On the Direct Fire Brew house, can the burner be modulated to control temps?

Yes, the burner can be modulated directly by the main control panel anywhere between 5-100% of total output. This makes it easy to dial in a full rolling boil. 

Furthermore, the control panel can also modulate heat based on a specific set temperature.  

For example, if the brewer would like to brew a kettle sour, they can hold the brew kettle at 110 degrees while adding lactobacillus to the wort before their boil.