Have I oxidised my beer?

[coloneldom]

So, in a rush to finish my beer prior to heading to my night shift at work, I transferred my wort, approximately 15 L worth, via siphon into the fermenter while it was still sitting at about 40 degrees Celsius. It splashed quite a bit, so after reading up a little bit I'm concerned that I've oxidised my beer. I still need to top it up to 18 L and yeast is yet to be pitched, but do you think this will ruin my beer?

Cheers for any help in advance!

 

[philmud]

Prior to pitching you WANT to oxidize (well, aerate) your beer. It's essential for yeast reproduction. It's the finished beer you don't want to oxidize.

 

[manticle]

You mean hot wort?
You may have encouraged certain staling reactions but cold side packaging is more important. Some oxidation is inevitable, no matter how cautious you are. The results will vary depending on so many factors, so just be as careful as you can when transferring and let nature take its course after that.

 

[MaltyHops]

Probably should be more worried about something unintended taking hold of your warm wort since you didn't pitch your yeast.

 

[manticle]

Prior to pitching you WANT to oxidize (well, aerate) your beer. It's essential for yeast reproduction. It's the finished beer you don't want to oxidize.

When the wort is cool, yes. Not at 40 degrees.

 

[squirt in the turns]

Probably should be more worried about something unintended taking hold of your warm wort since you didn't pitch your yeast.

This, definitely.

How long will your hot/warm wort be sitting without yeast in it? I get the rushing to finish before work thing - I've been there, but you'd have been better off no-chilling or even leaving to cool, covered, in the kettle.

 

[philmud]

When the wort is cool, yes. Not at 40 degrees.

I did not know that!

 

[manticle]

Look up hot side aeration. Then listen to charlie bamforth podcast about hsa and development of transnonenal and its contribution to oxidation and staling reactions. It's not instant death for beer and in some/many cases, the risk and effect is overstated but the risk is there nonetheless -aerating wort much above about 35 degrees (memory - please check actual figure) can commence or accelerate certain oxidation reactions.

 

[coloneldom]

I appreciate the answers gents, I'm hoping the relatively small volume of wort I've transferred means that the off flavours potentially created won't be too overpowering.

Reading up on hot side aeration is pretty interesting and their is some pretty heated debate on the topic on other forums about whether it's a huge concern at my level,

But I guess it's just a wait and see from here, noted for next time though. I've really got to realise that that seems to be the answer for most of my panicked newbie questions haha.

 

[The Judge]

I transfer my wort from boil kettle (after chill) to fermenter via a 1 meter drop through the air so that there's plenty of contact with the air, and I let it foam and slosh at the bottom of the fermenter for additional aeration. Never had any off flavours from this method, and always have good yeast growth.

 

[manticle]

No reason chilled wort should give off flavours if splashed. Hot wort, fermenting wort in anaerobic phase and finished beer are different story.

 

[coloneldom]

At what temp do you consider your wire chilled enough to transfer? As I understand it 40 degrees was pushing it. John Palmer suggests below 26 even!!

 

[manticle]

I wait till it's at ferment temp.

 

[Moad]

So a CFC is a risky way to chill? Pumping liquid around is sure to expose it to oxygen right?

 

[manticle]

It's more about splashing/agitation and I understand you need to splash a lot for it to be an issue. Furthermore it may often be no issue - find the podcast I refer to above for more info. Cold side splashing (fermented beer not unfermented wort) is far more of an issue than hot side. Hot side is just something to be aware of and reduce agitation where easily possible (or not - some home brewers consider it a non-issue).

 

[manticle]

http://www.thebrewingnetwork.com/shows/475

 

[Black Devil Dog]

Look up hot side aeration. Then listen to charlie bamforth podcast about hsa and development of transnonenal and its contribution to oxidation and staling reactions. It's not instant death for beer and in some/many cases, the risk and effect is overstated but the risk is there nonetheless -aerating wort much above about 35 degrees (memory - please check actual figure) can commence or accelerate certain oxidation reactions.

I always avoid HSA when transferring into a cube, but I recall an article somewhere that basically said that because yeast consume oxygen, any aeration done while the wort is hot, will be taken care of by the yeast during fermentation.

This may only be the case if the wort is cooled to pitching temp quickly though. I no chill and store my cubes for several weeks, hence my avoiding HSA.

 

[Black n Tan]

I always avoid HSA when transferring into a cube, but I recall an article somewhere that basically said that because yeast consume oxygen, any aeration done while the wort is hot, will be taken care of by the yeast during fermentation.

This may only be the case if the wort is cooled to pitching temp quickly though. I no chill and store my cubes for several weeks, hence my avoiding HSA.

HSA causes compounds in the wort to become oxidised (oxygen becomes covalently bonded to the compound), such as long chain unsaturated aldehydes that get oxidised to Trans-2-Noneal which has a cardboard stale taste. The yeast will not consume these compounds like it does free oxygen. So as Palmer says aeration is good, oxidation is bad.

 

[coloneldom]

Alright, thank you all for your answers and help. Let's put a little hypothetical out there though, assuming I have buggered up and I have oxidised my beer, is there anything I can do to minimise the production of off flavours?

 

[manticle]

Nope. Not as far as I know anyway - mostly irreversible chemical pathways. However not all flavours relating to oxidation are bad. Some are welcome in the right amount in the right beer. Suck it and see.