Ask A Pro: Do you aerate your wort?

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A former homebrewer, and now brewmaster and co-founder of Brewster Bros. Brewing Co., James Stirn stresses the importance of adding oxygen before fermentation. Get the why, when and how from James in our next Ask A Pro!

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Link to full article: https://spikebrewing.com/blogs/ask-a-pro/aerating-your-wort



Don't forget to check out our previous Ask A Pro if you're a new brewer and intimidated by water chemistry. Ethan Tsai, Quality Control Manager at Tivoli Brewing Company, shares the importance of water chemistry and advice on how you can purify your water.

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Link to full article: https://spikebrewing.com/blogs/ask-a-pro/water-chemistry
 
omg the lodos are gonna lose it, lol
Isn't LODO brewing all about keeping the dissolved oxygen level to a minimum during the boiling and cooling process? I thought even when LODO brewing, you still aerated prior to fermentation?
 
I pour (moderately vigorous) from kettle to big mouth bubbler which induces a big frothy head of foam. I don't use an O2 stone or similar product.

Same. I pour through a sanitized paint straining bag adding lots of aeration evidenced by the epic foam. I also make it heavenly by stirring the hell out of it for good measure after adding the yeast.
 
I've used my dissolved oxygen meter on numerous occasions. By the time I boil, chill and flow into the fermenter, the wort is always fully oxygen saturated. Blowing additional oxygen into the wort does nothing and you can not exceed the saturation point. Additional aeration is not needed unless, by some low oxygen processes, you can't reach saturation naturally. But if it makes you feel better or gives one a sense of calm, go for it. It wont hurt anything.
 
I've used my dissolved oxygen meter on numerous occasions. By the time I boil, chill and flow into the fermenter, the wort is always fully oxygen saturated. Blowing additional oxygen into the wort does nothing and you can not exceed the saturation point. Additional aeration is not needed unless, by some low oxygen processes, you can't reach saturation naturally. But if it makes you feel better or gives one a sense of calm, go for it. It wont hurt anything.

Thanks for that^^^^ I’ll put down my stone then. No O2 meter here, I am sick of buying the tanks though.
 
I simply shake my Vitality Starter to get a frothy head and pitch it. Plenty of oxygen in the high krausen.
 
The title says "aeration", the article talks about injecting oxygen...

That's two different things and attempting to discuss them as the same technique can lead to apples/oranges comparisons...
 
The title says "aeration", the article talks about injecting oxygen...

That's two different things and attempting to discuss them as the same technique can lead to apples/oranges comparisons...
Come now, my apples are objectively better than your oranges.

But anyway, everyone knows max aeration DO is 8ppm, and it's not that hard to achieve... On the homebrew level.
Oxygenation can easily achieve more ... Whether that's actually helpful? That's up for debate. At the professional level, obviously you want to decrease lag time, but homebrew ... Who cares if lag time is 6 hours vs 18 hours but the final beer quality is essentially the same?
 
Oxygen saturation level of a fluid varies with temperature and atmospheric pressure (density is also in play to a lesser degree). You can not over saturate. Once it's maxed out, it's done. Any further attempt to oxygenate simply bubbles away into the atmosphere.
 
Oxygen saturation level of a fluid varies with temperature and atmospheric pressure (density is also in play to a lesser degree). You can not over saturate. Once it's maxed out, it's done. Any further attempt to oxygenate simply bubbles away into the atmosphere.
https://en.wikipedia.org/wiki/Supersaturation

When mixing wort and air (21% oxygen), the DO reaches equilibrium.

When mixing wort and oxygen (~100% oxygen), the DO reaches also reaches an equilibrium, one with higher DO. Usually the oxygen flow is stopped before reaching equilibrium so as not to over-saturate, since it's presumed excessive oxygen is toxic to yeast.

It's the same situation when you carbonate a beer. The CO2 is supersaturated. It will off-gas, but not immediately.
 
I've used my dissolved oxygen meter on numerous occasions. By the time I boil, chill and flow into the fermenter, the wort is always fully oxygen saturated. Blowing additional oxygen into the wort does nothing and you can not exceed the saturation point. Additional aeration is not needed unless, by some low oxygen processes, you can't reach saturation naturally. But if it makes you feel better or gives one a sense of calm, go for it. It wont hurt anything.

I suspect this will come as a shock to people like Chris White. You know, the guy who has White Labs, the guy who with Zainesheff wrote the "Yeast" book.

I suggest anyone who takes the above as gospel read that book, especially the section on oxygenating wort, and optimal oxygen levels. See if your conclusion differs from that above.
 
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yeast don't use the o2 instantly, so explain to me how this is not oxidizing the wort.

Also, we Low Oxygen Brewers (LOB, aka "LODO") emphasize pitching viable, healthy, and preferably active yeast, so yes, they do start using the O2 immediately. We do this by vitality starters or other means, but we're typically not pitching dormant yeast and waiting for them to wake up. That's why most of us are pushing bubbles in 4-6 hours post-pitch.

