Help! My element scorched - but how? What happened?

[PalCabral]

Hiya distillers.

Just had the stripping run from hell. Already from the start there was a weird smell coming out. When the foreshots came so did vapor fumes, out the spout. I increased the coooling to max and the fumes dissipated but the smell continued. A foul acrid metalic smell, the likker too. I still ran, stupid me, always carry on. But after 1 1/2 hours and 3L of disgusting smelling distillate I pulled the plug.

After emptying the still I find the element covered in black charr, or maybe even more like covered in burnt crystalized sugar. That's more what it is, burned sugar. What the hell happened? What could have made the element charred like this? And it still worked, it kept running, heating up the wash, producing low wines until I turned it off.

The wash that went in was a high rye bourbon mash. I tasted it before it went in and it tasted fine, nothing funky with it. It had fermented out totally, FG 1.000, so there was no residue sugar in it. And I always pay attention to not syphoning over any yeast trub or solids from the fermentation bucket to the boiler. But when I emptied the boiler the bottom was full of fatty, oily, wash. It wasn't sticky or viscous, but it looked like a fatty soup or chicken stock.

I really need some help to get to the bottom of this.

1. What happened here? Can a high rye bourbon mash have the potential to do this? I've heard about some grains having a lot of oils but I really have no reason to thing there was something funky with the mash. I used butter in the boiler to prevent puking - could this somehow be a culprit?

The only difference in my set up today from any other day, is my new beautiful onion head. I used it yesterday when I did a spirit run of a wheated bourbon, there were no problems with that run. Could residue from the onion drip down into the boiler and create this mess? After the run yesterday, I flushed the inside of the head, like I do with all modules after a run. There were no smells or funny business with the onion's inside. Neither is it now, after the disastrous run. And the element looked fine too. I gave it a rinse as well yesterday.

2. Can I salvage the element? Can I put some acid or something on it to clean it up or is it buggered? It actually still works - could a vinegar run do something positive to it?

Appreciate your help here.