Recurring infection...

Subliminalfringe · Joined: 31 Aug 2016 Posts: 14

Hello,

I put together a brewery about 2 years ago and it's been great. A few months in I started noticing a phenolic flavor that kept showing up in my beers. I tracked down the problem - something was growing on the impellers of the wort pump. I assumed that when I was first using the brewery I didn't really have a good cleanup process and I likely was negligent at some point. So I baked all the hoses and the CFC in the oven at 275 for an hour. I took the pump housing and impellers and cooked them for an hour in the pressure cooker (surgical sterilization). It worked and I was off happily brewing again. The clean up process that I put in place is as follows: I heat about 12 gallons of water that I recapture during cooling the wort to 180 degrees F while I am cleaning the boil kettle. Then I run the water through the wort pump->CFC->down the drain until the water runs clear. Then I recapture the clear hot water and use it to soak everything that I used for the day in Oxyclean. I use the vacuum to blow water out of the pump and CFC. On the next brew day I run boiling wort through the wort pump and CFC and back to the boil kettle during the last 10 minutes of the boil and get up to over 200 degrees coming out of the CFC. I have been thorough about sticking to this process and the infection has returned. Found some nasty smelling biofilm on the impellers of the wort pump again. So I appear to have a rather resilient house bug. I am hoping to benefit from everyone's experience to help me come up with an effective workflow to eradicate this.

Thanks,

S

**kal** · Posted: Sun Dec 09, 2018 5:32 am Post subject: Re: Recurring infection...

Subliminalfringe · Joined: 31 Aug 2016 Posts: 14

Hi Kal, thanks for responding,

My process on the cold side hasn't changed over the last 8 years and is pretty solid. Never had an infection when I was BIAB with my 7 gallon kettle.

Then I entered some beers at a competition and the judges picked up the phenolic fault. I have since completed a BJCP class and am very familiar with the flavor that my bug produces. The class has provided me a deeper understanding of where faults occur in the process.

In discussing my issue with the more experienced and knowledgeable members of the home-brew club, the consensus was that the issue was on the hot side. On the first time around with the infection I found some black colored snot on the impeller of the wort pump. Once I sterilized the CFC, hoses, pump everything was great for about 9 months. Last week I tapped a keg for the work holiday party and my first taste revealed my friend was back. I went straight to the pump and there was a biofilm on the impellers again and the inside of the pump housing smelled moldy. I again sterilized everything last week but haven't brewed anything yet. Hoping to find a way to prevent reinfection.

The final gravities are where they are supposed to be. This bug seems to slowly produce its flavor as the kegs lager. The more time that passes the stronger it gets.

Thank you,

S

mvakoc · Joined: 19 Sep 2011 Posts: 152 Location: Evergreen, CO

I can't really comment about your exact issues but thought I would mention my brew day process, which is slightly different than Kal's.

After the HLT is completely exhausted during the sparge, I fill it with ~ 5 gallons of fresh water. I heat it to 185. During this time the sparge is continuing and ends when I reach my target volume.

Once the HLT is up to temp and the sparge is done, I flush water through the hose that was attached to the MLT to get the obvious wort out. I use my favorite mod from Kal's design for this -- effectively two hose connects connected to a valved hot water and cold water supply. See picture #1.

I then hook that hose up to my second favorite mod -- a diverter for the HLT (picture #2). Using this I flush 185 water through the hose -> mash pump -> hose -> counterflow chiller -> hose to fermenters -> back into the HLT. I run this for 10-15 minutes. Note: I have a 25' silicone hose to go from chiller to the fermenters due to my brewery layout.

I leave the long hose end in the HLT very hot water for the duration of the boil to preserve sanitation.

At this point everything I will hook up to the boil kettle is both quite clean and sufficiently sanitized.

Post brew and fermener transfer, I cycle ~140 degree PBW through the same hose layout for 20 minutes or so, then rinse out (with mod #1).

Hope that makes sense. I haven't had any issues with nasty bugs and when I take apart my pumps occasionally to replace the thrust washers they are very clean, at least in appearance.

**kal** · Posted: Sun Dec 09, 2018 10:47 pm Post subject:

CHB · Joined: 17 Nov 2016 Posts: 7

I was experiencing the same issue … my beer was developing an aspirin-like taste -- kind of band aid like. I reexamined every aspect of my hot side and realized I wasn't cleaning my plate chiller as well as I should, and I addressed other aspects of my process. The whole exercise was good to go through and I brew better beer for it. But alas, my next beer was the same. The beer tasted "pretty good" when I was kegging it, but I was hopeful. 2 weeks later, it was not great, and 4 weeks, yuk!

Finally I figured it out. I think Kal is right ... the hot side has the advantage of being hot! So if you've got something bad going on there, it will likely be killed or mitigated merely by the heat. I'm almost embarrassed to admit what my issue was, but it was the cleaning on the cold side. I too am using Oxi. I've since resolved my issue and my beer is back to tasting fantastic. The issue for me was twofold. I was using too much Oxi in in my liquid (several scoops for 5 gallons). But the ultimate issue was that I didn't use hot enough water in the rinse. It was just that simple. I believe I was leaving Oxi residue -- as you know it's slippery and clingy -- and I believe some was still in the kegs and in my fermenters due to not hot enough complete rinses.

Sometimes my beer tasted great when I was kegging, or other times it was just “ok” when I was kegging. But after kegging, it would develop the taste. It’s almost a head-slap duh thing – very simple, but very important.

Good luck!

**kal** · Posted: Thu Jan 17, 2019 10:20 pm Post subject:

Glad you figured it out CHB!

Kal

dp Brewing Company · Posted: Fri Jan 18, 2019 2:17 pm Post subject:

Off the subject but one thing I was thinking about recently was the sight glass. The wort doesn't get hot enough to boil in the sight glass so should we concerned with contamination?

**kal** · Posted: Fri Jan 18, 2019 3:00 pm Post subject:

Pippicidal · Joined: 07 Jan 2019 Posts: 6 Location: Baja Sur

Here's some total noob input =) Are you pitching enough yeast Subliminal?

Following.