Persistent oxidised beer problem

[manticle]

I agree context is a very good thing.

 

[indica86]

I'd suggest you write Palmer a letter telling him he's wrong. Or maybe write your own book, have a brewing radio show, be famous in the home brew world for having a good idea about the subject....

Wow, that's a rather psychotic attack on a comment.

By oxidation when the wort is hot I assume we are referring to Hot Side Aeration? There is also some thought that this is a fallacy.
In my opinion the John Palmer online book is a very good guide but not all fact. There may have been updates I am unaware of in the paid for version.

That very same text you quoted claims dimethyl sulphur is produced from wort that is not readily cooled. It also claims that cold break does not occur without thermal shock aka rapid cooling of the wort.
Neither of these claims are correct, if they were no-chill as a homebrew method would not work, at all.
I have made clear clean lagers using a no chill with only kettle finings.

 

[barls]

By oxidation when the wort is hot I assume we are referring to Hot Side Aeration? There is also some thought that this is a fallacy.
In my opinion the John Palmer online book is a very good guide but not all fact. There may have been updates I am unaware of in the paid for version.

it might also be worth pointing out the free online version is v1 i believe he is up to 5 or so which has been revised since he first put out the book.
my personal copy is on loan atm but I'm sure its v3

 

[Jack of all biers]

Hot side aeration is not a fallacy. It may not be as important a creator of staling factors as are other factors, such as fermentation or post fermentation practices, but if you allow unnecessary oxidation at the 'hot side' stages you are increasing the chances of oxidation flavours or staling in your finished beer. Even Dr Bamforth in his 2009 interview with Palmer on 'Brew Strong' agrees 'hot side aeration' exists and that it is commonsense to reduce oxygen exposure to hot wort, he just stresses that more important is the post fermenation handling of the brew. He even states that keeping the brew cold exponentially increases it's shelf life and slows the chemical processes that break down the oxidised compounds. This does suggest that if there are more oxidised compounds to begin with then this process will create the small amounts of staling compounds such as Trans-2-Noneal aldehyde quicker leading to a shorter shelf life before the beer stales.

Now given that many on this forum take great care to ensure good yeast pitch rates and good fermentation and post fermentation handling of the packaged brews, they can easily get away with the minimal amounts of oxidation that occur by using the 'no chill' method. However there may be others who don't. Suggesting that it doesn't exist may lead people to ignore or dismiss something that is causing them a problem. Especially those who can lengthen the shelf life of their beers by cutting out poor practices of splashing and pouring hot wort when transfering from kettle to cube. It is so easily and cheaply over come.

Go to http://londonamateurbrewers.co.uk/2013/06/hot-side-aeration/ for just about the only referenced available-for-homebrewers paper (2010) on the topic.

Below is a 2010 forum entry from the author of that presentation paper, Dave Wilton found at this site: http://www.jimsbeerkit.co.uk/forum/viewtopic.php?f=2&t=36777&hilit=hot+side+aeration

Re: Hot Side Aeration
by dave.wilton » Wed Oct 20, 2010 7:18 am

"I did a lot of reading about Hot Side Aeration for a presentation at London Amateur brewers. I found was that there is very little scientific information available to the homebrewer about this, most of the discussion is still held in the journals. The forums contain a lot of hearsay with nobody actually supporting views.

The main impression I got was that the science behind the issue is sound, so it can have an affect. However, it is a very complex issue with many other factors affecting beer stability as well. The most interesting 'article' I found (which really supports this view) is an interview with "Dr. Charles Bamforth on hot side aeration with Jamil and John Palmer". http://www.thebrewingnetwork.com/shows/475.

The best tip I came across was that aeration is far more of a problem in secondary / bottling so if you are worried start at the end of your brew and work backwards. Most things to put in place are easy and cheap, such as a pipe from mash tun to boiler, so I just do them anyway"

Edit - grammar and website link corrections

 

[Jack of all biers]

That very same text you quoted claims dimethyl sulphur is produced from wort that is not readily cooled. It also claims that cold break does not occur without thermal shock aka rapid cooling of the wort.
Neither of these claims are correct, if they were no-chill as a homebrew method would not work, at all.
I have made clear clean lagers using a no chill with only kettle finings.

If it is your own anecdotal evidence you are relying on for these statements, it may have something to do with the malted grain you are using being of high quality or using long boils to evaporate off a high percentage of DMS amongst many other factors that reduce DMS in wort. Palmer is not the only researched source that claims Dimethyl Sulphide is caused at high temps post boil. Just a quick internet search would have located this site amongst others that state the same thing. http://beersmith.com/blog/2012/04/10/dimethyl-sulfides-dms-in-home-brewed-beer/ which states amongst other many interesting facts about DMS

"Rapidly cooling your wort after boiling is also important. The SMM to DMS conversion continues at temperatures well below boiling, so DMS is produced even while the wort is cooling after the boil. However, unlike the mash, DMS produced while cooling cannot be boiled off. This conversion continues even if the hot wort is vented. For every hour you have hot wort sitting around, you will produce approximately a 30% increase in DMS."

