Overnightmash with Off-flavor at the beer

[Smarley]

Hi,
I started to use overnightmash technique in my last brews.

In fact, I start the mash around 6:30 and continuous when came back from work around 17:00.
Before this I did one using traditional method with the same cooler and mash around 1:30h. Before the cooler was using BIAB for several batches.

I bought a cooler from Coleman, the simple one like this, and use a bazooka inside: https://www.amazon.com/Coleman-3000000-48-Quart-Performance-Cooler/dp/B002V9XV9K

Did this 3 brews with this technique:
1 - German Pilsner
2 - IPA
3 - Dunkel
I did one by week.
All with new yeast

In this 3 beers, I noticed the same off flavor.
It's kind of a refresh, fluorine, toothpaste.
But it´s not chlorophenol, the water filter it´s working fine, it´s not medicine like taste.

The first one, I will need to throw away, it´s very strong the taste.
Ipa, has less of it, and Dunkel a little bit like IPA maybe.

Has anyone got this problem with cooler using overnightmash?

Thank you.

 

[Dgallo]

How well is it holding temp during the time?

 

[S-Met]

1st time using the cooler as a mt? If so, it sounds like you may be getting off flavor from the plastic. I'd suggest trying with your kettle and see if the problem persists.

Since it was bad at first but improving, May need to leave the cooler open in the hot sun for a day or 2 to try and off-gas some of the funk.

 

[Smarley]

How well is it holding temp during the time?

Start with 65°C and end around 58°C.

 

[Smarley]

1st time using the cooler as a mt? If so, it sounds like you may be getting off flavor from the plastic. I'd suggest trying with your kettle and see if the problem persists.

Since it was bad at first but improving, May need to leave the cooler open in the hot sun for a day or 2 to try and off-gas some of the funk.

Yes, could be, that was my last thought.
Because at the dunkel it's almost imperceptible.
I think fermentation will consume this off-flavor son.

It´s normal in the first time using the cooler?
Has a procedure for that?
Saw very people using and converting their coolers, but never talk about this.

 

[Dgallo]

Start with 65°C and end around 58°C.

Ok that still warm enough that the wild bacteria on the grain wouldn’t be able to to ferment any off the wort and throw any off flavors.

If you read up on LODO brewing techniques, there might be a answer for you. Just like hop compounds can oxidize, so can grains and ruin flavors. Unless you boil your mash water and then cool to temps and transfer it without splashing, there will still be a lot of disolved oxygen in the water. Your mash is probably oxidizing quite a bit with that extended contact time. This flavor can’t be boiled off or cleaned up through fermentation.

If I’m you, I’m doing my next brew with a traditional mash and comparing the outcomes. See if it’s the same or better. If it’s better, stop overnight mashing. If it’s not better, start looking into your fermentation health and post fermentation procedures.

 

[Miraculix]

Long contact time between hot water and brand new plastic and kind of chemical taste as a result.

Les strong taste each batch.

Is pretty obvious that the plastic is introducing its solvents /hardeners /softeners into the water.

I honestly wouldn't drink it and ditch the whole mash ton.

 

[Smarley]

Long contact time between hot water and brand new plastic and kind of chemical taste as a result.

Les strong taste each batch.

Is pretty obvious that the plastic is introducing its solvents /hardeners /softeners into the water.

I honestly wouldn't drink it and ditch the whole mash ton.

I will do a experiment, put water at 70C, leave there, and taste it, if has something different.
And leave the cooler at the sun some days too.

 

[Smarley]

Anyway, next batch I will do in the tradicional method around 1~1:30h of mash.
I did one with the same cooler in this method and did not feel wrong.