Beer contamination

[Asimi]

Dear all, sorry for the (potential) old problem topic, but I'm desperately looking for the advice to the scale:

Already several months I cannot make any brew batch as my beer is getting contaminated, namely, it becomes absolutely sour (no, I didn't brew sour at all). In the beginning, I got a sour taste within 1 or 2 weeks after brew day, after several exhaustive cleaning actions it seemed to improve, but I still got sour beers few weeks after bottling...

What I have done so far:
1. Made my cold side of Brewtools setup as simple as possible (4 valve setup with a single counterflow chiller directly to the primary fermentor)
2. Extensive cleaning after each brew day or transferring to the secondary or bottling:
a. 2 hour CIP with warm water + PBW
b. 2+ hours all separate parts (tri clamps, valves, etc) are sunk in PBW
c. All separate parts rinsed with StarSan
d. CIP rinsing met StarSan (1+ hour)
In the beginning, light beers have been contaminated in the primary fermentor within 1 or 2 weeks (then I can see that fermentation doesn't stop and the beer becomes sourer and sourer). What heavier beers are contaminated after transferring to the secondary fermentor...
After a couple of additional cleaning actions, it seemed the beer remains longer OK, but unfortunately becomes sour after several weeks in the bottles.
Has anyone got similar problems? How to solve them? Any ideas on how to recognize what kind of contamination it is?
Thanks for your suggestions,

 

[Craigerrr]

The one time I had a beer go horribly sour the taste was there before bottling. It was horrible, took a day to get the taste out of my mouth. I did not bottle it.
To my knowledge the only way for a batch to get an infection, is for it to be exposed to something. I have stayed away from counterflow chillers because I don't feel that I can clean them properly. It seems that something somewhere is harboring a nasty and infecting your brews.
Others may have other helpful opinions, but it does point to a cleaning, and or, sanitation issue.

 

[Over The Cliff Brewing]

What about your primary fermenter? Do clean and sanitize everything related to your ferm vessel? If its not the bottles, and not your kettle, I would look at the fermentation bucket or whatever you use.

 

[Minbari]

If it tastes sour before you bottle it won't get better. You have to fix the issue.

What kind of fermenter are you using?
Any valves in the fermenter?
I assume you are using an airlock with sanitizer in it.
How are you cleaning/ sanitizing bottles?
Sanitized bottle caps?

Pbw does a good job of cleaning and dissolving food matter but this is NOT a sanitizer. Soaking in it does very little IMHO.

I would soak everything you have in iodofor for a few hours. Take apart valves and make they are clean. Take apart quick connects and replace tubing that looks suspect. Even threaded ports can get contamination you can't see.

I had one batch do what you said. Soured and had green slime in it. Major clean and disinfect was the key. Also NOTHING touches the beer, post boil, that hasn't had a minute in starsan. Make sure your starsan is good too. Ph meter should read less than 3

 

[Asimi]

...I would soak everything you have in iodofor for a few hours....​

Do you have a commercial name for that? I will try to find the analogs.

I'm using SS brew tech unitanks.

 

[Donoroto]

Iodophor.
StarSan does not kill yeasts, and this is most surely the problem. Short if buying new equipment, you must use a stronger sanitizer. Iodophor is an iodine-based solution. It does not need rinsing, but must be allowed to drip and air dry.

Use it for all your cold-side equipment, particularly the fermenter and valves. The counterflow chiller can be sterilized with boiling water run through it with no chilling water. A few seconds is enough but 10 minutes costs little more and guarantees results.

Take anything you can apart for cleaning and sanitizing.

I wrote a thread 'an almost newbie's thoughts on cleaning snd sanitizing' which might help https://www.brewersfriend.com/forum...es-thoughts-on-cleaning-and-sanitation.14019/

 

[Minbari]

...I would soak everything you have in iodofor for a few hours....​

Do you have a commercial name for that? I will try to find the analogs.

I'm using SS brew tech unitanks.

It is made by 5 star, same as star stan. It is actually called iodofor.

