[astrivian]

I am curious as to what strategies you all use for oxygenating the wort. What i usually do is pour the wort back and forth between two buckets about 5 times. Do you think that is sufficient?

Also, there is something i never quite understood about this: Do you oxygenate when the wort is hot or cool? I have been doing it when the wort is cool just before i pitch but i think i have read some people say they oxygenate hot.

[bonjour]

I use an immersion chiller, when my wort is below 90F I pull the chiller up and down thru the wort increasing the chill rate (via agitation) and aerating the wort at the same time.  Works great, even for really big beers.

Fred

[tygo]

I usually pick the carboy up and shake the hell out of it for about a minute.  Works well but a little hard on the back and arms.

For really big beers or if I'm fermenting in a bucket I've been using a diffusion stone to blow pure O2 through the wort for 30-60 seconds.

I think pouring back and forth a few times should be fine for most beers.  But wait until the wort is cooled (below ~80-85F) or there could potentially be off-flavors in your beer as it ages.

[bluesman]

I use a mix-stir rod with an electric drill. It incorporates alot of air in a short amount of time. I find that this method works well for me.

[richardt]

Fred, do you wait until the temp gets below 80-85F to do that in order to avoid hot side aeration (HSA?)

Astrivian, here's my method:  I just attach a sanitized fine nylon mesh bag to the end of my output hose to filter out any hop particles and then put it inside a SS bullion china cap strainer and large nylon funnel (w/ screen) and have it drain into the better bottle or SS corny keg for fermentation.  All that screen-induced agitation seems to aerate it fine.  And it is a lot less effort physically.  I also do not use O2 bottles, aquarium pumps, or aeration stones.  I have read conflicting accounts as to whether aerating (with air) versus oxygenating (with O2) is better.  YMMV.

[tubercle]

Wait until its cool. The cooler the better. Liquid has a saturation point for dissolved gasses and the lower the temp the more gas (oxygen in this case) it can hold. That is one reason your are having to oxygenate it the first place. The boiling of the wort drives most of the free oxygen out and now you are having to replace it for the yeast to use.


 That's science as Tubercle understands it.

[kramerog]

I place a fermentation stone in the kettle towards the end of cooling to aerate and to increase both heat transfer and uniformity of temperature.  I may pitch yeast in the kettle if I'm using the same yeast for the entire 10 gallons and continue aeration to mix everything up.  During the transfer into carboys, I orient the hose so the wort fans out on the side of the carboy to maximize air-wort contact.  The fanning of the wort is a winemaking technique I picked up.  Finally, I might rock the carboys a little. 

[bonjour]

Fred, do you wait until the temp gets below 80-85F to do that in order to avoid hot side aeration (HSA?)

Astrivian, here's my method:  I just attach a sanitized fine nylon mesh bag to the end of my output hose to filter out any hop particles and then put it inside a SS bullion china cap strainer and large nylon funnel (w/ screen) and have it drain into the better bottle or SS corny keg for fermentation.  All that screen-induced agitation seems to aerate it fine.  And it is a lot less effort physically.  I also do not use O2 bottles, aquarium pumps, or aeration stones.  I have read conflicting accounts as to whether aerating (with air) versus oxygenating (with O2) is better.  YMMV.

Yes,  that is the reason for waiting

Fred

[Hokerer]

I had to give up on my aeration stone because I couldn't use it as long as I wanted before the foam came out the top. Instead, I just connect the aquarium pump to a racking cane and blow bigger bubbles for a longer time to accomplish the same thing.  No foam issues.

[astrivian]

Okay it sounds like i am on the right track at least. Most of my OGs are 1.100 or higher but i realized i have been skimping on the oxygenation, which is probably why my attenuation isn't as high as it could be (I just read the "How to brew a BIG beer" article, it is great).

Maybe i will increase the number of times i pour the wort back and forth. Gives a good workout too

Also, i used to be into reef keeping and i remember that cooler water will hold more CO2, but i didn't know it was true with all gasses. That explains it well.

I have never tried the air pump, but i have several. Another reef keeping note: When i used to raise phytoplankton we used hard airline tubing attached to flexible tubing to oxygenate the jars. Airstones can harbor bacteria and are often only fully sanitized with a pressure cooker. The hard airline tubing makes relatively small bubbles and is easiest to clean; plus you can get a bigger pump and a gang valve and split one tube into four or eight. You could just use flex tubing but it is hard to manage.

[bonjour]

(I just read the "How to brew a BIG beer" article, it is great).

thanks

Also, i used to be into reef keeping and i remember that cooler water will hold more CO2, but i didn't know it was true with all gasses. That explains it well.

hold for all gasses at "normal" temps

[richardt]

... i remember that cooler water will hold more CO2, but i didn't know it was true with all gasses. That explains it well.

Cooler liquid will hold more gas (CO2 or O2 or NO2) than warmer liquid.  Another way of saying it is a warmer liqid holds less gas than a cold liquid.  Keep this in mind when pouring a highly carbonated colder liquid into a warmer glass, bottle, or vessel (=foaming).  Of course, nucleation sites (e.g., scratches, pits, or sugar granules) play a role with the speed at which this occurs.

[sienabrewer]

I use a mix-stir rod with an electric drill. It incorporates alot of air in a short amount of time. I find that this method works well for me.

+1 that is my method too.  Just be careful not to let the rod hit the bottom of the bucket as you are letting it rip.  It will scratch your bucket, and I know this from first hand experience.

[zombywoof]

I typically pitch between 75 and 80 degrees. I use a stone with those red oxy bottles you get from HD. I have read many different opinions on how long to oxygenate, some based on temp, some based on OG, etc.. Most of my beers tend toward the higher OG range. I have been increasing the time of late because I don't seem to get as far along in fermentation as I think I should. Is there a "Too Much" when using a stone? Is there a "Rule of Thumb"?
Thanks

[bonjour]

IMHO 75-80 F is too warm to pitch for almost all beers
ROT i follow is to pitch low and allow the wort to warm up to fermentation temp.

If I pitched my big beers at that temp they would be undrinkable.

Fred