Do you Aerate your Wort ?

[simmons]

I have read in many books that it is good to Aerate your wort while it chills before you pitch your yeast. Does anyone have any experience with this. I'm wondering if there are any negative affects from this as well.

 

[TheMethod]

Yes, it is good to aerate your wort. There is only one time that you want to do this in the entire process and that is after you have cooled the wort but before you have added the yeast.

The yeast need the oxygen in order to do their stuff. Although you may be able to get by without aerating, it really does help.

Aerating while the wort is still hot will give you hot side aeration (what an apt term). This will give your beer an off flavor.

Adding oxygen after the yeast have started will also oxidize the wort in a bad way. So when you're transferring from primary to secondary or to the bottling bucket you don't want it to splash that much. This is also why bottle caps can have the little oxygen absorbing thing on the inside. It helps prevent oxidization of your beer.

In short: aeration after cooling but before fermenting is good. Any other time is bad.

 

[tasq]

Yes most people aerate. Boiling removes most of the oxygen from your wort. The yeast need oxygen to work. There are no negative effects at this stage in the game. After fermentation is when you want to be worried about introducing oxygen into your beer.

Hope this helps!

 

[oceanselv]

Be careful when aerating your wort when it is hot. Hot side aeration will increase melanoidins in your wort. These compounds will increase the staling in your beer. The best time to aerate the wort is when you have cooled to pitching temperature. At cooler temps the oxygen is not as reactive and does not oxidize the wort as much as at higher temps. There are a few ways to aerate as well. Many people use an aeration stone and pure oxygen; others use an aquarium pump and an aeration stone while others let their cooled wort to free fall into the fermenter and others use a stir plate with a stir bar for their yeast starter. I prefer to use the yeast starter method as this helps get the fermentation started quicker and minimizes any problems of contamination or off flavors.

 

[psuchunk03]

i aerate with a sanitized whisk after i pour the chilled wort into my bucket, but before pitching the yeast. whisk until you're arm is going to fall off! :rockin:

 

[simmons]

Thanks for all the replies this helps a ton.

 

[SumnerH]

Be careful when aerating your wort when it is hot. Hot side aeration will increase melanoidins in your wort.

Hot side aeration is nearly impossible to introduce at the home-brewing scale. I'd say it's a complete myth, but in a large commercial setup where there's compressed air/oxygen involved it might be possible to actually see some effects from it.

It requires vast amounts of aeration, though; Sierra Nevada and plenty of other breweries have their mash runoff cascading several feet into their kettle like a waterfall, with no ill effects. Heck, here's Allagash doing a hot wort transfer:
http://www.youtube.com/watch?v=wD_49kfVJeE#t=5m19s

Just sloshing things around at home isn't going to accomplish it.

 

[jakecpunut]

What about straining? I've been pouring my cooled wort into the fermenter through a strainer and that seems to aerate it pretty well... any thoughts on that?

 

[rexbanner]

Hot side aeration is nearly impossible to introduce at the home-brewing scale. I'd say it's a complete myth, but in a large commercial setup where there's compressed air/oxygen involved it might be possible to actually see some effects from it.

It requires vast amounts of aeration, though; Sierra Nevada and plenty of other breweries have their mash runoff cascading several feet into their kettle like a waterfall, with no ill effects. Heck, here's Allagash doing a hot wort transfer:
http://www.youtube.com/watch?v=wD_49kfVJeE#t=5m19s

Just sloshing things around at home isn't going to accomplish it.

I've also heard that post-fermentation aeration isn't really a cause for concern, either. I could be misinformed though.

I've always aerated just by vigorously pouring my wort from the kettle into the bucket, and then shaking it a lot. I've never had to repitch, and I've never had fermentation take longer than 24 hours to start.

 

[HeavyBrew]

What about straining? I've been pouring my cooled wort into the fermenter through a strainer and that seems to aerate it pretty well... any thoughts on that?

