Silver in still/distillate takeoff

[jon1163]

I run a 15 gallon keg boiler and an 8 gallon keg thumper with copper piping. I've always kept my still clean and wash the copper out after each use with water. I followed all cleaning protocols from our website after the build and have numerous runs through the still with never a problem.

I recently ran an 18 gallon batch of still lifes rye as follows:

18 gallons water
15 lbs flaked maize
6 lbs flaked rye
12 lbs malted rye
3 lbs malted barley
3 handfuls of oyster shell

I cooked the corn, flaked rye, and barley for about an hour and a half and then cooled to my high temperature enzyme pitch. And 150 degrees I added The Malt and wrapped it up for two and a half hours. I topped it with water to 18 gallons, added my glucoamylase at about 122 degrees, aerated, and pitched 1.5 ounces of SafaleUS05 at 80 degrees. I added 260 g of damp rinsed oyster shells or roughly three handfuls.

My iodine test was good and my starting gravity was 1.063. After 5 days I finished at 1.00. I used my mop bucket and squeezed out all the grains then I racked it into a couple buckets and let it settle out. Today when I went to distill I racked off the clear beer into my boiler topped it off with some honey bear bourbon feints and put just a bit of clear beer and a little more bourbon feints into the thumper.

* I noticed that my mash was very thick even the clear beer. I'm not sure if this is typical of a rye because I don't make them very often but it was definitely thicker than my bourbon mashes.

I started pulling distillate at 78% ABV and pulled off 27 pints before I shut it down at 48% ABV. They are covered and airing out as I write this.

My distillate smelled great and tasted wonderful as I went through the run.

I finished up and started breaking down my still and that's when I noticed the silver sludge. I had already drained my boiler so I didn't see anything in there as I wasn't looking or suspecting anything amiss. In my copper takeoff pipe where it attaches to my boiler it looked like the inside was scratched with a wire wheel. I stuck my finger inside and out it came with a bright silver sludge. It didn't really smell like anything... I wasn't brave enough to taste it.

It seemed to be isolated to just inside the takeoff and didn't appear to make it any further into the pipe, into my thumper, or into my condenser.

I'm just wondering if this is anything to be worried about.

I do have a theory of my own. I think that it might have something to do with the oyster shells. The silver had that kind of glistening shine kind of like oyster shells do... shrug. The sludge in my settling barrels was really thick like compacted silt.