Originally Posted by JoeSpartaNJ
Bubbles only around where the racking cane meets the siphon tube, and like I said...not alot of them.
The increased pressure in the carboy is from using the "blow" siphon, introducing air into the carboy to start the siphon. That is what made me think that the beer might be getting oxidized.
Introducing AIR or CO2? If you're just hooking up an aquarium pump to blow it out...that's a big issue there.
If it's CO2, then purge your keg prior to siphoning (or bottles), and/or take the siphon tube off and buy a tube that's 1/16" to 1/8" smaller ID. Attach to the racking cane by either gently heating with a lighter or dunking the end of the tube into hot water for 5 seconds or so and you'll get a nice tight seal and no air intake. (If you see bubbles after this, it's due to the entrained CO2 in the beer you're transferring, not a leak. You could also be seeing this with a tight clamped set-up.)
Other usual causes of oxygenation:
1. Splashing beer while transferring: make sure siphon tube is all the way to the bottom of the vessel being transferred to
2. Oxygenating at too high a temp after boil: don't vigorously stir until below 90 F when cooling
Those are the two biggest in addition to non-purging of vessels.