Single Kettle Recirculating Systems
The recirculating BIAB system is my favorite and my personal choice for my own home brewery. It's simple, space and time saving, and there's a lot less cleaning involved. To build this system, all you need is a brew stand, the BIAB recirculation kettle kit, a pump, and the hose connections. You'll also need a controller to maintain the temperature of your mash.
By recirculating during mashing and using an appropriate brew controller, you can program your mash stages and maintain the optimal mash temperature. After boiling, you can use the empty 400 micron brew bag as a whole kettle filter to filter out hops and hot trub. It works great and allows you to completely empty your kettle into the fermenter.
After your wort is chilled, you can open the lid until the recirculation return tube is above the wort level and carefully oxygenate your wort by expsosing it to air.
It is very easy to connect the pump at the inlet side with a silicone tube or, as shown below, with a short (10cm) stainless steel spool. You can also install a sight glass vertically with a 90 degree bend at the pump outlet.
I completely drain the pump circuit after mashing so that no unboiled wort gets into the finished batch.
For the 85L Solo (below left), I recommend switching to 1" fittings and 19mm ID tubing. For the 85L kettle, a 10cm extension for the inlet side of the pump is sufficient. For the 115 liter kettle (below right), you'll need 12-15 cm length to have enough room.