Aerating the wort.

[Moezart]

Hello.
I am about to pitch 2 packs of US 04 in a 5 gallon batch. I usually stir the hell out of my wort for aeration before I sprinkle the yeast... But I am thinking now should aeration be done before pitching yeast, or should I pitch then stir the hell of it?
Using fermenter bucket no carboy
. Thanks

 

[brandonlovesbeer]

I honestly don’t think it matters.
I’ve aerated pre and post pitch with no detrimental effects either way.

Honestly though instead of stirring vigorously or shaking a carboy,
Transfer from the boil kettle to fermentation vessel vigorously.

I usually siphon out of boil kettle and allow the wört to drop from a height instead of just dropping the hose to the bottom of the ferm vessel and letting it fill slowly and calmly.

 

[Moezart]

I honestly don’t think it matters.
I’ve aerated pre and post pitch with no detrimental effects either way.

Honestly though instead of stirring vigorously or shaking a carboy,
Transfer from the boil kettle to fermentation vessel vigorously.

I usually siphon out of boil kettle and allow the wört to drop from a height instead of just dropping the hose to the bottom of the ferm vessel and letting it fill slowly and calmly.

Thanks. But my boil kettle has no spigot... So I have to kind of wrestle the thing.. Lol... Thanks

 

[BobBailey]

Dry yeasts require little or no aeration. If properly handled and stored, they have everything they need to kick off a healthy fermentation when pitched at a reasonable rate and within their published temperature range.

Also, Fermentis no longer recommends rehydration with their ale yeasts. They say that the viability lost by not rehydrating is insignificant.

 

[brandonlovesbeer]

Thanks. But my boil kettle has no spigot... So I have to kind of wrestle the thing.. Lol... Thanks

Like I said in my original post,
I just use a siphon to transfer it from the boil kettle to the fermentation vessel.

And I just hold the hose high and make sure it splashed a lot during the transport.

Let it do that for the full 5 gallons and
that is more that enough aeration.

 

[couchsending]

No aeration needed for dry yeast.

 

[Dland]

Mostly I use 05 and 34/70, I was aerating with O2 and a wand religiously. Decided to try it without aeration and it works out just fine. Nice to eliminate a step whenever possible. No worries about contamination from stone, no starter, just pitch when wort is close to desired temperature, it works every time. It is good to aerate when re pitching yeast however.

One question I have; Is aeration more beneficial with very high gravity worts?

 

[mongoose33]

I'm wondering where this "no aeration needed for dry yeast" thing is coming from. Can anyone point me to some links from authoritative sources that say this? It doesn't make sense to me.

My understanding is this: yeast need oxygen to build cell walls. And while, yes, supposedly dry yeast is in some sense "oxygenated" enough to give the dry yeast a good start, I'm having a hard time wrapping my head around the idea that's anywhere near enough to support the repeated budding and new cells the yeast will produce. White and Zainascheff, in their book 'Yeast,' make no mention I can find that dry yeast needs no aeration.

Dry yeast is supposed to have oxygen somehow incorporated, but I'm having a hard time believing whatever amount that is would be enough to support the later generations. Perhaps I'm just uninformed about this, so I hope someone can expand on this.

 

[couchsending]

It’s all over the web. You can find info on this forum, AHA forum, probrewer, the dry yeast manufacturers website etc.

Dry yeast is packaged with enough sterols for replication. Yeast needs O2 to produce sterols in order to replicate.

Rehydration is all you need.

I aerate every liquid pitch every time with a wand and O2... never with dry yeast.

 

[mongoose33]

It’s all over the web. You can find info on this forum, AHA forum, probrewer, the dry yeast manufacturers website etc.

Dry yeast is packaged with enough sterols for replication. Yeast needs O2 to produce sterols in order to replicate.

Rehydration is all you need.

I aerate every liquid pitch every time with a wand and O2... never with dry yeast.

I'm just wondering what authoritative sources you found convincing in this. I'm just surprised because despite my infatuation with brewing, I've never run across a single source that said this--other than in this thread.

 

[specharka]

I'm just wondering what authoritative sources you found convincing in this. I'm just surprised because despite my infatuation with brewing, I've never run across a single source that said this--other than in this thread.

https://fermentis.com/tips-n-tricks/questions-and-answers/

It’s there, half way down the page.

 

[mongoose33]

https://fermentis.com/tips-n-tricks/questions-and-answers/

It’s there, half way down the page.

Thank you. I'm attending the BYO boot camp in Asheville in March, and one of the workshops I'm doing is the Yeast workshop put on by Chris White (White Labs). I'm going to ask him about this. It just went on my list of questions for the boot camp.

