grain oils

[creekwaterbrew]

Howdy, I have a brew that just finished cold crashing. When it was brewed, I noticed a rainbow hue in the bubbles during mash runoff. I am pretty nervous that it could be chemicals or oils from the brand new stainless steel pot that I used. I rinsed it out with star san but didn't scrub prior to use. I've heard that grain husks release oils but would you see them in the bubbles like that? Thanks.

 

[mors]

You should always clean new equipment with a cleaner prior to use. Star San is not a cleaner. For stainless items I like to use dish soap first (to remove oils from manufacturing) then Bar Keepers Friend and let air dry. This will passivate the metal and prevent any kind of rusting etc. After than if it's a kettle I don't typically wash my kettle at all.. I just rinse it off when I'm done with it... maybe occasionally it gets a PBW/Oxy-clean soak.

I've never had oily looking wort.

 

[two_one_seven]

Soap like bubbles(these can be rainbow like due to the refraction of light)in the mash means that you got conversion during the mash. I am assuming these were in the bubbles in on the grain when you opened the lid on the mashtun? It's a good sign.

 

[Hex23]

I'm sure there's a logical explanation for it, but if it makes you feel better, I see this on all my mashes and never have any off flavors like what you'd expect from cleaning chemicals.

 

[creekwaterbrew]

Thanks for the reassurance. I notice the rainbow hue in the bubbles in the mash run off.

 

[Hex23]

Thanks for the reassurance. I notice the rainbow hue in the bubbles in the mash run off.

Yes, that's where I see it too, in addition to the bubbles on top of the mash.