Wort Aeration & Yeast

[jblack138]

When aerating your wort, do you pitch your yeast before or after aeration? Does it matter? I've seen recipes that call for doing it both ways and didn't know if there was a preference or a convincing argument to doing it either way.

 

[BigFloyd]

Before.

Are you using dry or liquid yeast?

 

[jblack138]

I've brewed 2 beers & used dry yeast both times. First beer got Nottingham & the 2nd got Safale S-05 Have not rehydrated the yeast either time, but plan on trying it on my next beer.

 

[grevengrevs]

before hand. And I have not re-hydrated my dry yeast, just tossed it in and let it go. Haven't had a problem. *crossing fingers!*

 

[Gavin C]

I oxygenate before pitching the yeast with one of these for 1-2 minutes.

Re-hydrating the dry yeast is simple. Just go to the manufacturers website to get the specific instructions for any given strain. Follow those instructions and you will have a greater number of healthy yeast in your sweet-wort.

There is research showing 50% death of dry yeast by pitching it straight into the sweet wort. Many wil state that they have great success doing just that and Brolsopher has done an exbeeriment looking at that very subject.

http://brulosophy.com/2014/09/15/sprinkled-vs-rehydrated-dry-yeast-exbeeriment-results/

With some dry yeast the manufacturers state that for an OG below a certain level oxygenation is not required. It won't cause any harm by doing it though. I oxygenate every batch regardless

In addition I've begun using yeast nutrient in my last couple of batches.

 

[HB_in_Subic]

I pitch my yeast after I have aerated the wort. I also rehydrate the yeast before I pitch. I usually give it a spoonful of corn sugar to get them going. I get much quicker active ferments using the rehydrated yeast (slows down after 2-3 days).

I aerate by just pouring my wort into the fermenting bucket from my kettle spigot. I typically get 3-4 inches of foam on top.

 

[Singletrack]

I oxygenate first, then pitch. I use pure oxygen, and I think that could be harmful to the yeast during application. However, this is just a hunch, and I realize that isn't much use to you. I'm interested to know what the researchers say.

If aerating with air, I would have no problem pitching first.

 

[chawn]

I forgot to aerate using O2 prior to pitching last weekend. There was no noticeable difference using hydrated US-05.

 

[Gavin C]

I usually give it a spoonful of corn sugar to get them going.

This is not such a good idea and not recommended by the manufacturers.

The rehydration process is not to get the yeast going but to rouse them from their inactive dried state without subjecting their cell walls to undue stress. Sudden temperature changes and asmotic pressures can cause cell lysis.

If you want to introduce the yeast to sugars before pitching some manufacturers state the addition of small volumes of sweet wort at the correct temperature can be added. Again the objective is not to feed the yeast but to gently bring them closer to the temperature and osmotic gradient of the wort they are soon to be exposed to.

I'm a firm believer in reading the manual. When it comes to dry yeast the manufacturers have gone to great effort to deliver a great product. They also have clear instructions on their websites. I am not a microbiologist nor a brewing expert but my thinking is that the likes of Danstar have quite a few on the payroll. I'm guessing they are there for a reason. I follow their simple instructions to the letter. They have already done the work. Who am I to disregard their advice. My goal is as optimal a fermentation as possible. Correct yeast management is one component in achieving this.

 

[progmac]

When aerating your wort, do you pitch your yeast before or after aeration? Does it matter? I've seen recipes that call for doing it both ways and didn't know if there was a preference or a convincing argument to doing it either way.

It doesn't matter

 

[unionrdr]

I suppose it doesn't really matter if you pitch before or after. But I pour my chilled wort through a fine-mesh strainer to get gunk out & help aerate the wort. Then top off with very cold spring water to recipe volume. I think since the top off water is cold & not boiled, it too has more air dissolved in it compared to the boiled wort, where boiling drives dissolved air out. And adding rehydrated dry yeast within 10 degrees of wort temp gives a healthier pitch with less lag time. Especially if pitched at high krausen.

 

[jblack138]

I've pitched both yeasts before aeration on my 2 brews. On my next one I'll try aerating first then pitching rehydeated yeast. It seems that for as many "rules" there are for brewing, there are that many more that are personal preference. Nothing a little trial and error won't fix! Thanks for all the input from everyone!

 

[HB_in_Subic]

I suppose it doesn't really matter if you pitch before or after. But I pour my chilled wort through a fine-mesh strainer to get gunk out & help aerate the wort. Then top off with very cold spring water to recipe volume. I think since the top off water is cold & not boiled, it too has more air dissolved in it compared to the boiled wort, where boiling drives dissolved air out. And adding rehydrated dry yeast within 10 degrees of wort temp gives a healthier pitch with less lag time. Especially if pitched at high krausen.

