Chasing a kind off burnt flavour

[Marlin1]

I'll start with this.
1.5m x 56mm reflux still.
50l keg pot.
LPG burner.
Tpw washes. They are stalling at 1.010 so I ran them
I messed it with a sg of 1.090. My bad missed calclatored.
That why I thought after 3 weeks just to high a abv content.
Anyhow
I've changed the condenser and run it a few time prior to this issue so I think it's not the condenser.
The problem I have is the is kind of a burnt tast to the spite.not bad it's just there. Hasn't been with one's prior?
The condenser looks like it's running hot and the copper looks burnt. Dark with a ting of purple. I soaked it in vinegar to clean it prior to the last 2 runs. So I can rule out it was dirty.. I've attached some pics OT the condenser after 2 runs its starting to turn purplish again.
Output tem at the outlet it 80deg. Output water temp I'm not sure of but it's steaming in the cool night.
If I turn the condenser water flow up it cools the reflux to much. Output tem drops below 78deg.
seems to be refluxing right.
Any ideas??
Help appreciated

[The Stig]

Scorched ??
The reason I’ve never liked gas are 2 fold, it’s all too easy to scorch the mash/wash and it’s bloody dangerous.
Oh and could I make a suggestion ? Please proof ready before posting . We won’t tolerate txt or Facebook type chatter here :handgestures-thumbupleft:

[bluc]

This is obviously a reflux still. No way you are scorching the coil with steam from the boiler. If running a gas boiler, direct fired, more likely that is the.source of the scorch and that flavour is carrying over.
Anything burnt in bottom boiler once emptied?

[The Stig]

Exactly what I said above

[Marlin1]

No. Nothing burnt in the bottom of the boiler keg.
Not even a burnt mark.
I run the boiler at around 93-95 degrees.
Below 90 there's not really any flow.
The last run. The burnt flavour was strong at about 2.5 l output into the run.
I collected the rest as tails. Ended up with 2.5 l of tails till it got to 30%

[chipboy]

just because the mash temp is a nice 93 does not mean the spot temp on the boiler directly above gas flame is not a lot higher, Stainless in not a good heat conductor so your not going to go near the flame, you're largely unaware. Hence some scorching. Same with elements in the boiler, energy density can lead to high surface temps and scorching. This i know.

[bluc]

:text-+1: no way a condenser with its cool water flowing through it can scorch anything.

Thats the reason the big on the grain distilleries heat with steam.

[B-Man]

Please proof ready before posting .

:o

[Wellsy]

Plus 1 to what Bluc and Stig said. If it is not fermenting dry perhaps there are more particles, they don’t need to be big, that are scorching in the kettle. This was my issue when I used angel yeast and did not let it settle enough.