Okay, long post follows. I used the system today, some good, some not so, lots of learning by doing so here goes. First, this is what the system looks like:
Kind of a mutt system: My old MLT is still doing duty as an MLT. I've hooked up a pump, a RIMS tube and a controller, all joined by 1/2 inch ID silicone tubing (more to come on that later). I built it on a restaurant table SWAMBO got me for Christmas for this purpose, having shortened the legs by 8". The components:
Just a simple little MkII pump. I have a throttle valve on the outlet and a system drain on the inlet. It's all quick-connects, 1/2 inch. They work fine at my scale. The drain is a nice little attachment, when I need to switch out hoses I can drain them at the bottom of the system. I run the wort using the pump through a RIMS tube with a 1600 watt heating element:
It, too has a throttle valve. You can see the temperature probe at the bottom left. It is on a PID controller:
A few issues programming it but aside from that, it worked like a champ. I used a manifold in the mash tun to distribute the runnings evenly. In action with wort in the lines it looked like this:
I started running into trouble here: The 1/2 inch lines were too big, the pump didn't have the capacity to keep them full with wort draining through the grain bed, no matter how I set the throttle valves. So I replaced two of the lines with 3/8" tubing. It'll fit on the 1/2" barbs by the way. Once I did that, less air, less cavitation and much smoother operation. I'll have to replace the line from the RIMS to the tun but that's okay, it did well enough, I got super clear wort. But eventually the step mash was over and I could run off the wort:
I have a plate chiller but my kettle is not yet ported (step bit and cutting oil are coming soon). So I used the good old fashioned gravity drain. Once this part was over, I sparged - batch sparging still, even with this newfangled pump setup, reconnected my system to recirculate the sparge (RIMS shut off), then ran that out. Finally for Craigerr, some boil porn:
A good start. Not everything went as I'd planned and a few errors run me into a lower than expected efficiency (I got my wort too hot and likely denatured my enzymes a bit earlier than usual). Lessons learned: Bigger tubing isn't necessarily better: Backing down to 3/8" ID tubing will help out a lot. I got a lot of air in the lines this brew, I'm hoping that hot side aeration is indeed a myth. Rice hulls: A stuck mash with this system is a scorched mash. If you build something like this, put in a bottom drain. You'll thank yourself when it comes time to clean up. It's less work and will be much less lifting once I have the kettle ported. When you build your system, you won't think of everything but with a little ingenuity, brew day will work. Finally, keep good notes so you'll know what to do (and not do) next time. Next brew will be smoother.
