Overnight mash cheesy smell

[The Baron]

Hilt
I have done quite a few overnight mashes but this one was left a little longer than normal around 20 hours ( work commitments made me late). Right the question is it has a funny smell like cheese no signs of anything else wrong so I boiled as normal for 45 mins and did the hop addition has anybody had any experience of this before and could it be the grains or other fermentables that have caused this as it did not just have 2.6kg of lager malt it also had 125 grams of cornflakes, 750 grams of cooked rice and 100 grams of porridge oats. Maybe the smell is from the cornflakes as it could also be described as a sweetcorn smell. I have used all these ingredients before to make a light american style lager with no problems it was 40C when I unwrapped it for the boil

 

[Covrich]

Hilt
I have done quite a few overnight mashes but this one was left a little longer than normal around 20 hours ( work commitments made me late). Right the question is it has a funny smell like cheese no signs of anything else wrong so I boiled as normal for 45 mins and did the hop addition has anybody had any experience of this before and could it be the grains or other fermentables that have caused this as it did not just have 2.6kg of lager malt it also had 125 grams of cornflakes, 750 grams of cooked rice and 100 grams of porridge oats. Maybe the smell is from the cornflakes as it could also be described as a sweetcorn smell. I have used all these ingredients before to make a light american style lager with no problems it was 40C when I unwrapped it for the boil

I am not saying this has happened but if the temp drops below 50ºc then the wort becomes ideal temps for wild yeast to sour it or give it a twang ..

YOu might be perfectly okay though

 

[The Baron]

I am not saying this has happened but if the temp drops below 50ºc then the wort becomes ideal temps for wild yeast to sour it or give it a twang ..

YOu might be perfectly okay though

I would have thought the boil would kill anything but I will ferment out and see what happens

 

[Covrich]

I would have thought the boil would kill anything but I will ferment out and see what happens

Not if the wort sours, it will kill what has soured but will not remove the sour from the wort.

 

[The Baron]

do you think I have made a sour beer? Only time will tell now if it does not go well I will not leave the overnight mash as long

 

[Sadfield]

Most likely the Lactobacillus bacteria naturally present in grain has produced isovaleric acid in the presence of oxygen. Your mash was likely on the way to souring.

Sent from my E5823 using Tapatalk

 

[The Baron]

smell seems to have gone once fermentation started so it may have a sour taste to it? I will update once fermented

 

[The Baron]

5 Days in and the fermentation as slowed right down so took a taste it does still have the chessy/sweetcorn smell (but not like the sweetcorn twang with kits) but the taste is not so prominent so I have decided to dry hop with 30g of Premiant to just try and disguise the slight off taste incase it does not dissipate with time. I did brew with some cornflakes in the mash and I wonder if that is the cheesy/sweetcorn taste but I think it is mainly due to leaving the mash too long as it went down to 40c from 66c and that may have caused the issue. It is probably more prominent as it is a very light american style lager/kolsch of 12 ibu's. I will not leave my next overnight mash as long with the same recipe to compare and I will give the fermenter used a good oxi and clean just incase it had a infection but no other signs like unusual activity or scum on the top etc so think the mash has just soured with being left too long me thinks