Fermzilla cleaning and white crust

[sounddoc]

Hi all,

I'm having trouble believing I'm the only one who's experiencing this. I've done about 10 brews over the last year in my Fermzilla and I love it. Last brew was infected from my mash tun valve (trust cleanliness, but verify...the last part is important) and I'm deep cleaning all my equipment. Something I've noticed on my Fermzilla's black plastic / rubber bits, particularly the butterfly valve, is some whitish crust after it dries. I use warm PBW solution to soak for an hour or so, then rinse and it shows up once it's dry. I'm able to scrub some of it off with a scotch-brite pad, but I don't want to damage it.

The picture says it all, although with the light here it looks a lot worse than it is. I've brewed all sort of ales and yeast, dry hopping, but nothing weird with adjuncts, etc...

Thanks for any insight. I believe the materials used is ABS plastic. Only cleaning chemicals to touch it have been PBW and Star-San. Our water is very hard and our appliances have some scaling (did I just answer my own question?) The only treatment I use are campden tablets. Ph in the mash is usually around 5.2. That's another story...

 

[VikeMan]

I don't have an answer about what's going on with your fermzilla plastic parts, but I'm curious about the infection on your last batch. I suspect it's not uncommon at all for bugs to get a foothold in a mash tun valve, but that shouldn't infect a batch of beer, assuming the wort was boiled.

 

[sounddoc]

Black sludge. I didn't rinse through enough on the last batch, and I figured that blasting with scalding water (brass fittings) would be good enough. I've been lucky over the years and got lazy as a result. I thought the same thing, 'eh, it'll boil'. Today I took apart my 2 piece ball valve too. yech!!!

To be technical, it wasn't infected, but some mold allowed the yeast to create off-flavors, i.e. phenols (bandaids)

On the upside, I have a great phenol-brau recipe. Too bad it's getting dumped.

 

[Elric]

That looks like textbook hard water scaling to me.

 

[VikeMan]

To be technical, it wasn't infected, but some mold allowed the yeast to create off-flavors, i.e. phenols (bandaids)

I'm not award of any mold either being able to survive a boil or somehow causing yeast to do anything unusual flavor-wise. Can you expound on this or provide a source for further reading?

 

[sounddoc]

https://beerandbrewing.com/off-flavor-phenolic/
Jump down to sanitation. Bacteria, i.e. slimy mold, will cause the yeast to produce off-flavors, in this case Band-Aids. My campden tablets can handle chlorine and dissolved bacteria, but not chunks hiding in hardware that made it's way into the wort.

 

[sounddoc]

That looks like textbook hard water scaling to me.

Yup, overnight soak in pbw got rid of most of it. Going to try vinegar next. I'm not worried as it's been around for a while, it's just getting more each cleaning.

 

[VikeMan]

https://beerandbrewing.com/off-flavor-phenolic/
Jump down to sanitation. Bacteria, i.e. slimy mold, will cause the yeast to produce off-flavors, in this case Band-Aids. My campden tablets can handle chlorine and dissolved bacteria, but not chunks hiding in hardware that made it's way into the wort.

Ok. But that reference doesn't say/mean what you think it does.

Slime Molds (or any kind of molds) are not bacteria. Some bacteria (and some wild yeast) can cause phenolic ("band-aid") off flavors. These bacteria (or wild yeast) don't cause your brewer's yeast to make phenolic compounds. Some brewer's yeast strains ("POF+" strains) do make phenols, but not because some other microbe influenced them in some way.