I recorded my first effort at creating a sour beer, a Berliner Weisse. I used Greek yogurt, with active cultures, to introduce the Lactobaccillus into the fresh wort. Once the wort was soured, after 7 days, I ran it though a standard boil to kill the lacto and hop the beer. I then fermented it normally
Before souring, I heated the wort to boiling for under 10 minutes. I did this to kill of anything that may have been in it and get a clean souring. I then cooled it in the boil kettle and added the yogurt to sour it.
I kept it in the boil kettle at between 120 and 100 degrees using my HLT and immersion chiller (I lowered the temp after a few days). I didn't want to use the boil kettle's heating element because I thought it would kill any bacteria it touched.
To maintain temp I plugged a pump into the 120v heater outlet on my brew controller with the temperature sensor in my boil kettle controlling it. I usually use this outlet for my 120v RIMS heater. The HLT temperature was controlled with another controller and kept at 125 to 110 degrees (I lowered it when I lowered the wort temp).
When the wort cooled its sensor turned on the pump that circulated hot water from the HLT through the wort chiller immersed in the wort. Heat was transferred to the wort and once it reached temp the pump shut off. This worked great!
