Coloured bubbles during mash

[rukkus]

The last couple of times i have mashed in my cooler there has been a bit of a coloured slick on top. A bit like you see from oil. It doesnt look bad but i'm curious if anyone else sees this? I'm hoping its not something coming off tap connectors or the plastic from the cooler.

[Metattron]

You making Skittlebraü?

[johnrm]

Normal.

[rukkus]

Phew, its only recently i've noticed it. Not used to the sun shine when brewing i guess.

[rukkus]

Anyone any idea what causes it? Oils from the mash...?

[johnrm]

This is caused by diffraction of light.
Protein in the Wort causes high surface tension and so, bubbles.
Some light reflects off the surface of the bubble, some gets through.
The colour of your wort combined with microscopic particles will dictate what does and does not get through.
What does get through in turn reflects off the wort surface.
Some of this goes out and some is reflected in again.
Moving rainbow like colours are caused by the constant movement of the liquid.

actually, bo11ocks.

its magic 

[Ciderhead]

Or Fairy Liquid

[DEMPSEY]

Or Fairy Liquid

As CH has said,you should check if you have a Fairy fort close by

[Ciderhead]

"Fairy Forts" isn't that some kind of release post homosexual activity described by someone from D4? 

[johnrm]

 

[DEMPSEY]

"Fairy Forts" isn't that some kind of release post homosexual activity described by someone from D4?

Not sure,I'll check with the lads and lassies next time I pick them up :