Recirculating Steam Infusion Mash Tun

I have been an all-grain brewer for a few years now, and have been consistently hitting 75-80 percent efficiency using a single-temperature rest. My mash-out process is usually to take the first runnings, then batch-sparge with water at a temp to bring me up to 172 for the sparge).

I am very happy with my extraction efficiency, but my lighter-colored brews tend to suffer from slight chill-haze. Therefore, I am thinking a protein rest will help me here.

My set up includes a 10 gallon round mash-tun, which is typically too small for bigger beers, let alone step-infusions. I sometime use a smaller 5-gallon mash tun in conjunction with the 10-gallon tun, then combine both in the kettle to get my 13.5 gallon pre-boil volume. After lots of research on the topic, I figured steam-infusion would be the best was to incorporate step-mashing in my setup.

This Thread was very helpful in getting my set-up worked out.
http://www.homebrewtalk.com/f51/easy-steam-infusion-mash-system-25974/]

Recirculating Steam Infusion Mash Tun

I have a 16 quart pressure cooker that I use for canning starter wort... I made a slight modification to accommodate the fittings.

PRESSURE COOKER MODIFICATION

The cooker had an emergency pressure release (rubber stopper) which is where I relocated the pressure gauge, then I put my new steam-valve assembly in the hole previously used by the pressure gauge. I was going to tap another hole so I can keep the pressure-plug in place, but figured the primary pressure-relief weight (calibrated to 15 psi) plus my fittings would be sufficient as long as I monitored the pressure gauge closely. On my kitchen stove, I can barely get up to 15 psi.. but on the Hurricane Burner in my brewing area, I will be able to blow thing thing sky-high if I am not careful.


STEAM MANIFOLD
I picked up a 10 foot roll of 3/8 copper from HD, and used about 3 feet of it to make this manifold. I simply crimped the end, and drilled about 16-18 holes using a 1/16 inch bit. The bit went thru like butter. I alternated the direction of the holes... one up, and one at an angle toward the center. A test run with water and I had some great bubbling. I cant wait to get this thing into some grist!

My plan was to stir the mash like mad while I was steam infusing and watching the temp, but I figured I would try recirculation to help keep heated mash mixing.

So using my existing March 809 Magnetic Impeller Pump I built a simple return manifold using some 1/2 inch I.D. braided hose.

RETURN MANIFOLD

I simply curled a 2-foot piece of braided hose onto a tee, then attached it to a shepherd's hook I built because I was tired of lifting sparge water.


The holes were drilled at 90 degrees (up) and 45 degrees (toward the center)... which really seems to distribute the water nicely, especially when just under the surface of the liquid as in this picture...


I am also going to use this set-up to recirculate during the cooling process (switch out a manifold for a straight or curved piece of tubing). I have an immersion chiller which I hook up to a sump-pump and ice-water for the last bit of cooling. From what I read recirculation will really speed up the cooling.