What is this post-boil foam in my kettle?!

I brewed a ten gallon batch of single decoction Pilsner yesterday. I've been brewing all grain for a couple years now and have never seen anything like this. The boil went as usual and looked normal but after chilling the wort and racking it into the fermenter, I opened the kettle lid (I cover it after flameout) and saw a lot of white persistent thick foam along with the break material.









The wort that I racked into the fermenter was very clear and tasted fine, like normal wort. I tasted the foam and it was super hoppy with a very foamy consistency. It was a ten gallon batch with 10 ounces of saaz hops. I added two ounces of pellt hops right after flameout while whirlpooling.

I did two new things this brew.

1) It was the first time using a whirlpool valve i installed in the bottom side of the kettle.

2) I used the new "hop spider" I made witha 5 gallon paint strainer bag.

Also noteable was that I used 1.5 tablets of whirlfloc as usual and that it did chill very fast. I used a prechiller to pump cold water through the immersion chiller and got the temp from 212 to 170 in only a couple minutes.

There was no soap/cleaner residue on my equipment that could have cause d this. Everything was rinsed and cleaned thoroughly before use.

Has anyone else ever seen thie white foam after chilling using an immersion whirlpool chiller?

your new whirlpool is aerating the wort would be my guess...your return should be below wort level,,,or perhaps your pump is leaking air???

edit,,,ok returnissubwort sorry weak space bar here too tired tofix

Probably a stupid question, but when you say everything was rinsed and cleaned does that include the paint strainer bag?

trigger said:

Probably a stupid question, but when you say everything was rinsed and cleaned does that include the paint strainer bag?

Click to expand...

Yes. I boiled the paint strained bag I water for 10 mins before using it just in case there was any oily/plasticy stuff that would come off it. Because it wasn't sold as food grade I had reservations about using it.

wilserbrewer said:

your new whirlpool is aerating the wort would be my guess...your return should be below wort level,,,or perhaps your pump is leaking air???

edit,,,ok returnissubwort sorry weak space bar here too tired tofix

Click to expand...

The return is near the bottom of the kettle. Definitely below the wort level. However, I think you are right about the aeration. I recirced water in the kettle after installing the whirlpool return and didn't see any bubbling. Im going to run some tests to see what could've happened.