I have a 48-quart rectangular picnic cooler, and 20ft of 1/2″ CPVC pipe, ten tees, eight elbows and two valves shipped today and should arrive Thursday. The plan is to build a rectangular manifold as shown on the second page of Palmer’s Appendix D, with four lengthwise slotted segments of pipe, connected to the two shorter, unslotted end segments, with the outflow pipe going out through the cooler’s drain.

I’m also going to want to put a thermometer through the cooler wall so I can get good temperature readings on the mash, and I actually got twice as much pipe, and twice as many fittings, as I’ll need for one manifold, because I want to build a second one to affix to the underside of the cooler’s lid, with its “tail” pipe sticking up through a hole in the lid: that should allow for even, gentle distribution of the sparge water over the grain bed.

An extra wrinkle I hadn’t quite thought of at first is that I’m going to need a bigger brewpot. Currently I have a 20qt stainless pot which has served me well for many an extract brew, but for a 5-gallon all-grain batch I’m looking at 6 – 7 gallons of wort at the start of the boil; it might be possible to do the boil in batches, but I don’t really like that idea much, so I’ll have to look around for a decent price on a 32qt pot. I was thinking that since stainless gets so expensive at that size (I don’t think I’ve seen one under $75), enamel might be a good way to go, but I’ve hardly been able to find anyone selling enamel stockpots at all. If stainless turns out to be the only option, I guess that’s how I’ll go; probably I should get on some homebrewing mailing lists and look for people selling used equipment.

At any rate, it should be a fun an interesting project. I’ve got (nearly) all the parts either here already or on the way — picked up a hacksaw and some CPVC primer and cement at the local hardware store on the weekend — so I should be able to get working on it soon. I’ll put up pictures here as the project progresses, in case that’s of interest to anyone.