distillate turning grey/black

[tomm292]

I have several batches of sweetfeed to run, and started them on a newly built pot still. The still head was cleaned with a vinegar water run followed by a sacrificial run. After collecting the spirit on the first run i proofed to 55% then added some oak. Within minutes the distillate was starting to turn grey, and after an hour almost looks black. The oak was medium toasted, with a little bit of french oak toasted shavings. I have used this combination on my rum produced from my other still head when i ran some and beautiful amber colors resulted. The rum was aged at 65%. The sweetfeed recipe was followed, and no nutrients were added, racked off the grains and cleared in a carboy.
The new still head has a copper column, then a stainless 90 degree elbow, followed by a copper reducer to the condenser.
I havent read anything like this on the forum so i am stumped on what went wrong. Could it be a problem with the wash, or something from the still head ? Maybe the stainless fitting, its the first time with a stainless piece in my still, other than the boiler tank.
Any help would be appreciated, as i dont want to run more before i figure out what is going on.

If this is posted in the wrong forum, my apologies .

thanks

[Truckinbutch]

I hope someone has answers for your question . Kinda beyond me .

[still_stirrin]

Tell me about your wood. Was it new wood, or previously used? Did you rinse it off before throwing it into the jar? This sounds like something washed off the wood and into your spirit.

I don't think the sweet feed (recipe) is the cause. I think its the wood.
ss

[Truckinbutch]

Tell me about your wood. Was it new wood, or previously used? Did you rinse it off before throwing it into the jar? This sounds like something washed off the wood and into your spirit.

I don't think the sweet feed (recipe) is the cause. I think its the wood.
ss

I never had this happen with sweet feed myself .

[tomm292]

i did up a batch of medium toasted oak, and i have used them in about 5 batches of sweetfeed and 14 of rum. No problems with those ones. I had about a half liter that didnt make it into the jug, so i dropped just a couple of the toasted french oak shavings ( from the brew shop ) into the distillate, and almost right away you could see dark wisps starting to color up the liker.
I have just been looking through all the pieces of the still as best i could, and one section of copper seems to have a bit of a build up on it. Prior to assembly , i attached steel wool to a coat hanger, and ran it with my cordless drill, vinegar and water to clean all the pipe and fittings, prior to the cleaning and sacrificial run.
The section in question does look a little blue, could this have gone into solution and be reacting with the tannins in the oak ? the distillate came off the still crystal clear.

[still_stirrin]

Soak the oak in water for 30 minutes and rinse good before putting it into your distillate.

Again I ask, was the wood "new" use? Or have you used it before? And I'm asking about these specific chunks.
ss

[yakattack]

Pictures of everything would really help here.

[still_stirrin]

....i have used them in about 5 batches of sweetfeed and 14 of rum...

This is why I'm asking...its unclear if the wood chunks were previously used and how many times, if they were.

[tomm292]

The oak was new, not previously used. The oak sticks were toasted medium, and the french oak was new out of the pack from the brew store, some was used on my rums with no problems. The sweetfeed is so dark after a couple hours that you can not see through the jug. For the little amount of oak used , it should have barely any color at this point. I am leaning towards thinking that it must be a copper sulfate problem

[tomm292]

i will post some pictures tomorrow when i have time, thanks

[Truckinbutch]

My experience with wood , logging , sawmilling , and woodworking is that mineral stain goes up the tree and metal (iron) goes down . Lumber graders are quick to spot this and so are stave yard buyers . Substandard wood would be my first guess .

[tomm292]

I think i solved my own mystery. I grabbed the wrong flux, it wasnt the water soluble kind. The stuff is a pita to get clean. I am fairly confident that there is still residual flux that wasnt removed in the cleaning procedures, and the combination of the flux and alcohol reacted with the oak to cause the discoloration. I have it soaking in backset now, and was thinking another soak in vinegar or citric acid would also help. Fork me, what a bone head mistake.

[aircarbonarc]

At least you didn't use plastic PVC pipe and caulking.

[MrBee]

Prior to assembly ,"""""" i attached steel wool to a coat hanger""""", and ran it with my cordless drill, vinegar and water to clean all the pipe and fittings, prior to the cleaning and sacrificial run.

Um, me thinks the STEEL WOOL may have something to do with it. Some particles may have gotten embedded in the copper .
The flux may be the issue also .

[thecroweater]

It was clear and then turned black? It ain't ya still. Some barrel Kant boards in the heads are fitted together with double end steel nails. Not an issue for the keg but if they are pulled apart and chipped the oxidized iron infused wood will turn spirit a weird grey colour