Smell remains after cleaning steel fermenter

[JeffersonCoastal]

I do a fairly thorough clean of my steel fermenter after fermentation. Scrub it out, soak in hot PBW, rinse in hot water, sanitize with StarSan. Looks good and smells good.
Then I put it away (in a clean, dry pantry closet). After x weeks, I will take it out for brew day. When I pop the lid and smell, typically a sour beer smell. So I always do the same cleaning process on an already clean fermenter the same day of brew day.

I've never had infected batches, nor off flavors in my beers, as I'm fairly consistently able to turn out good to excellent batches.

My question is - Is that smell normal? Should I replace the lid gasket? At this point doesn't seem to affect the final product, it just bugs me.

 

[BAF]

Can you remove the gaskets and soak those in PBW? In my experience, that's going to be what holds onto the smells.

I bet if you sniff the gasket specifically, you'll notice the smell is the strongest there.

 

[mattd2]

Do you have any valves on your fermenter? And if you do what sort are they?

If you have ball valves you need to flush these during your cleaning to clear out any beer, etc. that can get trapped in the cavity. Usually this includes opening and closing the valve will cleaner is flowing through it. And then again with water to flush the cleaner out of the valve.

 

[Steverus07]

Is it possible you’re smelling the (to me) unpleasant odor of the star san you left behind in the fermenter? I don’t know Phosphoric acid has a smell as it breaks down but I don’t love the smell of my bottles, growlers, and fermenters when I’ve left a little behind.

Still… it doesn’t hurt anything. Maybe test run a beer with out your extra “day of re-cleaning” and see if the beer comes out ok.

 

[hottpeper13]

How long between brews? I store mine with a folded paper towel between the pot and lid just like my cast iron dutch ovens.
If i forget and don't brew for 2 weeks it has a smell,kinda sour. I've not cleaned before using and my beers turn out good to excellent.

 

[JeffersonCoastal]

How long between brews? I store mine with a folded paper towel between the pot and lid just like my cast iron dutch ovens.
If i forget and don't brew for 2 weeks it has a smell,kinda sour. I've not cleaned before using and my beers turn out good to excellent.

Typically anywhere from 1-8 weeks (since I have 2 steel fermenters). So you take a dry paper towel, fold it, then clamp down the lid of fermenter?

 

[hottpeper13]

No clamp ,just rest the lid on top.