• Welcome to the new forum! We upgraded our forum software with a host of new boards, capabilities and features. It is also more secure.
    Jump in and join the conversation! You can learn more about the upgrade and new features here.

Used conical fermenter

Dhm8484

Apprentice
Joined
Oct 25, 2016
Messages
9
Reaction score
0
Hello I bought a used conical fermenter (7 gal) from a buddy and its a stout brand.  I noticed what seems to be small chips or pits no bigger than pen tip, that where starting to rust.  I used a scotch brite pad with soap and water and it took rust off but still have the small pits.  Will this effect my beer?  I use star san for sanitizing so I thick if I scrub and sanitize good it should be fine.  Let me know what everyone thinks.
 
Depending on how much surface area is being exposed to rust you could end up with a metallic flavour in your beer
 
This was just posted recently about metallic off flavours http://beersmith.com/blog/2016/10/14/metallic-flavors-in-beer-off-flavors-in-homebrewing/
 
Okay well I guess the only thing to do is try it I guess, and also is it safe to use oxyclean to clean or should I buy pbw cleaner
 
Plus he said he has used this for last 5 years and he noticed some rusting within the last year and he has won some local brewing competitions using this fermenter
 
Firstly if it's not stainless then I personally wouldn't use it.  Secondly, if it's only 296/306 stainless then it's likely to have a small amount of rusting at acidic pH due to being a lower grade of stainless.  If it's 316 then this is food grade and quite good as a fermenter.  Regarding sanitising, a good bath with boiling water certainly is a test of time.  I prefer this before putting down any fermentation. 
Best Regards,
MBF...
 
Yea it's stainless, the brand is Stout, based out of Oregon.  It's Chinese made the ball valves have the writing lol, not sure of the grade unless it says somewhere on it. http://conical-fermenter.com/7.3-Gallon-Fermenter.html, this is the link.
 
What the fermenter needs is passivation.

I fear the pits you see may have come from using chlorine or chlorinated bleach on the stainless. In commercial breweries chlorine is sometimes added to caustic soda for cleaning, but the pH must be > 10 pH to prevent pitting. The rust stains are from where the chromium has been reduced and the surface hasn't reoxidized. Luckily, this is an easy thing to reverse.

What you want to do is circulate a 20% solution of Nitric Acid for 30 to 45 minutes at 120o to 140o F. Then you just let it air dry. The surface will passivate as it dries. After that, you can clean and sanitize it for use. If you can't recirculate it with a pump and sprayball, a simple soak will do.

Do not use more steel wool on the surface of the metal. This strips the patina and promotes rust. If you must use an abrasive, use a non metallic type of scrubby. 
 
Yea I read about doing that and someone said to use bar keeper friend will do the same affect
 
Dhm8484 said:
Yea I read about doing that and someone said to use bar keeper friend will do the same affect

Probably not. Barkeeper's friend is Oxalic acid. That's a reducing agent, which is fine for removing an oxidation, but not creating it. In other words, it's great for removing rust (oxidation) but is less effective at restoring the patina.

The passivation chemistry needs to deliver oxygen to the metal, not take from it. Used correctly, Barkeepers Friend isn't strong enough to remove the patina from stainless. It is great at removing stains that are on top of the patina.
 
What if I'm not comfortable using the acid.  Is there anything else that can be used? 
 
Dhm8484 said:
What if I'm not comfortable using the acid.  Is there anything else that can be used?

I understand your concern. We're talking about chemicals common in the brewing industry.

Homebrew shops often sell it as Star San Acid Cleaner #5, but there are other manufacturers. Proper handling is just basic food service gloves and safety goggles. Once diluted into water, it's safe and easy to use.
 
Okay thanks then my local brew shop probably has it then, do I just scrub it or let it soak
 
You can just let it soak for an hour or so. It's better and more economical if you can recirculate it, instead of making a large batch of it. But, soaking will get the job done.
 
Back
Top