Active, healthy yeast, combined with the fact that oxidation reactions are slow at fermentation temps (but very fast at mash temps), prevent oxidation of the wort we have worked so carefully to preserve.

So yes, we LOB folks are big proponents of oxygenating at pitching.
For those looking for numbers, optimal O2 for fermentation is 8-12 ppm, IIRC.
 
I have an in-line oxygen stone attached to my exchilerator. I go from 10 gallons of wort in my brew kettle at 212 degrees to fermenter at 68 degrees fully oxygenated in 9 minutes. Then pitch my starter and I have airlock activity in about three hours.
 
I believe that Is standard for dry yeasts. Something about how they are packaged.

I'm going to suggest caution with regard to generalizing behaviors and characteristics of dry yeast strains across the various yeast labs.

The generalization may be true at a specific point it time. However, dry yeast is a manufactured product. And changes in a manufacturing process is often a competitive (or comparative) advantage.
 
I'm going to suggest caution with regard to generalizing behaviors and characteristics of dry yeast strains across the various yeast labs.

The generalization may be true at a specific point it time. However, dry yeast is a manufactured product. And changes in a manufacturing process is often a competitive (or comparative) advantage.
Moreover, we yet need to see hard data on those claims that dry yeast does not need oxygen. Although the (non-rehydrated) pitched dry yeast has sterol reserves built in, the daughter cells still need it themselves, especially to be able to propagate. It's those new cells that do most of the fermentation.

In typical homebrewers processes, enough oxygen may already dissolve during transfer to the fermenter, so additional oxygen may not be needed. That doesn't mean some extra oxygen won't be beneficial, especially at higher gravities.

I have a strong feeling the dry yeast manufacturers want to make using their products as easy and straightforward as possible without additional barriers, such as re-hydration, and aeration right before or after pitching. Only do 1 (!) instead of 1-2-3.

One more thing, as soon as fermentation starts any unused dissolved oxygen is being driven by off quickly by the huge volumes of CO2 being produced.
 
Moreover, we yet need to see hard data on those claims that dry yeast does not need oxygen. Although the (non-rehydrated) pitched dry yeast has sterol reserves built in, the daughter cells still need it themselves, especially to be able to propagate. It's those new cells that do most of the fermentation.

In typical homebrewers processes, enough oxygen may already dissolve during transfer to the fermenter, so additional oxygen may not be needed. That doesn't mean some extra oxygen won't be beneficial, especially at higher gravities.

I have a strong feeling the dry yeast manufacturers want to make using their products as easy and straightforward as possible without additional barriers, such as re-hydration, and aeration right before or after pitching. Only do 1 (!) instead of 1-2-3.

One more thing, as soon as fermentation starts any unused dissolved oxygen is being driven by off quickly by the huge volumes of CO2 being produced.

I'm going to the BYO brewing boot camp in Asheville at the end of March; lots of full-day workshops, including one on Yeast that's done by Chris White, for which I'm registered.

I'm accumulating questions I want to ask him, and one is about the "dry yeast don't need oxygenation" thing. I'll report back.
 
I have a strong feeling the dry yeast manufacturers want to make using their products as easy and straightforward as possible without additional barriers, such as re-hydration, and aeration right before or after pitching. Only do 1 (!) instead of 1-2-3.

I share this suspicion. Also consider the simple (to the yeast manufacturers) answer to most sub optimal yeast handling problems is to just buy and pitch more yeast.
 
I see a Brulosophy opportunity here. A Lallemand dry yeast added to one fermenter that has been aerated, vs. the same for no aeration.

And the follow-up would substitute a Fermentis yeast.
 
I see a Brulosophy opportunity here. A Lallemand dry yeast added to one fermenter that has been aerated, vs. the same for no aeration.

And the follow-up would substitute a Fermentis yeast.
And the result would likely be just like most of their experiments: no one can tell anything apart.

Sometimes it seems like their experiments indicate you could brew a perfect beer on one hand and then toss some grain in a bucket, pee on it, strain it through a dirty sock, and the panels wouldn't be able to tell the difference.
 
I see a Brulosophy opportunity here. A Lallemand dry yeast added to one fermenter that has been aerated, vs. the same for no aeration.

And the follow-up would substitute a Fermentis yeast.

Unless they learn how to properly do the taste tests, this probably wouldn't tell you much. Their testing procedures are very questionable.
 
And the result would likely be just like most of their experiments: no one can tell anything apart.

Sometimes it seems like their experiments indicate you could brew a perfect beer on one hand and then toss some grain in a bucket, pee on it, strain it through a dirty sock, and the panels wouldn't be able to tell the difference.
Ok let me see if I have this recipe right,

step one, toss grain in bucket
step two, take a piss on it
step three, strain through a dirty sock

This sinks a little low, no? I may have done the same, so at least you and I have that going for us.
 
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