth at all.

Depends on the yeast too

Nottingham British Ale yeast has been conditioned to survive rehydration. The yeast contains an
adequate reservoir of carbohydrates and unsaturated fatty acids to achieve active growth. It is
unnecessary to aerate wort.

There always will be O2 in the wort unless you are doing everything in a sealed environment or are fermenting in the boil pot
 
springer said:
I said no large scale growth not no growth at all.

Depends on the yeast too

Nottingham British Ale yeast has been conditioned to survive rehydration. The yeast contains an
adequate reservoir of carbohydrates and unsaturated fatty acids to achieve active growth. It is
unnecessary to aerate wort.

There always will be O2 in the wort unless you are doing everything in a sealed environment or are fermenting in the boil pot
Click to expand...
remilard addressed the 'how much growth' earlier itt. The rest of your post just reinforces the 'would not need to aerate in the first place' even more. There is a reason the dry yeast mfrs. give their yeast those reservoirs...so they can grow. We don't need to go back and forth on this, I just think me and a few others thought it necessary to correct the 'I pitch the correct amount so no large scale growth occurs' (paraphrased) statement because it's incorrect.
 
SpanishCastleAle said:
remilard addressed the 'how much growth' earlier itt. The rest of your post just reinforces the 'would not need to aerate in the first place' even more. There is a reason the dry yeast mfrs. give their yeast those reservoirs...so they can grow. We don't need to go back and forth on this, I just think me and a few others thought it necessary to correct the 'I pitch the correct amount so no large scale growth occurs' (paraphrased) statement because it's incorrect.
Click to expand...

again with proper pitching no large scale growth is needed

When 100 g active dried yeast is used to inoculate 100 litres of wort, a yeast density of 5–10 million
cells per millilitre is achieved.

optimum yeast count is 10 million per milliliter correct? so if you have between 5 and 10 the yeast only need to reproduce once not the 6 to 8 times as been said. I dont call one generation large scale reproduction
 

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