I am new to brewing and I wanted to find a way to keep my fermenting brew cool. I experimented by taking a cardboard box measuring 32"H X 21.5"D X 16.5"W, went to Menards and boutght 1.5" foam housing insulation, cut the foam insulation to fit the dimensions inside the box. I cut away on side of the box so I can access my cooling elements and beer easily. I fashioned a handle out of packing tape. The inside of the box is large enough to fit both my primary fermenter (a 6 gal. Better Bottle) , my secondary (5 gal glass carboy), and my plastic, water-filled containers (frozen) which I use as a cooling element. I exchange the cooling elements in the moring and in the evening. I was surprised to see that as I was replacing the cooling elements, they were still partially frozen.
Surprisingly enough, the box stays pretty cool(so far, it reliably stays in the low to mid 50's). I think I could get the box even cooler if I use a salt/water mix and freeze my plastic cooling elements in my deep freezer and then use multiple cooling elements in the box with the fermenting brew.
I am using a Northern Brewer extract kit for a Kolsch, and I plan to follow the fermenting schedule from a post on the NB forums...
>>>Primary (1 week) and Secondary (2 weeks) at that hi 50s temp and then drop it to upper 30s-40 degree range for 4-6 weeks (cold condition). If I hit my gravity in the primary before moving to the secondary -- I go straight to the cold conditioning. Then bottle it at 70 degrees and leave at 70 for 3 weeks. Then put the bottled brew back in the fridge at 33-40 degrees for at least 2 weeks, but preferably longer if you can stand it.<<<<