Infections

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Simon_W

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Hey everyone,

I think this might be my first ever post, I've been lurking in the background for years :)

I have been homebrewing for almost 10 years and have made many very nice brews but in recent times, despite knowing how important sanitisation is, I am managing to get infections. It is blowing my mind and keeping me awake at night sometimes!

I want to run a few things by you guys, to get your thoughts. First I'll go through my process from the boiler.

1. Hot wort is gravity drained to a plate chiller and then to the fermenter. I sterilise the pipes and fixings with Bruclean, I put the plate chiller in the oven, full with boiling water for 30 minutes at 140 degrees.

2. Ferment for 2-3 weeks without opening. Fermenter is Brewtech conical fermenter, airlock with starsan in it.

Note: At this point, the beer tastes great.

3. I boil up sugar and water and add a dose to each bottle. All equipment here sterilised with starsan.

4. Then bottle with a sterilised bottling wand. Bottles are already clean but sterilised with starsan. Also recently got a new wand and new silicone pipes.

5. Then I put on a sterilised cap.

After 3 weeks bottle conditioning, I start to get an unintended sour taste in some of my batches.

My thoughts:
If when I bottle the beer, it always tastes great, does this mean there is no infection introduced until bottling day?

Am I paranoid to think somehow wild yeast/bacteria is getting into the bottles from the air?

Is the strength of beer a factor? Maybe not enough data but the 4% beers seem more likely to get infected than the 5+% beers.

Thanks in advance for your thoughts and advise :)
 
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The-Engineer-That-Brews

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That must be heart-wrenching. Apologies if this seems like an obvious question, but what it that makes you sure it's a biological contamination issue?
 

phildo79

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Are you using glass or plastic bottles? Plastic bottles can degrade over time. I judged a comp in January and had a beer from a plastic that wasn't very good. The brewer noted the age of the bottle and sent me the same beer but in a new plastic. The difference was night and day. I'm not saying the first beer was infected but it was a far cry from how the beer should have tasted.
 

Simon_W

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That must be heart-wrenching. Apologies if this seems like an obvious question, but what it that makes you sure it's a biological contamination issue?
No problem, it is a fair question!
My suspicion of a biological contamination is the rapid deterioration of the flavour from point of bottling to 3 weeks in a bottle. For example a hoppy pale ale loses the hop flavours and the sour flavours develop. It produces a similar flavour to beers I made when I was less experienced and starting out brewing.
 

Simon_W

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Are you using glass or plastic bottles? Plastic bottles can degrade over time. I judged a comp in January and had a beer from a plastic that wasn't very good. The brewer noted the age of the bottle and sent me the same beer but in a new plastic. The difference was night and day. I'm not saying the first beer was infected but it was a far cry from how the beer should have tasted.
I use glass bottles these days but I did start out using plastic back in 2009 :D
I agree, they get a bit dodgy, much like plastic fermenters if they get scratched.
 

MickDundee

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No problem, it is a fair question!
My suspicion of a biological contamination is the rapid deterioration of the flavour from point of bottling to 3 weeks in a bottle. For example a hoppy pale ale loses the hop flavours and the sour flavours develop. It produces a similar flavour to beers I made when I was less experienced and starting out brewing.
A lot of off flavours develop over time rather than appearing straight away, oxidation for example, and might not necessarily be a result of wild yeast.

When you say “sour flavours” is there anything particular that comes to mind that might help us identify the issue? Also, is it only the flavour that is affected or does colour, mouthfeel, carbonation (gushers) change over time?
 
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darrellm

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Are you getting excess CO2, which is usually a sign of infection: foaming bottles or even bottle bombs? If not and it's just a flavour change, I'm with @MickDundee , I don't think that's an infection, sounds more like oxidation to me.
 

the baron

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Sounds like a possible Lactobacillus if it is getting a sour taste.
Are you AG brewing or Kit brewing?
 

The-Engineer-That-Brews

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No problem, it is a fair question!
My suspicion of a biological contamination is the rapid deterioration of the flavour from point of bottling to 3 weeks in a bottle. For example a hoppy pale ale loses the hop flavours and the sour flavours develop. It produces a similar flavour to beers I made when I was less experienced and starting out brewing.
I just thought it was worth asking, because it sounds like you're doing everything to control stray yeast/bacteria (far more than I do); so either (a) there is some incredibly powerful source of infection that's defeating your controls, or (b) the cause is something else... 🤷‍♂️
 

Dads_Ale

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You say you put boiling water in the plate chiller and put it in the oven but do you run any cleaner through it?
I am wondering if you have a crud build up in it over time.
 

the baron

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Plate chillers are notorious for holding crud even though you run loads of cleaning fluid/sterilisation fluid it will eventually get and hold crud.
If you strip it down I would be surprised if it was fully clean
 

Cwrw666

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I also would suspect the plate chiller. Try no-chill.
I occasionally strip down the tap on my boiler - despite always running boiling water through before use, followed by hot wort as it goes into the FV, followed by thorough rinsing out - it's amazing how much crud builds up inside it. I would think a plate chiller would be even worse.
BTW filling it with boiling water and cooking it at 140 - the water would actually prevent it getting above 100.
 

Dads_Ale

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I would also look at changing your cleaner. I am not familiar with Bruclean but it looks similar to VWP. I used to use VWP and found things just got browner over time. Tried some PBW and was amazed how much crud came off.
I now use Chemclean as it is cheaper for cleaning and Chemsan for sanitisation.
Possibly time for a thorough strip down of taps and fittings and a good soak in Chemckean.
 

The-Engineer-That-Brews

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BTW filling it with boiling water and cooking it at 140 - the water would actually prevent it getting above 100.
That's is true; however the water vapour (steam) created will get much hotter.
My understanding is that hot+damp is especially effective at sterilising tough customers like mould spores
 

phildo79

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Are you getting excess CO2, which is usually a sign of infection: foaming bottles or even bottle bombs? If not and it's just a flavour change, I'm with @MickDundee , I don't think that's an infection, sounds more like oxidation to me.
Do all infections cause excess co2? I have just made a gamma ray clone and it has been in the keg about a week. When I first kegged it, it tasted a bit green. It now has a strange synthetic taste. It is not overly gassy.

It is a flavour I have experienced before, when I did my first brew in a fermentasaurus. I put that down to not cleaning it properly before using it but my cleaning regime hasn't changed since I started brewing in a keg. I am left wondering if I haven't rinsed everything properly, have an infection or one of the hops I used just takes longer to mellow out.
 

Griff097

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Plate to plate heat exchanges can be thoroughly cleaned with brick acid, do wear gloves and eye protection though and keep your head away.
That's how we clean scaled up boiler plates.
 
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