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General Category => General Homebrew Discussion => Topic started by: morticaixavier on July 07, 2011, 08:51:56 PM

Title: Hot Side Aeration and Coffee
Post by: morticaixavier on July 07, 2011, 08:51:56 PM
So I know there is a lot of disargreement around HSA and I am not a sophisticated enough brewer to really worry about it. I don't stir my hot wort with a mix stir but I don't coddle it either as it cools.

But I have been making ice coffee in the morning for the afternoon as the temps here in NorCal start to rise and I noticed an interesting phenomenon. I brew my coffee with one of those low tech cones that just sits on top of my termal mug. about 2.25 cups of water that was boiling and then poured into a pyrex measuring cup before being poured through about a cup of grounds (medium roast if anyone cares) I like my coffee strong. I also stir the grounds in the cone while it is draining to squeeze every last drop of goodness out of them. I was then pouring the finished coffee into a glass jar and lidding it immedietly with very little headspace. And in the afternoon I kept noticing that there was a cardboardy flavour to the coffee. So I starting thinking about HSA. This morning I did everything the same as above except while pouring into the glass jar I was very careful and slow so as to minimize splashing and low and behold my coffee this afternoon has no cardboardy taste!

Is this proof of the effects of hot side aeration even on a very small scale? I don't know what do you all think? Am I completely obsessed? (My wife thinks so, everytime I say 'I wonder what a beer with x would be like')

I don't imagine it's going to change my brewing techniques but as I said I already don't splash things around till they are cool.
Title: Re: Hot Side Aeration and Coffee
Post by: oscarvan on July 07, 2011, 09:34:25 PM
Yes. But, that's not a bad thing.
Title: Re: Hot Side Aeration and Coffee
Post by: tschmidlin on July 07, 2011, 10:16:35 PM
Coffee is very susceptible to oxidation.  Oxidation happens faster at warmer temperatures.
Title: Re: Hot Side Aeration and Coffee
Post by: gmac on July 07, 2011, 10:23:20 PM
(medium roast if anyone cares)
I care...
Title: Re: Hot Side Aeration and Coffee
Post by: morticaixavier on July 07, 2011, 10:30:41 PM
I suppose in a beer situation the tendency of the yeast to scavange o2 makes it less of an issue though huh?
Title: Re: Hot Side Aeration and Coffee
Post by: tschmidlin on July 07, 2011, 10:45:41 PM
On the hot side there isn't any yeast, and that is when the HSA can be a problem.  However I don't believe it is a problem on a homebrew scale following normal procedures.
Title: Re: Hot Side Aeration and Coffee
Post by: morticaixavier on July 07, 2011, 10:47:14 PM
On the hot side there isn't any yeast, and that is when the HSA can be a problem.  However I don't believe it is a problem on a homebrew scale following normal procedures.

Right, but doesn't it take time to have an effect? and wouldn't the introductio of yeast then remove much of the O2 thus preventing the effects of HSA? or perhaps i am speaking out of my a$$
Title: Re: Hot Side Aeration and Coffee
Post by: tschmidlin on July 07, 2011, 10:53:25 PM
I can't say for sure since I haven't experienced it.  But boiling would drive out the O2 anyway, so the HSA products would have to be formed in the mash/sparge.  Unless you are introducing O2 prior to chilling.  The reactions will happen faster when it is warm, so chilling it would slow it and adding yeast (which will take up the O2) will stop it.  I'm not sure I would call it HSA if the wort was at yeast pitching temps though. :-\
Title: Re: Hot Side Aeration and Coffee
Post by: bluesman on July 08, 2011, 02:03:31 AM
I can't say for sure since I haven't experienced it.  But boiling would drive out the O2 anyway, so the HSA products would have to be formed in the mash/sparge.  Unless you are introducing O2 prior to chilling.  The reactions will happen faster when it is warm, so chilling it would slow it and adding yeast (which will take up the O2) will stop it.  I'm not sure I would call it HSA if the wort was at yeast pitching temps though. :-\

So we introduce oxygen during mashing then we drive it off during the boil, then we introduce more oxygen prior to ferment and then the yeast scavenge all of the available oxygen during fermentation.

I think it all makes sense now.  ::)  :-\
Title: Re: Hot Side Aeration and Coffee
Post by: gmac on July 08, 2011, 02:59:01 AM
I run my lauter into a bucket, then I pour the bucket into the brew kettle and then I sparge again into the bucket and pour that into the kettle.  Bubbles-a-plenty.  I haven't noticed any off flavours, cardboard or otherwise so I've stopped caring about HSA.  I can't see how you could do much worse than I do without putting your wort in a blender.
Title: Re: Hot Side Aeration and Coffee
Post by: classic on July 08, 2011, 04:32:22 AM
I have heard that Anchor Steam intentionally transfers their hot wort in such a way that it is aerated. I don't know why they do this, but presumably they wouldn't if it caused stability problems.  Anyone know of other production brewery practices with regards to HSA?  I will say that I have noticed a significant cardboard taste in a light roast of coffee beans I have used in the past. Even fresh through from the carafe it tasted awful, never occurred to me that HSA was possible in other liquids. How about in tea, soups, etc?
Title: Re: Hot Side Aeration and Coffee
Post by: tschmidlin on July 08, 2011, 05:05:54 AM
Pretty much anything can oxidize, with at least the exception of gold. ;)

It won't always lead to a disagreeable flavor and aroma though.
Title: Re: Hot Side Aeration and Coffee
Post by: euge on July 08, 2011, 08:20:23 AM
I can't say for sure since I haven't experienced it.  But boiling would drive out the O2 anyway, so the HSA products would have to be formed in the mash/sparge.  Unless you are introducing O2 prior to chilling.  The reactions will happen faster when it is warm, so chilling it would slow it and adding yeast (which will take up the O2) will stop it.  I'm not sure I would call it HSA if the wort was at yeast pitching temps though. :-\

So we introduce oxygen during mashing then we drive it off during the boil, then we introduce more oxygen prior to ferment and then the yeast scavenge all of the available oxygen during fermentation.

I think it all makes sense now.  ::)  :-\

This is how I envision it. Never had a problem, but still wonder why people view it as such at the homebrew level. Would the mistreatment have to be so flagrant as to have an effect?

Yes. But, that's not a bad thing.
Esplain please.

I'll chill coffee if it isn't going to be consumed. Beer glass filled with cold coffee out of the fridge and a little sweetener and no ice... Bzzzzz.
Title: Re: Hot Side Aeration and Coffee
Post by: EHall on July 08, 2011, 04:30:22 PM
'Pretty much anything can oxidize, with at least the exception of gold.'

thats why I only eat gold soup...
Title: Re: Hot Side Aeration and Coffee
Post by: bluesman on July 08, 2011, 04:40:17 PM
I do know that Charlie Bamforth has stated that there is continuing research on the HSA issue and it's effects on the finished beer. There are so many reactions that occur during the mashing, boiling and fermentation, that it becomes difficult to isolate any one particular variable and nail it down on the homebrewing scale. I think we should use our senses and make sensible (no pun intended) decisions on how we handle our process.

In other words "How does your beer taste" or "How does your beer smell". These are our indicators for potential concerns or faults in the finished beer.