Wierd color during boil

[JuanKenobi]

I made a starter earlier tonight and ran into something I've never seen before. After the initial foam settled down and the boil was stable, the remaining foam turned to a charcoally color and some similar colored gunk (similar to hop pellet residue but drier) got stuck on the sides of the pot above the boil line and on my stirring spoon. When I wiped some of it off with a paper towel it looked almost like ash. I'm not really worried about it since it's just a starter. If it's obviously ruined I won't pitch it. Just wondering if anyone had seen anything like that before.

Nothing but DME and water in the boil. I did add yeast nutrient for the first time, but the dark foam happened before I added it. Any ideas?

 

[Aleforge]

That is really weird.... I would like to know also as it sounds interesting!

 

[JuanKenobi]

The pot I used is a vegetable steamer. I like it because it's tall and narrow. All I can think of is that maybe there was some soap residue from last time it was washed or vegetable protein maybe? The soap thing seems most likely to me since I've used the same pot to make starters before with no problems.

 

[BubbaK]

Could you have burnt the DME? I forgot to put the fire out before adding mine on one batch and it kicked up all kinds of black stuff. Took me a bit to realize what it was..

 

[obezyana1]

What is your pot made of? Is it scratched inside? Some pots (teflon lined ones in particular) have other metals under the coating and those metals can oxydize. The oxydation will then leech out into the boiling water. This may not be the case for you, but it's something to look for.

 

[JuanKenobi]

It's a SS pot. I just looked at it and noticed that there's still some of the stuff on the side of it:

The picture doesn't really show you the color, but that's the stuff. It's very ash-like when you scrape it off.

There is some discoloration in the bottom of the pot too. It's usually used with a basket inside to steam veggies so I suspect that the discoloration is from the steam water boiling off while still on heat.

I didn't think much of the discoloration as I've used the pot for starter worts before.

If it is oxidation of some kind there's still nothing to worry about right? It's just a starter and most of the liquid will get decanted before I pitch it into 5.5 gallons.

 

[obezyana1]

I wouldn't worry about it. As long as the yeast grow and you get a nice, viable starter then go ahead and pitch it. It will all work out fine. If it doesn't you will know not to use that pot again.

 

[JuanKenobi]

Starter took off like a rocket as usual, smells fine and all. I wasn't really worried to begin with, but I figured it couldn't hurt to ask. Everyone has such great insight around here. I hate to pass up a chance to learn something. Brewing an ESB later today with it.

 

[TexLaw]

If it smells fine, I would guess that it is fine. I really don't know what that crud is. I've seen the protein scum get an ashy sort of color to it, and that is sort of what it looks like on the side of your kettle, but I really do not know.


TL