Black Trub In Last Pour

[dnye]

I had a keg kick recently and the last glass that came out with all the trub from the bottom of the keg was really dark, almost black. I have never seen this before and was wondering if anyone had any ideas as to what causes this and if it's a problem. The keg tasted fine the whole time and even the last glass smelled fine it was just really dark. When I opened up the keg to clean it the last bit of trub was also black. See image below.

A couple other notes, this beer was an oberon clone and we used yeast harvested from oberon bottles for the brew. Also the batch was split into 2 separate kegs and the black trub was seen in the last beer of both. No other discoloration before it kicked.

Any thoughts or ideas would be appreciated!
Thanks!

Black trub in keg

• dnye
• Oct 14, 2019

 

[RPh_Guy]

Any new stainless steel equipment parts by chance? Did you recently use any new cleaning chemicals?

 

[dnye]

I did just get a new ssBrewTech fermenter. I cleaned it with TSP, which I have never used before. I'm guessing this could have caused it? I think this was either the first or second batch using the fermenter. I just put another batch in there on saturday. If this is the culprit, if it shows up in another beer, how do I clean it out? Obviously I have finished the keg, do I need to be worried?

 

[RPh_Guy]

All I know is that the black slime from stainless doesn't seem to affect the beer and it'll probably go away after the first batch.

 

[Vale71]

Since it seems to float on the beer I would say definitely some kind of oil residue.