Wort oxygen content

[mike_hausenfluck]

I'm about to begin AG brewing.  How important is it that I use some wort aeration device to make sure that I have sufficient oxygen in my fermenter prior to pitching my yeast?  
Up to now, I've just poured a concentrated wort from my brew kettle into my fermenter containing water.  There has never been a problem with my yeast activity.  I'm worried that wort that's being cooled and pumped directly from a larger brew kettle might not have sufficient dissolved oxygen for yeast.  
The bottom line is, is it worth the extra money for aeration equipment?  Any answers?

[bonjour]

It depends.

Aeration of wort is important to the health of the yeast you pitch.   Obviously it is always better to aerate.  

It depends of how much you are going to stress the yeast.  If you are brewing a BIG beer it is more important.  If you don't pitch a well aerated started it's more important.

The device I use is my immersion chiller.  That needs an explanation, but it does point out that a fancy device, while nice, is not always needed.

What I do is AFTER ther wort is COOLED (prevent HSA) move the coils of the chiller rapidly up and down thru the wort.  Because there are many coils, there is much splashing while I do this.  Low Tech, yea, but it works.  I frequently brew 11-12% beers this way with good results.

Fred

[Shakey_Dog]

That is a good idea Fred.

I use an attachment that goes on the end of the transfer tubing that  sprays the cooled wort to aerates turing transfer from the boil pot to carboy.  Then some shaking and never had a problem.

I also brew big beers.  Lite for me is 7%

I think I will also start shaking the the chiller also.

Don

[Frank]

I've made rather large brews with shaking the fermentor as my only means of aeration. Generally, I shake it for thirty seconds. Rest. Then shake it thirty more. It helps to do this before all the wort is transfered since it'll be lighter then. This definitely gets me faster starts than when I used to just dump it in, splashing as much as possible.

[Yeasty]

I always just splashed like the devil, then shook the carboy. Also shook my starter really well before pitching.
But this last brew, a 1.080 IPA, I took the end cap off my auto syphon, and aggressively pumped the wort into the carboy with it. I did this for about half the total volume, and ended up with about 2.5" of foam at the top when done. I also had some healthy yeast started, but there was definitely major blowoff happening by nightfall. Wow. I think I'll do this until I think of something better. Hope it doesn't break my rack!
Taylor

[littlebrew]

I recently made a 10 gallon batch of Strawberry Wheat aereated with a LARGE aquarium pump.  The air was filtered through the (contained) aquarium filter, and through a homemade sanitizing apparatus.

I have NEVER had such a vigorous fermentation...2 hours later I had to place a blow off tube in  vs my standard "bubbler".

I will never shake another carboy. (I went and got a back-up aerator...just in case.