So my last batch was my first 10 gallon batch and I wanted to cool it down as quickly as possible. I had read Jamil's article on MrMalty.com about his whirlpool IC and was really impressed by how fast he said he was able to get down to pitching temps. However, I didn't want to spend money on a pump and I don't have a valve currently installed in my kettle either. So I thought about it a bit and realized that Jamil's whirlpool chiller is simply preventing the temperature stratification of the wort that occurs when the liquid closest to the coils cools down faster than the liquid near the center of the pot. This is why so many people go through the trouble of building the ribcage style IC since it distributes the cooling coils more evenly throughout the wort. I figured that if I could find a cheap and simple solution to preventing temperature stratification then I could avoid the cost of a pump and the pain and complexity of building a ribcage chiller.
So my genius solution of course came from Home Depot, like most of the great equipment ideas that homebrewers have come up with. I bought this helical paint mixer designed for a 5 gallon bucket.
It's made of polypropylene so it's pretty resistant to the boiling wort and the ph levels. I chucked it in my drill and ran it at a very low speed and combined with my 50 foot 1/2" dia. IC, I got 10 gallons of wort down to 65ºF in about 15 mins. The wort got down below 140ºF in the first 5 mins. I took temp readings in different areas of the wort and it was clear that the temperature was even throughout the entire mass of liquid.
I figured that I should share this tip with you guys since it's very easy to do and saves a bunch of money. I was concerned with hot side aeration so I made sure to keep the drill on a very low speed and to keep the head of the mixer deep in the wort. I also checked to see if there was any sort of funnel forming that would introduce oxygen into the wort and there was no funnel visible, just a nicely moving wort. I also just kegged the batch and did not taste any off flavors associated with HSA.
Give it a shot on your next batch and I hope you get the same great results as I did.