 

[Silver_Is_Money]

As has already been stated above, there is no need to aerate the wort for dry yeast. Lallemand/Danstar makes this explicit, and (if they are to be trusted) those who claim to have inquired of this issue with Fermentis have been told the same.

The reason for this is that normally yeast need oxygen so they can synthesize some compounds they require before they can begin to turn sugar into alcohol, but these compounds are already present in fully adequate quantities within a pack of dry yeast. This from Lallemand.

Edit: I see from the link provided by the poster above me that Fermentis has also explicitly confirmed this.

 

[ncbrewer]

The Lallemand website previously stated that there is no need to aerate wort when pitching with dry yeast. But I can no longer find that information on the website. I contacted the company to find out whether the recommendation has changed or if it was an oversight. I'll post what I find.

 

[Silver_Is_Money]

The Lallemand website previously stated that there is no need to aerate wort when pitching with dry yeast. But I can no longer find that information on the website. I contacted the company to find out whether the recommendation has changed or if it was an oversight. I'll post what I find.

I just checked, and this is still explicitly stated for each of their brewers yeasts on their respective "Technical Data" sheets. Aeration is not necessary.

 

[CodeSection]

To sum up my understanding, when using dry yeast US-05 or US-4, rehydration is not needed; yeast nutrient like Fermaid is not needed; and aeration is not needed....

 

[Silver_Is_Money]

To sum up my understanding, when using dry yeast US-05 or US-4, rehydration is not needed; yeast nutrient like Fermaid is not needed; and aeration is not needed....

I still rehydrate. And I'm going to start adding Fermaid and a few drops of a weak 'USP grade' zinc sulfate solution as well.

 

[CodeSection]

I always rehydrated, used Fermaid and aerated when using the dry yeast ....But after reading the links and sites, along with these posts, I guess it is not needed...

 

[bleme]

I still rehydrate. And I'm going to start adding Fermaid and a few drops of a weak 'USP grade' zinc sulfate solution as well.

BeerAndBrewing.com posted a video last week and one of the points she made was that most yeast nutrient is just dead, dried yeast so instead she just tosses some yeast from an old cake in the boil. Makes sense....

 

[Dland]

BeerAndBrewing.com posted a video last week and one of the points she made was that most yeast nutrient is just dead, dried yeast so instead she just tosses some yeast from an old cake in the boil. Makes sense....

If this is the case, I guess it is a good use for those older expired dry yeast packets that some of us have sitting around.

 

[Silver_Is_Money]

Some good (and short) videos on dry yeast from a guy who quite recently visited one of the major dry yeast manufacturers.





Quick synopsis: No aeration needed, and it is actually detrimental. No rehydration needed, just pitch packs directly into wort. The worst thing you can do to yeast while rehydrating it is to agitate or stir it, and the poorest results were achieved for stirred yeast.

For the times they are a changing....

 

[Rev2010]

Quick synopsis: No aeration needed, and it is actually detrimental. No rehydration needed, just pitch packs directly into wort. The worst thing you can do to yeast while rehydrating it is to agitate or stir it, and the poorest results were achieved for stirred yeast.

Ya know, I've been following the directions exactly as provided by Lallemand and they say to rehydrate and to stir after 15 minutes to suspend the yeast completely. So wtf?? Who is right?? It's frustrating all the varying information. I have however also aerated with my O2 wand but guess I will stop doing that with dry yeast, which is actually better as it's one less thing to clean. Here's from Lallemand data sheet. I've bolded the stir part:

Rehydration of Nottingham is recommended for use, and will
reduce osmotic stress on the yeast when rehydrated and pitched
in liquid form. Rehydration guidelines are quite simple, and
present a much lower risk of contamination than a starter, which
is unnecessary with dried active yeast.
Sprinkle the yeast on the surface of 10 times its weight in clean,
sterilized water at 30-35°C (86-95F). Do not use wort, or distilled or
reverse osmosis water, as loss in viability will result. DO NOT STIR.
Leave undisturbed for 15 minutes, then stir to suspend yeast
completely, and leave it for 5 more minutes at 30-35°C. Then
adjust temperature to that of the wort and inoculate without
delay.

*EDIT - saw the vids. OK, so he states Fermentis is going to change their pitching instructions. Interesting to see that they are changing their instructions. Being it's coming from the company that provides some sollace. Wonder how Lallemand feels about this and if they've actually done studies to come up with their information.

Rev.

 

[Eric Tepe]

I have used Nottingham religiously an have pitched straight into the wort for years. In fact, I brewed a 1.068 Pumpkin ale Wednesday and pitched at 6pm. It was fermenting well at 8am the next morning.

 

[VirginiaHops1]

I usually shake my carboy like it stole something after dumping in my yeast, dry or liquid. Guess I can stop doing that for the dry.