You are right on this. I did this by mistake on my last brew. I usually use some DME or a little bit of cooled off wort after the yeast has rehydrated for a little bit. I have noticed that the last batch was just slightly less vigorous as the previous one with DME.

 

[Ike]

So, assuming I'm going to be sticking to average OG beers (ales) made from extract/specialty grain kits for the moment, but am making the change toward full-volume boils, do I need to consider aeration? Or is it not as critical until I start pushing the envelope toward higher gravities or more complex brews that require more finicky yeast strains?

Ike

 

[HB_in_Subic]

I have always aerated with my 5-6% ales. I just do it passively with a pour from my kettle spigot to fermenting bucket. I usually have a good 2-4 inches of foam on the top when done. The last batch, there was so much foam (up to the lid) that I had to cover the hole in the lid while I pounded it shut with the rubber mallet as the foam was shooting out with each hammer.

 

[RM-MN]

So, assuming I'm going to be sticking to average OG beers (ales) made from extract/specialty grain kits for the moment, but am making the change toward full-volume boils, do I need to consider aeration? Or is it not as critical until I start pushing the envelope toward higher gravities or more complex brews that require more finicky yeast strains?

Ike

Maybe.

It depends.

OK, time for the answer, but first the question, are you using dry yeast or liquid?

Lets make the assumption that for the best beer you need a certain amount of yeast cells to ferment it. For a 5 gallon batch, dry yeast packages should contain enough yeast cells and the proper nutrient for them so that if you rehydrate the yeast before pitching you will have enough yeast for a batch with an OG of up to about 1.060. For bigger beers you probably should use 2 packages.

If you use liquid yeast, the package will contain fewer cells and lack the necessary nutrient to make more cells but.....the yeast can use the components in your beer to make cells....if they have oxygen. If you can oxygenate the wort sufficiently, a single packet of liquid yeast will grow in the wort until there is enough cells to do the job without stress. If you don't want to or cannot aerate the wort enough for that, you make a starter to grow more yeast cells and then pitch that.

 

[Ike]

Lets make the assumption that for the best beer you need a certain amount of yeast cells to ferment it. For a 5 gallon batch, dry yeast packages should contain enough yeast cells and the proper nutrient for them so that if you rehydrate the yeast before pitching you will have enough yeast for a batch with an OG of up to about 1.060. For bigger beers you probably should use 2 packages.

If you use liquid yeast, the package will contain fewer cells and lack the necessary nutrient to make more cells but.....the yeast can use the components in your beer to make cells....if they have oxygen. If you can oxygenate the wort sufficiently, a single packet of liquid yeast will grow in the wort until there is enough cells to do the job without stress. If you don't want to or cannot aerate the wort enough for that, you make a starter to grow more yeast cells and then pitch that.

This is really good food for thought! I guess I'd assumed liquid yeasts to be "better," as in being bigger colonies that would be more productive mostly because they just SEEMED that way rather than basing that thought on any particular data. The big, scary test tube full of goo that needs refrigeration to stay "good" just seems to be more alive and ready to rock than a flimsy package of dried dust. I'm also surprised that the liquid yeasts would be nutrient-poorer than dried, given their transportation in what was described to me as "nutrient solution" by the LHBS.

Well, time to keep reading, and to stop poo-pooing dry yeast!

 

[unionrdr]

Dry yeast packets contain more cells, but liquid yeasts have more variety. I like to rehydrate dry yeasts to cut lag time & get a more vigorous ferment. This can also cut fermentation time by pitching it at within 10 degrees of current wort temp. This gives a healthier pitch that goes quicker in my experiences.

 

[kombat]

With some dry yeast the manufacturers state that for an OG below a certain level oxygenation is not required.

I read that too. I even espoused the idea here on these forums for a while. Then I actually tried it with a batch. I brewed a 1.045 Pale Ale and racked it to a bucket with an autosiphon. There was no splashing, and I didn't aerate it at all. I just rehydrated, pitched the yeast, and put the lid on.

Banana city. It was a dumper. Ever since then, I thoroughly aerate all my beers, including those where I'm pitching rehydrated dry yeast.

 

[Gavin C]

I read that too. I even espoused the idea here on these forums for a while. Then I actually tried it with a batch. I brewed a 1.045 Pale Ale and racked it to a bucket with an autosiphon. There was no splashing, and I didn't aerate it at all. I just rehydrated, pitched the yeast, and put the lid on.

Banana city. It was a dumper. Ever since then, I thoroughly aerate all my beers, including those where I'm pitching rehydrated dry yeast.

I oxygenate every batch regardless of the yeast I am using. Totally agree with you on this point.

 

[unionrdr]

+1000. I awerate every batch to make sure the lil yeasties get everything they need to be fruitful & multiply.