Ok. So quite a few ports and valves. I would take them all off, apart and clean em.

 

[Mark Farrall]

I wouldn't start with the brew system, it could be involved, but there's much more likely candidates. Regardless of your cleaning regimen, it's highly likely that at the end of the boil you have a bug free wort. So the bugs are being introduced after the boil. Could you go into how you transfer to your fermenter and what you do to prepare your fermenter. Also how you handle/prepare your yeast. Then the same sort of description for bottling side of things.

Can you describe the sour taste? It might give some indication of the type of souring microbe.

 

[Mark Farrall]

Iodophor.
StarSan does not kill yeasts, and this is most surely the problem....

StarSan is an acid solution. Acid solutions have been proven to kill yeast. What we don't have is how long you need to use StarSan for the various microbes and the countless strains of each. I can see why 5Star haven't bothered to put this information through the regulatory process so that they could publish it as they have Iodophor squarely aimed at this scenario and they see StarSan as a quick, final rinse before use product.

Based on other experiments I'd guess that StarSan has killed the overwhelming majority of brewers yeast strains within a minute or so. There will, of course, be a few hardier strains, like some Brett. and some Sacch. Cerevisiae diastaticus strains that will take longer. So long that it may not be practical. The same will be true for the other microbes. Most lactobacillus die very easily in acid, but there'll be others that are harder to kill (I think Lactobacillus Brevis is particularly hardy).

Sorry for the pedantry, as ultimately, yes, use iodophor if you're looking for a sanitiser based solution to killing a wide range of microbes as there's published data showing how to use it in this scenario, while there's nothing out there for StarSan.

 

[Asimi]

I wouldn't start with the brew system, it could be involved, but there's much more likely candidates. Regardless of your cleaning regimen, it's highly likely that at the end of the boil you have a bug free wort. So the bugs are being introduced after the boil. Could you go into how you transfer to your fermenter and what you do to prepare your fermenter. Also how you handle/prepare your yeast. Then the same sort of description for bottling side of things.

Can you describe the sour taste? It might give some indication of the type of souring microbe.

Correct, I also suspect transfer equipment + coldside (primary fermenter). I'm using a counterflow chiller (parallel plate chiller has been removed the first from the system, but it didn't help :-( ).
Through the valve setup I can circulate hot wort through the counterflow chiller during boiling and only what remains on the cold part is the silicon tube to the fermentor.
I removed the oxidization stone and oxidize wort by splashing (not the best but I wanted to simplify the system as much as possible).
silicon tube is sanitized by Star San + the whole fermentor is sanitized by star san + additional alcohol sanitization just before use.

The taste becomes sour acetic, a lot of small bubbles and the foam retention is almost nihil. Tastes and smells a bit like an apple cider.
I have a suspicion that it becomes stronger when aerated a bit (at bottling)
Couldn't find anything strange on the surface of the beer

 

[Asimi]

StarSan is an acid solution. Acid solutions have been proven to kill yeast. What we don't have is how long you need to use StarSan for the various microbes and the countless strains of each. I can see why 5Star haven't bothered to put this information through the regulatory process so that they could publish it as they have Iodophor squarely aimed at this scenario and they see StarSan as a quick, final rinse before use product.

Based on other experiments I'd guess that StarSan has killed the overwhelming majority of brewers yeast strains within a minute or so. There will, of course, be a few hardier strains, like some Brett. and some Sacch. Cerevisiae diastaticus strains that will take longer. So long that it may not be practical. The same will be true for the other microbes. Most lactobacillus die very easily in acid, but there'll be others that are harder to kill (I think Lactobacillus Brevis is particularly hardy).

Sorry for the pedantry, as ultimately, yes, use iodophor if you're looking for a sanitiser based solution to killing a wide range of microbes as there's published data showing how to use it in this scenario, while there's nothing out there for StarSan.