+1.. I use one of those funnel strainers and I think that does a great job aerating the wort.

 

[SumnerH]

I've also heard that post-fermentation aeration isn't really a cause for concern, either. I could be misinformed though.

Post-fermentation aeration risks oxidation. It's not going to kill things immediately, but it'll decrease the storage life of your beer (possibly dramatically, depending on other factors like whether you're bottle conditioning and the like). A minor splash here and there isn't a huge deal, but it's definitely worth keeping things as still as possible during post-fermentation transfers.

 

[psuchunk03]

What about straining? I've been pouring my cooled wort into the fermenter through a strainer and that seems to aerate it pretty well... any thoughts on that?

SO I NEED TO RUN INTO YOU OVER HERE, JAKE!!!! lol we miss you over at MrBeerFans... guess you've moved on to bigger an better things

yeah, the strainer will aerate plenty... any other method you use, as long it's not pure O2 supersaturation, won't hurt either.

 

[ReverseApacheMaster]

What about straining? I've been pouring my cooled wort into the fermenter through a strainer and that seems to aerate it pretty well... any thoughts on that?

It aerates the wort a little, but it doesn't do a lot.

Yeast need oxygen to reproduce. Boiling removes a lot of oxygen from the wort, so without aeration your yeasts have to struggle with the available oxygen, which can result in slow or stuck fermentations, especially if you underpitch and/or the wort has a high SG. The more aeration you can do, the better.

 

[marc06]

Hot side aeration will increase melanoidins in your wort

Riddle me this? How does this happen, with references?

Melanoidans will act as antioxidants after the boil, but melanoidans are mostly formed during the boil.

 

[ScrewyBrewer]

I use a sanitized spoon to whip up the wort both prior to pitching and after pitching my yeast.

Photo of my fermenter after pitching some dry yeast and aerating it with a spoon.

Screwy Brewer

 

[ReverseApacheMaster]

Post-fermentation aeration risks oxidation. It's not going to kill things immediately, but it'll decrease the storage life of your beer (possibly dramatically, depending on other factors like whether you're bottle conditioning and the like). A minor splash here and there isn't a huge deal, but it's definitely worth keeping things as still as possible during post-fermentation transfers.

There are several non-saccharomyces strains of yeasts that require oxygen in the solution to grow. These yeasts come in contact with your beer when you rack and bottle, but generally they cannot multiply because you beer is full of CO2 and no oxygen. When you get aeration post-fermentation, you increase contact with these yeasts and give them the necessary oxygen to multiply and consume sugars in the beer. These yeasts are responsible for the cardboard taste in beers that are associated with oxygenation.

If I remember correctly, they are also the same yeast strains responsible for yeast infections. Mmmmmmmmmmmmmmm!

 

[oceanselv]

Hot side aeration is nearly impossible to introduce at the home-brewing scale.
Just sloshing things around at home isn't going to accomplish it.

Riddle me this? How does this happen, with references?

Here is a synopsis of an article by George Fix. http://www.brew-dudes.com/hot-side-aeration/124. And from Chapter 6 of How to Brew by John Palmer: "Chapter 6 - Yeast

6.9.3 Aeration is Good, Oxidation is Bad

The yeast is the most significant factor in determining the quality of a fermentation. Oxygen can be the most significant factor in determining the quality of the yeast. Oxygen is both your friend and your enemy. It is important to understand when which is which.

You should not aerate when the wort is hot, or even warm. Aeration of hot wort will cause the oxygen to chemically bind to various wort compounds. Over time, these compounds will break down, freeing atomic oxygen back into the beer where it can oxidize the alcohols and hop compounds producing off-flavors and aromas like wet cardboard or sherry-like flavors. The generally accepted temperature cutoff for preventing hot wort oxidation is 80°F.

