Do we oxidize the wort on the hotside?

[Elysium]

I have just read John Palmer's chapter on the relation between oxygen and the wort.
The reason why I got there is because I suspect that we oxidize our beer on the hot side while cooling it down to pitching temperature.

We have no chiller at all....we use a water bath and it takes about an hour to cool the wort to the ideal temperature of 73.5F.

Basically we put it in a bath and then stir it....now the stirring part might introduce oxygen that binds to something in the wort and produces this weird, hot-alcoholic, leathery, antiseptant taste. It is pretty much present in our last few batches and even before that.
We dont splash the wort......we stir it nice and slowly....but still, it might be the oxygen. Any ideas?

 

[rockbasementbeer]

Oxidation gives more of a cardboard off-flavor, so i would doubt that this is your issue. Not to mention you have to aerate your wort before pitching yeast anyway, they need the oxygen for reproduction

 

[rockbasementbeer]

Sounds like fusel alcohols to me

 

[alane1]

^^^^What he said, hot side aeration is a fairly uncommon problem that doesn't show up for months. Fermenting warm is noticeable right away.

 

[Elysium]

Sounds like fusel alcohols to me

Agreed, but that is caused by high ferm. temp. We ferment at 60-62F. So....no clue then what causes it.

 

[rockbasementbeer]

what yeasts are you using?

 

[alane1]

Is your water treated with chlorine?

 

[jro238]

Leather can be a flavor associated with oxidation. What is the ABV of your beer and is the alcohol flavor more like *good* vodka or rubbing alcohol?

Last, is the antiseptic flavor medicinal or band-aid like? Or is it more like rubbing alcohol?

 

[BigFloyd]

Based on what you described, HSA (hot side aeration) would be rather low on the list of suspects for producing off-flavors. There's something of a debate as to whether it truly exist in homebrewing.

Since I brew on a recirculating electric BIAB system, I probably move warm/hot wort around a bit more than most brewers. I've never picked up any oxidation-related flavors. IMO, unless you badly abuse your mash/wort, the potential effects of HSA may be so slight that you won't even taste them.

 

[Elysium]

Leather can be a flavor associated with oxidation. What is the ABV of your beer and is the alcohol flavor more like *good* vodka or rubbing alcohol?

Last, is the antiseptic flavor medicinal or band-aid like? Or is it more like rubbing alcohol?

It tastes like bad vodka...
I think it is more like alcohol.....like the one you would buy to treat a wound or sanitize something...

 

[jro238]

It tastes like bad vodka...
I think it is more like alcohol.....like the one you would buy to treat a wound or sanitize something...

Yeah, that's pretty textbook fusel production then. Are you 100% sure that you fermentation temp is in the low 60s? (fermentation temp, not ambient temp). Calibrated thermometers etc?

 

[Johnnyhitch1]

How is your crush and mash procedures?

High pH when mashing will cause tannins and astringency to increase

 

[VladOfTrub]

High ferment temps aren't the only cause of fusels. Poor wort pH, low oxygen rate during yeast respiration stage, low nitrogen content or nutrient starved yeast will form fusels when the ferment temp is in the park.

 

[Elysium]

High ferment temps aren't the only cause of fusels. Poor wort pH, low oxygen rate during yeast respiration stage, low nitrogen content or nutrient starved yeast will form fusels when the ferment temp is in the park.

The Ph is between 5.6-6.........low oxygen: I doubt that would be the case. We aerate with a handmixer for 10 minutes.
Low nitrogen, starved yeast......possibilities.

 

[rockbasementbeer]

What are the OG readings for the beers and are you doing starters?

 

[Elysium]

What are the OG readings for the beers and are you doing starters?

We rehydrate the yeast...since it is a dry yeast (safale US-05) 11.5 grams, more than enough for a 6.5 gallons batch.
The OGs were different....mainly at between 1.048-1.052