Ok so I’m going to dip a pinky toe into the wood, electric and gas debate. I’ve made beer and ran shine on all three for years and here are my personal views. Mind you I’m not putting down anyone that prefers to use any heating source they want to.
Wood - I’ve used wood to heat mash water, boil wort for beer and run a small still. There is something about brewing or running shine outside with the smell of a wood fire that’s kinda primal. It’s a traditional way to run a still or to boil wort so there is a historical connection and I’m happy to see folks are keeping this tradition alive. But it IS inefficient and can be dangerous. There is a reason why shiners and beer makers switched to gas as soon as they could get their hands on propane tanks and burners.
Propane - started my home brewing and professional career with propane like many brewers have. I also fired my still with propane. Like wood there IS a difference when it comes to caramelization Vs electric. Moving from propane to electric I did detect a difference in my award winning stout pagan. I would actually fill my boil kettle 1/4 of the boil volume just to get some extra caramelization and flavor. Something you can’t do with electric elements. Also running my sweet corn shine recipe there is more of a “corn bread” aroma. With proper venting and shielding propane is pretty safe and with some skill temps can be regulated with the right regulator and air intake valve.
Electric - more efficient than wood or gas, easy to regulate temps and is more convenient. No tanks or wood to stack so setup times are minimal. You lose some caramelization effects since the element actually creates a vapor halo around the element. The key is to use ultra low density elements. They spread the elements energy over a larger surface area which helps with scorching and distribution of heat throughout the kettle or pot. Now the the entire scorching thing is more complex than you might think. If an element is cleaned properly between runs scorching isn’t a huge concern. You have to think about what is happening when an element is turned off. The vapor halo disappears but the element is still hot. So you will have localized “baking” on the element. Which is easily cleaned off between runs. The only issue I have ever had with scorching is when I was too lazy to clean the elements between brewing sessions or liquor runs.
In the end folks that run on wood get my respect bc they are keeping a tradition alive and they can be a go to resource for knowledge. But as a professional brewer and distiller I can say it just doesn’t have a place in mass production. But it sure is a rewarding way to stay grounded and learn how the old timers used to make beer and shine.