I'm new to the hobby and recently made my first brew, I've used a simple plastic fermenter (25L) for primary, and after I finished the bottling process I washed the fermenter and waited for a couple of weeks before washing it again thoroughly.

By the time I got around to the second wash a bad odor has developed and hasn't disappear completely when I finished washing.

The beer from the first brew turned out ok, I don't think it's the source of the odor, It mighty have been the water from the first wash, I used a hose behind my house.

Can this odor contaminate my wort if I'll use the same fermenter again? Will it affect the quality of the brew?

And if so, is there any way to get rid of it without ruining the Fermenter?

6 Answers 6


What does the fermenter smell like? In my experience plastic fermenters have a tendency to pick up smells from prior fermentations and consistently smell like that, even when clean and empty. I've successfully fermented new batches in a fermenter that smelled like a prior batch but if it was a new smell I might have been a bit more concerned. It's certainly possible that microorganisms in the water you used to rinse out the fermenter were able to take a foothold and as a result cause that smell.

I would say give it another once over of cleaning and sanitizing but let it sit for a while with the sanitizer in it before you brew your next batch. That way if there's anything nasty and especially resilient in there you should kill it even if you don't get rid of the smell. Then try fermenting in it again and see how it turns out.

That said, plastic is somewhat known (albeit amongst the fairly paranoid homebrewing community) for harboring certain yeasts and bacteria in tiny scratches that can ruin subsequent fermentations. So if you're​ really concerned about potential contamination the best solution is to get a new fermenter and make sure you clean and sanitize it before and after each use.

But if the smell is reasonably close to what your last fermentation smelled like that's probably overkill. Try using it again and just make sure you a good job of cleaning and sanitizing everything that touches your wort post-boil.

  • 2
    "let it sit for a while with the sanitizer in" - but always read manual, some sanitizers are not safe for prolonged contact with some materials. Be sure if your particular one is safe with the kind of plastic your frmentors are made of!
    – Mołot
    Commented May 15, 2017 at 12:51

I have had a few 'smelly' plastic fermenters in my time, never has greatly impacted the beer coming out of them. If you are concerned then letting a bicarbonate of soda solution sit in them overnight then sanitising and drying before storage can help.

If it smells rotten or sulphurous, then I would fill it with bleach and let that sit overnight before a brew day, and rinse with a no-rinse sanitiser or boiling water to make sure you clean out the bleach. If it gives a bad brew after this treatment bin it and if you can afford it go stainless.


Does it come with a spigot? Those things have a tendency to be skipped while cleaning and sanitising. So, if you have one: take it off and soak it for a night in some sanitiser solution.


What also helps against smells is using (denatured) 100% ethanol. Rub the fermenter with some cotton drenched in it, then let it dry. Works every time at my side.


I find that odours can build up in a washed but then sealed container. I often use PBW on my plastic brew buckets and even though washed and sterilised the remains of the PBW can themselves provide nutrient for mold growth if not thoroughly rinsed out and then drained/dried. So it is usually best to scrub/rinse the buckets after use and then sterilise (eg with hot PBW/Starsan/whatever) before use. I mean rinse, store, sterilise, use. Of course its possible to sterilise before storage but then I recommend at least scalding the brew bin with boiling water to passivate any lurking microbes that may have returned during storage.


Bite the bullet and get a 7 gallon stainless fermenter. It only hurts once.

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