Just because anecdotal evidence gives you the impression that one thing is possible doesn't mean others are wrong. It might mean through blind luck you've gotten away with it. Like all things luck, it doesn't always last.

Regarding cold break with some more on DMS, http://byo.com/hops/item/499-cooling-hot-wort-homebrew-science.

They all can't be wrong.

 

[manticle]

DMS will continue to be produced while the wort sits above a certain temp but modern malts with an appropriate boil will not contain enough to be detected by most palates in a no chill situation (homebrew level which is the only level where no chill is a practical method).
It does go way beyond luck or just indica's personal experience.

No chill, done properly does not result in discernible levels of dms, any more than chilled wort does.
Straying off topic.

 

[Seeker]

Update: latest beer is also affected even with all precautions followed.

The one thing still common to all affected beers is the blue bunnings cans . All affected beers have been no chilled and fermented in blue drums or cans, so that's the next thing to eliminate.

I'll also test them with boling water to see if I get any taste come through.

 

[kaiserben]

The one thing still common to all affected beers is the blue bunnings cans . All affected beers have been no chilled and fermented in blue drums or cans, so that's the next thing to eliminate.

I'll also test them with boling water to see if I get any taste come through.

I used to no-chill in those (specifically the blue "BMW" 10L jerry cans from Bunnings).

The blue colouring on the cans faded fast. Most of the batches no-chilled in them also faded fast.

I haven't had any issues with them since (when putting chilled wort into them).

 

[Seeker]

Gutted to report problem persists in current beer. I've now tipped away 4 or 5 beers and not had a successful AG since September!


I brewed one full mash apa, and one kits & bits apa.

Full mash beer has the same off flavour 4 days after kegging.
Kit beer is fine.

So, things all affected beers now have in common that ok beers do not;

• All bad beer has been in the same keg - every beer I've had in this keg has been affected. Bought cheap as HBS return & apparently used once - 25litre.
• Silicone kettle transfer hose - seems unlikely but was bought same time as the keg.
• All affected beer has used the same batch of MO, kept pre-cracked in vacuum bags, from a HBS I've never used before (hops I got were not good)
• All affected beers full mash and no chilled.
• Water additions; calcium sulphate, ph buffer, epsom salt.

Non affected beers;

• FWK or kits & bits
• Known good 19l corny
• used same fermenters, temps, fridge, kettle, and crystal.
• Same water.
• same care taken.
• not no chilled

Additionally I fed some of the affected beers wort to some stored yeast - just tried that and could detect the off flavour. Also no hop flavour either as not no chilled or cube hopped.

My best guess now is that the keg has been abused internally and may be contributing iron oxide through pits or scratches. No idea how likely that is, but it would fit some of the evidence, mainly;

• Beer seems ok before kegging (not 100% on that one)
• Flavour gets worse as time goes on.
• Last wort seems ok as stored yeast beer was ok.
• Other keg has never had the issue, same gas, lines and tap.

 

[manticle]

Seems obvious to me that if there are variables in common, they should be eliminated.
Have you brewed any non-affected beer with that maris?
My money is on the keg.

 

[mxd]

certainly sounds like the keg, have you bottled any out of the fermenter at the same time as kegging ? That may assist in pointing to the keg.

 

[Seeker]

All the MO was affected, but the yeast stored beer seemed OK, and all went in same keg. Unfortunately I didn't bottle any, as I bought the 25l so I wouldn't have to.

I'm going to put the beer into a no chill cube and try to reproduce the fault with plain water.

 

[Seeker]

Well I stripped the keg and left it full of water. Tasted it and no noticable tang.

I sniff tested each bit - the main keg smelt slightly metallic with a rubber hint, probably just the top seal I guess.

BUT the poppets and posts absolutely reeked of steel! I was really surprised - it was very strong. I just put them in a glass of filtered water and drank and the last mouthful was horrible.

I'm cautiously hopeful that this is the problem.

When I bough the keg I rinsed in bleach, then rinsed well with water. I'm thinking the bleach took the film off the poppets and they need passivating again. I'm soaking in Star San then I'll repeat the test.

 

[Seeker]

I soaked the bits in strong star san solution for a few hours then left top dry an hour or so, but I just soaked in water again and the taste is very metallic still. Maybe the steel is just crap.

 

[paulyman]

For the price, new poppets, seals and posts? Definitely sounds like you have zeroed in on the problem. I'm sure I'm not the only one crossing fingers for you.