Marty Tippin (martyt@pobox.com)
Original: November 15, 1996
Last Update: April 15, 1998
A recent posting to the Homebrew Digest asked about whether anyone had designed and used an inline wort aeration system like the big boys use - the idea is that this would be a gadget that would go between a counterflow wort chiller and the fermenter, and would inject air (or pure oxygen) into the wort as it flows to the fermenter, thus saving you from having to aerate later. I suppose this gadget could be used in most any system - you'd just need to attach it to whatever tubing you use for transferring the chilled wort from the boiler to the fermenter.
I don't recall seeing any such design (at least not on the Internet) and the wheels started turning in my head and it wasn't long before I came up with this:
Essentially, you have a 1/2" copper tee with 1/2" caps soldered on all ends. A 3/8" hole is drilled in each of the caps and a short piece of 3/8" copper is soldered into the hole. At one end of the tee, you insert your stainless aeration stone attached to its tubing (which is 5/16" OD in my case) - to seal it all up, you use a 3/8" compression to 5/16" compression fitting.
Offhand, the only potential problem I see is the right side of the tee where the aeration stone and tubing is attached - you may have to use larger OD copper tubing (and the proper compression fitting) in order to insert and later remove the stone. Another possible issue is how well the compression fitting will seal around the plasting tubing for the airstone - it may not work that well, in which case I'd get a short piece of polyethylene tubing (the milky white stuff used for running water to refrigerators) - I know it'll seal up with the compression fitting and would just have to find a way to attach the airstone to it.
Anyway, comments and suggestions are welcome - this is essentially a stream of conciousness on my part and I don't even know if it'll work at all. If you see some problem that I've missed, please let me know! And if you know of a better way of doing this, I'm all ears!
Update: 4/15/98: I never did get around to building this little gadget - but I've gotten lots of feedback from people, and the main concern that was voiced was that there was the possibilty of wort flowing backward through the system due to the air bubbles. That possibility can be eliminated by making the outflow side a larger diameter than the inflow side, thus keeping the pressure lower on the outflow and encouraging the wort to go that direction. I had always planned to use the aerator in line with my wort pump so this was never really a concern.