Aeration: For the love of pete...

hot side aeration bad...

cold wort aeration good...

you gotta aerate intentionally and with tools...

no, you don't, your normal sloshing from pot to fermentor will aerate everything well enough....

color me confused. could you all give us beginners a breif (or lengthy, what do i care?) primer on aeration?

i'm especially interested in knowing:
when to aerate?
when to not?
how can i achieve both WITHOUT PURCHASING ANYTHING ELSE?

i've got a garden variety "beginners brewing equipment set".

thanks in advance...

Well, I do only partial boils with extract and steeping grains or a mini-mash and here's what I do:

After boiling, I put my brew kettle into the sink that has cold water and ice in it. I cover the pot to keep nasties out. When the water starts getting warm, I put it into the other sink also prefilled with cold water and ice. When the pot is not warm to the touch, I check the temperature of the wort. If it's cool enough (less than 90 degrees), I strain it into my primary bucket. I add cool water to the 5 gallon mark and stir with my sanitized spoon. I then pitch my yeast and cover and airlock.

Here's why- I don't want to oxygenate the hot wort (hot side aeration). When it's cool, it needs all the oxygen it can get. Since I only do partial boils, the water I add from the tap adds plenty of oxygen. Others who do full boils (or all-grain) have to use other means to add oxygen, since their water has lost oxygen when it boiled. That's why they have the aquarium pumps, etc.

The short answer is that if you are doing partial boils with extract and then adding water (tap water or spring water), you can shake, stir, strain, etc and it'll be enough oxygenation.

No need to buy any more equipment, don't worry!

Lorena

I also do partial boils, mostly. I boil about 4 gallons and add one. To aerate, I chill the wort, as usual, then add it to the carboy and shake the **** out of it. Like, for 2-3 minutes. You should be sweaty when you're done. Unless you're really in shape, but since you're a homebrewer, that condition won't last. Anyway, shake it a lot. Especially if you're using the pitchable liquid yeast. I've used white labs and it needs good aeration (ie, 5-10 minutes of shaking the **** out of it, or lots of sweatiness). As for dry yeast, for some reason it doesn't seem to need much aeration. I just shake a little bit and pitch. Then it works fine. Basically, any other time than when it first goes into the primary fermenter, treat it like a newborn baby.
Happy shaking.

Monk

I've got another question to add to this thread:
How hot is too hot to aerate wort. I used my 50' immersion wort chiller for the first time the other week (it was also my first 10-gal batch - I do extract with steeping grains) and pretty much got my wort to about 90 deg before I wasn't making any more progress at chilling it down.

So at ~90 deg, I transferred to my conical using the spigot on my 10-gal polarware pot to transfer to a sanitized bucket (it was quite an impressive stream if I say so myself) and then pour into my conical. I figured I was getting some pretty decent aeration b/c transferring from the spigot to the bucket allowed the wort to really churn up a lot, then pouring into the conical from the bucket churned it up even more.

But my basic question is this: I know it's better to actually aerate chilled wort - 60 deg or close to your pitching temp - but at what temp range are you risking hot side aeration and those nasty cardboard oxidation flavors? 100+? 90+?

Focus

The ONLY time aeration is a good thing is for your chilled wort. Get it below 80F and you'll be fine.

Wort aeration puts O2 into the wort so the yeast can grow. More O2 = more yeast

Splashing/shaking ~ 6-8 ppm O2
Air stone & pump ~12-15 ppm O2
Oxygen tank & stone ~ 33 ppm O2

Splashing/shaking is fine.

Remember, too, that if you're doing a partial boil and "topping off" in the fermenter, the top-off water is full of O2 (unless you have boiled that water).

Once my wort is cooled, I strain it through an adjustable strainer, which adds a lot of O2, gets it all nice and foamy. When I add my top-off water, I'm not shy about splashing around, I'll dump it in from a couple feet up. When I stir the wort prior to taking the SG reading, I'm not shy about getting some air in there. I'm sure at some point I'll buy an air stone, but for partial boils doing things like that are fine.

I can certainly appreciate your confusion because as a beginner I've noticed a bit of a catch 22. That is, exposing your wort to O2 now is also exposing it to potential infection.

I just did my first full boil since I got a big pot and immersion chiller. I poured my cooled wort into my bucket from about 4' up through a large strainer. It foamed so much that I had to stop pouring for a minute or two. I would assume this is enough aeration but who knows. I had airlock activity within 8 hours but it only lasted 2 days. I am now a bit paranoid that I didn't get enough O2 into solution. I thought of rocking my bucket to slosh, but I would assume that only CO2 exists in the headspace. The only solution would be to purge the CO2 out, allow new air in, then re-aerate. I don't think that's a good idea either. I wish I bought a hydrometer.

Bobby

I do 3 gallon partials, cool with ice water and immersion coils then dump into primary when temperature is around 90 or so. Dump the remainding required water with cold spring water but monitor temperature as I'm pouring. I actually made the wort too cold once and had to warm it up before pitching. I rehydrate my least with cooled boiled water. Put a few drops of wort in it to see if it goes nuts. When all is go, pitch the yeast and then stir with a sanitized spoon, like a mad dog. Get frothing and splashing going. I do that a couple of times and then air lock it with a bubbler and park it. This methodology has produced the best bubbling activity yet. The shaking the primary bucket didn't work at all for me.

BYO Article said:

Hot-side aeration is a loose term referring to oxygen pickup in the “hot side” operations of brewing. These include mashing, lautering, wort boiling and hop separation at temperatures ranging from about 120–212° F. Over about the last 15 years, researchers have presented evidence that hot-side aeration — especially prior to wort boiling — decreases the shelf-life of beer by increasing the concentration of oxidized fatty acids. These compounds are carried forward into the beer and impart classic stale flavors such as the infamous “wet cardboard” type of oxidation.

Click to expand...

The article goes on to say that hot side aeration is probably not a big concern for the average homebrewer, but it's also not hard to avoid. So you might as well try and minimize splashing when dealing with hot wort.

As covered above, aeration of cooled wort prior to yeast pitching is required for a healthy fermentation. My solution is a $40 regulator/hose/stone setup on top of a small O2 bottle (the size of a propane torch bottle). I bubble oxygen through a stainless aquarium aeration stone in my wort for about 5 minutes before pitching the yeast. This way I avoid the contamination from airborne bacteria that's possible with the splashing method.

guys I've been using either two buckets or a bucket and pot and just pouring back and forth, I'm getting a lot of air mixing in. Foam is telling me so. Has to be more than shaking.

i used to pour between two buckets before i got the oxygen kit.
pouring caused way too much foam - i would end up with 3/4 bucket of foam i would have to wait to collapse before i could add it to the rest of the wort.
use the oxygen and stone for 2 minutes and get minimal foam and good fast ferments(i use yeast starters as well)

I figured with Holy Hell comming up I should probably start thinking about aeration so I went out and got myself a whisper 10 air pump, some tube and some disposable air stones. Whole set up was about $15. I'll let ya know how it works. From what I read it should take 20 - 30 minutes to get enuff into the wort.

And yes I'm still looking for a filter for the air line. If worse comes to worse I guess I'll have to order one from NB. (I'm starting to be come disenchanted with my LHBS)

I also do partial boils, top off to 5 gals. in primary bucket, then pour into another sanitized bucket from about 2 feet high and then back again to primary. Plenty of aeration and nothing to buy, always a good fermentation.