I aerated my wort after fermenation!

[homebrew_handyman]

I will not lie I went to wake up some of my yeast and a week after fermentation had begun I stirred my wort far to much. Without even thinking I added air and oxygen to mu fermenting wort. I stored with a whisk pretty hard for 30 seconds before a caught myself. What js going to happen to my stout now? It still has .030 to reach final gravity. So I'm thinking two more weeks till secondary but how will the extra oxygen affect my batch? Thanks.


Fyi don't be enjoying too much homebrew while home brewing.

 

[MrsMichelle]

The chances are there was WAY more C02 in the fermentation vessel and you probably didn't do much harm. But in the future if you want to wake them up (so you say) just rock the fermenter or do "swirl" thing to it.

M

 

[homebrew_handyman]

Thanks. I have brewed a lot of batches in my day and for some reason completely slipped my mind. I thought that seemed far to easy. I did get a goo layer of bubbles on the top of my wort. Your saying the Co2 will force any sneaky O2 out?

What is the harm with getting to much oxygen into that wort. This is a stout that need to condition for a while and will the O2 cause it to go bad? Thanks again.

 

[m1batt1]

Oxygen in wort is good as the yeast use it in their processes. Oxygen in finished beer causes oxidation which over time leads to off flavors. Given that your beer isn't done fermenting I'd say the yeast and co2 should take care of any oxygen you introduced by either utilizing it or scrubbing it out of solution.
IF there's oxygen left over once fermenting is done it could create the cardboard off flavor everyone describes but the only way to know is wait and see. I'd personally say you're fine though since its still working.

Sent from my SGH-I747 using Home Brew mobile app

 

[Wispering_Eye]

Oxidation effects beer flavor in a few ways. The most unpalatable occurs mostly in light-colored beers: the formation of trans-2-nonenal. This compound, which is classified as an aldehyde, tastes like paper or lipstick (lipstick and paper actually taste quite similar!). It has a very low flavor threshold; as little as 0.1 parts per billion can be discerned in beer!

The aroma of many light-colored beers will also be compromised by oxidation. The malt character that is originally present in a fresh example may become honey-like due to the formation of 2,3-pentanedione. While this may not be unpleasant, it may not be what the brewer intended.

Dark beers tend to be affected differently. As they age, rich malt aromas are replaced by sweet, sherry-like tones. Many people find this aroma enticing, although it is much different from the original malty character of the fresh beer. Most concerning, the malt flavor of the beer disappears, leaving an emptiness in the palate that can be quite disappointing.

These sherry characteristics are the result of the oxidation of malty-tasting chemicals called melanoidins. Their oxidation products have a wide range of flavors, one of which is the almond-like benzaldehyde. Together, the different compounds are responsible for the flavor of sherry.
http://www.professorbeer.com/articles/oxidative_staling_beer.html

 

[Cyclman]

Just drink it fast, throw a party.

 

[BigFloyd]

A week into it, the yeast had progressed well from their initial respiration and reproduction (when they consume the dissolved O2 in the wort) into anaerobic fermentation (when they produce alcohol and CO2).

Opening the fermenter and whisking air into the liquid after that happens could very well have two effects that you don't want -

1) oxidation (as already mentioned) and,

2) the yeast may cease anaerobic fermentation and switch back to aerobic respiration. After they consume the late-added O2 (using it and the sugars for their own benefit producing certain co-enzymes), they may have problems fully converting back to fermentation mode again. It could end up stalling the fermentation.

 

[homebrew_handyman]

I took a hydro reading and got 1.034 which is only .015 away from my goal of 1.019. I will check again tomorrow but it appears things have picked up. Hope the extra oxygen I added would ruin this one. It smells great and tastes good too, still a little on the sweet side but a week or ten more days in primary should take care of that. Thanks folks!