We’ve nearly managed to complete our build of a 50-liter automated brew kettle, and now only need to build a stand for it and take it for a test brew. I’ve grabbed some pictures of the construction and our testing with tap water:

These are the pots used for the kettle. The bigger one is 50L and will function as the outer kettle, while the smaller ones are 35L and will function as malt and hop ‘bags’.
 
 

One of the inner kettles with a removable stainless steel mesh.
 
 

The outer kettle has the output in the bottom of the kettle to minimize wort loss. We had some problems with leaking, but fixed that with some food-grade silicone.
 
 

The 3500W ultra-low-density heating element is installed and tested for leaks.
 
 

Planning and building the control box. We installed both a heat sink and a fan for the SSR, to prevent overheating.
 
 

Control box all wired up.
 
 

The first test. The PID is to the left, temperature at the sensor is 26.8 (the LCD was apparently updating as the photo was taken, hence the weak numbers), while the thermostat is set to 45.0. The red switch is the main power switch, the middle switch is power for the heating element, and the third switch is for the pump.
 
 

The test setup. We still need to build a stand for the kettle, otherwise everything is working. The kettle was able to keep temperatures steady and heating of 40 liters of water was surprisingly quick.
 
 

The water is boiling, and the thermostat is showing 100.1 degrees C, not bad.

The first test brew with the kettle will most likely take place in a week, when we are brewing up a 25-liter batch of Pilsener (with no-sparge, the maximum batch size for a 1.050 beer should be around 28-30 liters with this kettle), that will be hopped with Saaz and Hallertau Mittelfrüh, and fermented with Saflager W-34/70.