Couldn't find iodophor in the Netherlands, so have chosen peroxyacetic acid. Hopefully, it will do the job as well

 

[Minbari]

Couldn't find iodophor in the Netherlands, so have chosen peroxyacetic acid. Hopefully, it will do the job as well

You can make it too. Just buy medical iodine and dilute it. Just make sure you rinse. Iodine beer would not be good

 

[Sunfire96]

You can make it too. Just buy medical iodine and dilute it. Just make sure you rinse. Iodine beer would not be good

Why would you rinse your sanitizer, won't that increase the risk of recontaminating? Sanitizer should be the last thing a surface touches before wort/beer is added

 

[Minbari]

Why would you rinse your sanitizer, won't that increase the risk of recontaminating? Sanitizer should be the last thing a surface touches before wort/beer is added

If I rinse, i do it with star stan. I just don't trust the "no rinse" of iodine

 

[Donoroto]

I've 'not rinsed' the Iodophor to no ill effect. The film left behind is very thin, and once the water is gone there's not a heck of a lot of iodine left. But I don't see a problem with rinsing after sanitizing, as long as it gets sanitized again before you use it, because the rinse is contaminating it.

However, using an iodine rinse by following the manufacturer's instructions, letting it drip and air dry, and THEN washing and StarSan-ing it would be just fine. No chance of iodine (or whatever). But whatever you do use needs to be really really effective, eh?

I think everyone agrees @Asimi (well, his equipment) has some kind of rogue yeast infection, so once it is really and truly killed - you can't really go overboard here - then washing and sanitizing can proceed along the lines of what most of us do as standard procedure.

 

[WesBrew]

-i've used nothing but iodopher the last 10 years. fermenter, bungs, airlocks, tubing, aerator stone...etc sanitized.
-I do not use sanitizer on the pump, plate chiller or kettle. After a boil is done, i boil up some plain water and pump that through the chiller to clean it out. At the end of each boil i'll run the boiling wort through the pump and chiller, back into the kettle for a few minutes to sanitize everthing.
-Once a year i'll make a sink tub full of water/bleach and put all of the tubing, airlocks etc in there for a multiday soak to clean crud off
-lastly, for every brewday i make a tub of sanitizer for dipping my hands in repeatedly. You can use a small bucket too.
*as Donorato said, you've got a rogue yeast lurking somewhere. old plastic fermenters? scratches? inside of tubing?

 

[Asimi]

-i've used nothing but iodopher the last 10 years. fermenter, bungs, airlocks, tubing, aerator stone...etc sanitized.
-I do not use sanitizer on the pump, plate chiller or kettle. After a boil is done, i boil up some plain water and pump that through the chiller to clean it out. At the end of each boil i'll run the boiling wort through the pump and chiller, back into the kettle for a few minutes to sanitize everthing.
-Once a year i'll make a sink tub full of water/bleach and put all of the tubing, airlocks etc in there for a multiday soak to clean crud off
-lastly, for every brewday i make a tub of sanitizer for dipping my hands in repeatedly. You can use a small bucket too.
*as Donorato said, you've got a rogue yeast lurking somewhere. old plastic fermenters? scratches? inside of tubing?

From plastic parts I only use silicone gaskets for tri-clamps and silicon hose (relatively new). The rest is either on the hot side or removed from the setup (like aeration stone/connection)

 

[WesBrew]

From plastic parts I only use silicone gaskets for tri-clamps and silicon hose (relatively new). The rest is either on the hot side or removed from the setup (like aeration stone/connection)

there is definitely a yeast hanging out somewhere. try also if you havent, removing any teflon tape from fittings. sanitize and retape, separate and sanitize any seals.
It might just be something resistant to the type of sanitizer you used. i would definitely try iodine

 

[Asimi]

No Teflon tape, no threaded connections
It looks like quite resistant yes... I will try tomorrow to soak everything into peracetic acid after thorough PBW cleaning (again...)

 

[WesBrew]

It might be worth an email to SS. Maybe they could give some advice or indicate where a likely hiding place might be in your eqipment.

-less likely but do you know the ph of your mash? any chance an acidulated malt got mixed up in ingredients or too much acid used?