Grey foam and metallic taste in RoboBrew

[Murphyslaw11]

Hey all. Last night I brewed a Hefeweizen in my RoboBrew. All seemed to go well until the boil. As the boil started, the hot break was grey with black streaks (prior to hop addition) I stirred with a metal spoon at the bottom of the kettle, thinking I may have crushed the grain a bit fine and scorched it. The foam was replaced with normal light brown foam. I decided to stir every 10 or so minutes for my 90 minute boil. The grey foam came back at the end of the boil.
My pump was clogged with grains as I was cooling it through my coil, so I thought it had to be burned grains, but the stuck grains were not burnt when I cleaned out the kettle. I also didn’t have any black spots on the bottom of the kettle, so I’m stumped.
I tasted the wort and it tasted mostly normal, but with an unpleasant flavor at the end. It seems sort of metallic or maybe burnt.
Fermentation is also wicked slow today (not sure if it is even going).
Any advice on what to do or how to properly diagnose?

 

[jdauria]

Was this first time using Robobrew? It is was, sounds like you did not give it a good cleaning before first use and it may have had machine oils still on it. All new stainless should be washed and passivated Passivating Stainless Steel Beer Brewing Equipment to Prevent Corrosion If not the first time, then I am stumped.

 

[9Kegs]

Are you able to inspect the element? You will see scorching and black deposits if burned. I've had 2 dumpers in 3 years and they both involved wheat when the percentage was more than 50%. I constantly whirlpool while recirculating. This happened WITHOUT dry firing the element. If it is burned you will taste it.

 

[Murphyslaw11]

Was this first time using Robobrew? It is was, sounds like you need not give it a good cleaning before first use and it may have had machine oils still on it. All new stainless should be washed and passivated Passivating Stainless Steel Beer Brewing Equipment to Prevent Corrosion If not the first time, then I am stumped.

Than

Was this first time using Robobrew? It is was, sounds like you need not give it a good cleaning before first use and it may have had machine oils still on it. All new stainless should be washed and passivated Passivating Stainless Steel Beer Brewing Equipment to Prevent Corrosion If not the first time, then I am stumped.

It was my first time using this RoboBrew in particular, however it is not a brand new system. I bought it used from someone. I made sure to clean it beforehand and then let Star San sit in it for a bit. I also boiled water in it the night before to ensure everything was running well. No issues and no sediment/darkening of water. I’ll have to inspect the element when I get home

 

[Murphyslaw11]

Are you able to inspect the element? You will see scorching and black deposits if burned. I've had 2 dumpers in 3 years and they both involved wheat when the percentage was more than 50%. I constantly whirlpool while recirculating. This happened WITHOUT dry firing the element. If it is burned you will taste it.

I also whirlpooled the entire time while recirculating. I have not yet checked the element, but I will when I get home and report back here. The wort definitely had an off aftertaste, but I can’t tell if it’s burnt or metallic or neither