It may be mid-winter here in Melbourne, but yesterday the sun was shining, we were brewing, and mostly HERMAN did the hard work for us while we sorted out fermenters, cleaned a few bits and pieces and reflected what to do with a Belgian wheat that was over-bittered.
We were due to make our American Pale Ale last week except that we were distracted by the HERMLET project (see previous blog). But this week we loaded our wort with Cascade hops and enjoyed the sweet fragrances that brewing brings with it. This beer follows the same recipe from one a few weeks ago where we used Nelson Sauvin hops in place of the Cascade. The Lady Nelson Ale is already a hit with all in this household.
Anyway, after a few minor tweaks, HERMAN did his thing again and this time the PID control worked like a charm.
In the graph above, the dark blue line at top is the hot liquor tun oscillating gently around the set target of 80 deg C. It does not have PID control. The dark red line shows the mash temperature and heating is controlled by the PID controlled heat chamber. The red line is smooth and hits target perfectly, even though the green line still oscillates. This means the PID could still do with some minor tuning, but we are very happy with the net result.
Next weekend we will either brew a batch of Belgian wheat beer to revive our last one (which has too much bitter pith from citrus fruit in it), or we will continue work on HERMLET.
Dream-Invent-Create 