weird smell

[andyCo]

Hi folks
Was wondering if anybodys ever had a wired kinda of sickly smell before from some pre boiled wort ?
Thought I had a day to brew yesterday, mashed and then mashed out and just before I was about to boil on dinner got in the way, then company turned and so on ..
I pulled the grains out and left the wort sealed in the thermopot boiler over night.
When I opend it up this moring there was a sickly sweet almost like vomit smell and what like hot break on the top of the wort.
When it was coming up to boil there was lots of hot break, more than I'd seen before.
All boiled up and in the fv now , sample tasted fine but I can still smell it in the shed.
Not sure if the grain bill has anything to do with it ?
4kg pale
500g wheat malt
200g wheat
200g munich
200g oats


Andy

[DeadFall]

I was distracted during clean up and left a bin bag full of spent malt in my mash tun overnight. In the morning it had a strong smell, like sweet, spicy and rancid vomit; nearly threw up from it. The bag was very warm too. I always make sure I get the spent mash in the bin as soon as I can now.

[Charles1968]

When you say pre boiled wort, do you mean unboiled? Unfortunately, wort doesn't keep if you haven't boiled it. As soon as the temp falls under 50 or so, bacteria start multiplying and will sour it. You've now killed the bacteria by boiling, but it's likely they've created off flavours that will spoil the beer. If your sample tasted ok, perhaps you should let it ferment out and keep your fingers crossed. Personally, I would start again - good excuse for another brew day.

[andyCo]

Deadfull, it was just wort I'd removed the grain.
Charles , Yea it was unboiled , it was sealed up in the thermopot over night but it had dropped to around 40c.
I think I'll let it do its thing and see how it turns out , could be some sort funky sour brew.

Anyways lesson learnt.

Thanks for the replies

Andy

[andyCo]

Just got in from work and the shed still has a smell of off cheese vomit ....
The beers got a slight sour taste...not unpleasant just a bit strange

By boiling up the spoiled wort will I have any problems in the future with bacteria spores that may of soaked into the timber roof.


Andy

[Jocky]

Cheesy vomit smell comes from butyric acid, which is produced anaerobically by certain bacteria. Leave a pint of milk near a radiator and you'll end up with the same thing.

As Charles has said, the bacteria would have had perfect conditions once the temperature got below 50C. Boiling will have now killed everything, and denatured any nasty toxins, but your beer flavour will be permanently tainted.

In answer to your question about bacterial spores in the roof... you'll be fine. The steam will be 100C+ so anything caught in that should be well dead. Just make sure you keep any equipment that's come in contact with your spoiled pre-boil wort away from anything equipment/wort post boil.

[orlando]

I had something similar when a shagged pump meant I had to leave the mash in the thermopot overnight. Similar smells to the one you describe. Mine had a more pronounced acidic smell which I put down to the lacto bacillus that clings to malt grains, a reason for not milling grain near where you brew. Even though I went on to boil the resulting wort, it did not remove the lactic taste that had got a hold at those lower temperatures. Hope yours isn't the same problem or you will be dumping it down your drains like I had to.

[andyCo]

Jocky and Orlando , thanks for your replies.

After reading up abit and as jocky says it is butyric acid ...stuff really stinks and what I thought was some form of hot break was actually early fermentation.
I read of a beer called '3 days' by a Japanese brewery called Hitchino nest , they had an earthquake in 2011 and lost power to thier boilers.
They had the unboiled wort siting around for 3 days until the power was reinstated , they went through with the boil and fermented it .....apparently its a decent pint.
Unlike mine, slightly sour with a tinge of vomit wasn't doing it for me so I tipped it .

Shed smell's a bit better so hopfully all's good , plus its reassuring to know that I haven't got to nuke the shed .

Thanks again for the replies

Andy