Oxidation of your wort can happen in several ways. The first is by splashing or aerating the wort while it is hot. Other beginning-brewing books advocate pouring the hot wort after the boil into cold water in the fermenter to cool it and add oxygen for the yeast. Unfortunately the wort may still be hot enough to oxidize when it picks up oxygen from the splashing. Pouring it down the side of the bucket to minimize splashing doesn't really help either since this increases the surface area of the wort exposed to the air. Thus it is important to cool the wort rapidly to below 80°F to prevent oxidation, and then aerate it to provide the dissolved oxygen that the yeast need. Cooling rapidly between 90 and 140°F is important because this temperature region is ideal for bacterial growth to establish itself in the wort."
Melanoidans will act as antioxidants after the boil, but melanoidans are mostly formed during the boil."

 

[whatsleftofyou]

Here's some good info for you:
http://www.byo.com/stories/wizard/article/section/121-mr-wizard/931-is-it-possible-to-aerate-your-yeast-too-much

 

[marc06]

Thank you, however I still disagree that HSA will affect melanoidan formation. In the synopsis article of George Fix, it doesn't say anything about melanoidan formation, only oxidation. That melanoidan oxidation is what is going to cause staling of beer.

 

[jakecpunut]

SO I NEED TO RUN INTO YOU OVER HERE, JAKE!!!! lol we miss you over at MrBeerFans... guess you've moved on to bigger an better things

yeah, the strainer will aerate plenty... any other method you use, as long it's not pure O2 supersaturation, won't hurt either.

ha, yeah i only did 2 Mr Beer batches... i'm gathering the equipment to do AG and should be there by this weekend! FUN STUFF

btw, I still lurk around MrBeerFans!

 

[VanHolton]

I pour my cooled wort back and forth between two sanitized buckets. It works really well for me. I used to shake, but in the end, this is much easier. The only downside is that it's really frothy if I need to funnel to a carboy. If I'm fermenting in the bucket, it's really nice.

 

[Bensiff]

I wouldn't worry about HSA unless you are running a can of O2 into hot wort. I use a 60 second shot of O2. I don't have to worry about introducing nasties from the air and it provides consistency to my process not to mention I have never had an issue with stuck ferment or high FG with it.

 

[Meatball358]

Ive been following this guys technique for my first 2 batches. I tend to go a bit gentler than this guy did but I was wonderin if anyone has any thoughts about this one. anything seem wrong with this method??

 

[whatsleftofyou]

Ive been following this guys technique for my first 2 batches. I tend to go a bit gentler than this guy did but I was wonderin if anyone has any thoughts about this one. anything seem wrong with this method??

My buddy does something similar and it's fine. Keep in mind that regardless of how you insert air - whether via mixing/splashing, shaking, or with a stone - you're getting a max of 8ppm O2.

 

[Meatball358]

My buddy does something similar and it's fine. Keep in mind that regardless of how you insert air - whether via mixing/splashing, shaking, or with a stone - you're getting a max of 8ppm O2.

Ok...well bearing in mind that Im getting a max of 8ppm...what is the ideal amount of O2 during aeration

 

[whatsleftofyou]

I've seen varying numbers from 8-15ppm. I'm at work right now so I unfortunately don't have George Fix's book to reference. Really the only way to get >8ppm is to shoot it with pure O2 and that is really just estimating since there's no way of measuring it at a homebrew level.

 

[simmons]

I think the aquarium air pump and the air stone has worked so far. Plus I'm usually 3 or 4 beers into it when it's time to aerate the wort so I'll stay away from power tools.

 

[jakecpunut]

 

[permo]

I strain my wort, above the fermenter through a fine wire mesh strainer, this thoroughly oxygenates the wort and makes it all nice and "frothy" in the fermenter. I am assuming I am at 8 PPM with this method. Also, hop sediment and trub is caught in the screen.

 

[buenaventura]

Aerating while the wort is still hot will give you hot side aeration (what an apt term). This will give your beer an off flavor.

Well, sh*t.

I didn't know that . . . thanks for the heads up.

Here's hoping the APA I have bottle conditioning doesn't taste like crap.