Diacetyl Problems

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I regularly knock up a batch of GMK's Aust draught using a kit, light malt, SafAle yeast and dry hopping with some Hallertau. The hops tend to make it a bit floral/spicy but I really like that. I ferment in primary for about a week and then rack into sec' for about 10 days. The only slight change this time was that I added about 250g of liquid wheat malt to give it just a bit more mouthfeel.

I've just tried the first taste of one I kegged a couple of weeks ago and I've finally discovered what the books talk about when they descibe Diacetyl as being 'buttery'. Bloody hell it's crook.

It's not a flavour I enjoy really even though I know that in some styles like Brown Ale a hint of this flavour is considered desirable - but wow have I overdone it and I wasn't even trying :( .

Looking though some texts (Palmer in part') I am led to believe that this can occur either due to an infection (pediosomethingorother) or too long a lag time. I've looked up my brewing notes and see that it only had a lag time of about 6 hours before bubbling become evident so I'm guessing that that wasn't the problem.

If it's an infection then I'm going to have to revise my already neurotic sanitation techniques but I wondering it there's anything else that may have caused it that some of you may have encountered?

Was it the Wheat Malt - I don't think so as I've added small amounts to a number of brews without this effect.

One thing that did come to me was that perhaps it fermented a bit too warm at the start of the primary and then a bit too cool for the rest of the time. If this is the cause is it too late to perhaps try a Diacetly rest by standing the keg in a warm spot for a few days.

Or does anybody want some liquid butter for their toast :blink:

trev i feel for you.
it happened to me also twice.
it sounds like yours, like mine was a result of infection because it was a nice neutral yeast fermented at the right temp and left for a reasonable time in contact with the beer after it had fermented out.so any diacetyl should have been reduced back to higher alc.
with mine it tasted great untill i kegged a fridged it.so you would think if it was from the yeast you would notice it when you took the f.g.then it should get better within a couple days.

it doesn't really sound like this was the cause of the buttury pop corn flavour in these instances because the fermention and racking was spot on.

it would be good to get a little more info.
after fermention has been completed at the correct temp than left for a couple of days then should there be no diacetyl flavour?
if then the diacetyl seems to get worse would you presume an infection?
if so you would think a infection would only get worse and there would be no way of removing the diacetyl flavours that it produces.

my two were drinkable but the kegs lasted alot longer than any good beer.
both mine were dry hopped with northern brewer pellets straight to the fermentor.so i have at the moment just put it down to bad dry hopping practice.
diffintly get were that guy is talking about pop corn.
that microwave popcorn packet you get with butter in it is exactly the flavour i got.

I'm leaving it out of the fridge for a few more days. On the weekend I'll chill it down and try again.

I see your point about the infection - if it's noticeably worse when I try it again then infection is indeed the likely cause.

If I try it and it's no better then it's going straight down the sink!


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