Is pre- dough-in Hot Side Aeration possible?

[carpedaym]

Uh-oh, look out. Noob with HSA question!

If you aerate your hot water BEFORE adding your grains to the mash, will the oxygen eventually bind to the proteins, possibly causing downstream hot side aeration?

I ask because the hot water in my house comes out at about 65c (hmm, convenient). If I stick my BIAB pot under the bath tap, I'd be well on my way to dough-in temp. However there'd be a heck of a lot of aeration happening as it filled. Can I do this?

I've done some reading & listened to a few podcasts on the issue, but haven't found anywhere this is clarified. They always talk about not to splash the "wort" (as opposed to "water" or "hot liquor") and that is can occur "during" the mash (again, ambiguous).

To be honest, I have some sodium meta-bisulfite lying around so I'll probably throw a pinch of that in as suggested in previous threads, but I am a curious kitten who would like to know anyway. ^_^

 

[sponge]

From a professional brewer, he stated that (on a homebrew scale) you can pretty much let the wort dribble and splash into the kettle from a metre height if need be, as it will get boiled out of solution anyways, and anything left over will be used by the yeast during the lag phase of fermentation.

I wouldn't be concerned.


EDIT: I know you were talking about liquid into the MT, but I believe (and am happy to be proven wrong) that it would be a similar situation anywhere pre-boil.

 

[Florian]

I'm sure every third brewer transfers their water from the hlt by splashing it into the mash tun, but if you're worried about it just attach a silicon hose to the tap going to the bottom of your vessel.

 

[heyhey]

Hot water is less likely to dissolve oxygen into the water and the splashing could actually disturb dissolved oxygen and cause it's release. (just hypothetical)

If you're worried about it, as said, put a silicon hose over the tap and another thing might be to remove the strainer/aerator cap if there is one on the tap.

And are you measuring temp of the water to see if it is actually 65*C?

 

[carpedaym]

I certainly do NOT want to start any debate again. Just trying to play it cautious and scientific. I'm keen to narrow down the possible causes the inevitable critical feedback on scoresheets.

The hose suggestion sounds wise. I had figured I'd need some sort of threaded tap situation, but it sounds like I should just be able to work the hose it over the tap nossle(?)

And are you measuring temp of the water to see if it is actually 65*C?

Yes, I have done a quick and dirty measurement of this.

I expect I may have to throw the pot on the burner for a few minutes anyway to hit my mash-in temp, at least for some brews.

 

[Mardoo]

Have a read of some of Charles Bamforth's articles on HSA, or listen to the BN's Brew Strong podcasts with him as guest. A lot of good science done on the subject. And he's a fascinating speaker and real character.

Here's the Charles Bamforth BN Brew Strong episode on HSA:
http://www.thebrewingnetwork.com/shows/475

 

[Black n Tan]

I ask because the hot water in my house comes out at about 65c (hmm, convenient). If I stick my BIAB pot under the bath tap, I'd be well on my way to dough-in temp.

Have you tasted your hot water straight from your tap? Mine doesn't taste very good and as such I would not use it in my mash. Better to use cold water and heat it up. Do others here use hot water from their tap in the mash?

 

[manticle]

I do.

In my old place it was cold, heated up. Not noticed any discernible difference in the resulting beers - just less electricity used as my HW system spits out very hot water.

OP: Splashing hot water pre- dough in makes exactly eleven 15ths of a 1% differential of the ratio of the genitalia of small black ants' (when compared with honeybees) worth of difference to the end result of your mash and the resulting beer.

HSA is one possible contributor to oxidation and staling. It is not easy to make occur - nor is it easy to prevent oxidation and staling aldehydes in finished beer but concentrating on careful cold side/packaging etc and reducing unnecessary splashing on the hot side is all the precautions you need.

Are you getting trans-2-nonenal/cardboard flavours in your finished beer?

 

[Bizier]

Yeah, you want good quality hot liquor. I would adress absolutely everything else under the sun before looking into the O2 of your HLT.

 

[carpedaym]

Cheers guys. Appreciate the experienced opinions here. I will press on as planned!

I've tried some cooled hot-tap water and it tastes just fine.

Manticle, I've only done 2 AG brews previously, but both were before I got my bigger pot and before moving to Melbourne (i.e. different process). An Irish Red which apparently had some solventy flavours to it. I haven't really nailed down the cause to anything yet. The other was a pilsner I was pretty chuffed with, which probably only needed recipe tweak & water adjustment.

 

[manticle]

Solvent is likely a fermentation issue or a yeast stress issue (not enough for the gravity). HSA from HLT is the last thing to be concerned about.