Oxidized flavor.

[bronson]

G'day all,
I recently entered the MM specialty IPA comp and in two of my score sheets "oxidised" was mentioned.
What is this? How do I overcome it.

my technique was as follows

biab
immersion chiller
us 05
cupboard fermentation next to the thermostat. house at steady 19c 12 days
secondary 10 day W/dry hop
3 day cold crash
syphon to bottle bucket
bulk prime w/ dme
cap bottles return to cupboard

Am I conditioning at room temp to long?
When is optimal time to refrigerate?

Any pointers would be tops.
thanks in advance. B :kooi:

 

[breakbeer]

Potentially during racking to secondary

What was your process?

 

[bronson]

I split the batch and had 2 neverfail water jugs.
All I did was dump a heap of hops (full cones) in the jug and the syphon beer in and cover top with glad wrap.
the other with same qty of hops but rum barrel oak chips also.

 

[labels]

Oxidation can occur at any point in the process. What is important to understand is that once something oxidises, it stay oxidised even if you then take it into an environment where no oxygen is present. So, it can happen before fermentation or afterwards.

The BJCP judge sheet guideline states: Any combination of stale, winy/vineous, cardboard, peppery or sherry like flavours. sherry is a deliberately oxidized wine and cardboard mainly refers to beer tasting like wet cardboard smells.

Try to keep oxygen out of your beer except immediately at pitching time where, if you pitch sufficient yeast they will use up the oxygen pretty quickly before oxidation occurs

 

[breakbeer]

I hate siphoning, maybe I had a shit one or wasn't using it properly, but there would always be air in the tubing during transfer. Did you notice any when transferring to the neverfail jugs or bottling bucket?

As a result, I never use a siphon & never, ever transfer to a secondary fermenter

 

[TheWiggman]

When you rack to your secondary the beer is exposed to a pocket of air for 10 days. This is a good chance for O2 to begin it's work and will only worsen down the track. If you keg, purge your fermenter with CO2 before and after transfer and you'll minimise oxidation.
Additionally, anything on the shelf will oxidise over time. The older they were when they were judged, the more likely they were to suffer from oxidation.
If I were in your shoes I'd cut the secondary unless you have a good reason for it. Also, don't be too cut. There's oxidation, and there's OXIDATION. Minor degrees of it are perfectly drinkable and if bottled over time it's inevitable.

 

[bronson]

So my next question is, I automatically thought it was a bad thing... is it?
I think the beer tastes great anyway ha ha
:drinks:

 

[barls]

some have a lower threshold for things.
for me oxidation in a hoppy beer is the hop flavour morphs into a dull generic flavour.

 

[Jaded and Bitter]

It could be during mashing. The high temp mash is far more vulnerable to oxidation precurses than room temperature beer, which has about 1.2 volumes of CO2 dissolved. Have a look at your mashing methodology and see if theres anyway it is getting excessively aerated.

If your racking to secondary the advice I got when I was a pup was to do it when primary was nearly finished, not when it was finished. I'm sure you can guess why.

But as The Wiggman says theres oxidation and then theres OXIDATION. Hey some of my beers probably have some oxidation, although I cant detect it.

Its like worrying if your beer is skunked, until one day you taste truly skunked beer.