MT to Boiler - Why minimize splashing?

[SiHoltye]

Just read to minimize splashing preboil, wondered why, and what problems if not?

While we're at it, I think if you sparge with too hot liquor you risk extracting tannins from the grain husks. What is too hot and can the result of extracting tannins be explained?

Many thanks anyone.

[delboy]

Its supposed to cause the bogey man of homebrewing 'Hot side aeration' (HSA) its suggested that introducing oxygen to the wort when it is warm causes the beer to go stale quicker.
Its one of those things though that seems to get bandied about but nobody actually seems to have experienced, maybe the water treatment that homebrewers do with camden tablets (an excelllent oxygen scavenger) protects us from it or maybe its just an urban myth.
I suppose it would be prudent to try and reduce splashing etc but not to get to hung up about it.

Tannins are extracted from the grains at high temperatures you probably don't want to go above 80 C or so.
The tannin would cause an astringency in the beer a think you are supposed to sense astringency on the toungue.

[SiHoltye]

Ta DB,

My sparge is usually 80-90° if I've checked. I'll keep it to just under 80° if I can tomorrow, and also fit a tube from MT tap to bottom of boiler on sparge.

Tweak, tweak, tweak!

[SiHoltye]

I use 5.2 buffer in my MT, but in all honesty don't look at the gravity of runnings and just sprage to the boil length of the recipe. How do you easily check SG when it needs to be adjusted for temp and while you're doing that the tap is still open? Not being facaecious, am really interested if it makes better beer. Is there a table (matrix style perhaps) for adjusting temp. There is this function in the beersmith software I use but the PC is upstairs, and the MT will not be!

[delboy]

I use 5.2 buffer in my MT, but in all honesty don't look at the gravity of runnings and just sprage to the boil length of the recipe. How do you easily check SG when it needs to be adjusted for temp and while you're doing that the tap is still open? Not being facaecious, am really interested if it makes better beer. Is there a table (matrix style perhaps) for adjusting temp. There is this function in the beersmith software I use but the PC is upstairs, and the MT will not be!

For rapid gravity readings, a refractometer (about £15) is the way to go, i didn't understand how to use it (the calcs) at first but now i know how to its the bees knees. You can take a reading in the a few seconds.
Look up the refractometer thread in the brewing equipment section.

Do you fly or batch sparge?

Fly sparging tends to be more critical!!

[SiHoltye]

I'm a fly sparger. I think I'm getting it now. What I need to do mentally is accept this is another step I should undertake and not bury my head in the sand 'cos it sounds like a hassle!

The mash is on now so I'll move the trial and hydro next to the MT.

My technique refinement points today are to use sparge liquor at the correct temp (~77°) and not to drop from height into my boiler but to minimize aeration at this point.

Also I think when I'm within the final gallon of brewlength in the boiler I'll take a sample of runnings from the MT, close the tap and see what SG I'm at. That sounds easy enough and I can sparge as usual to the 4 gallon point. 1.010's the magic number so I'll try to stop at that.

Thank you for your help.

[Aleman]

I've been doing a lot of reading around HSA, and from what I have come to understand, the problem seems to have arisen from a particular type of 6 row malt used in the US. I can't recall the details and its all to long winded to mention here, but the malt contained high level precursors of trans 2 nonenal (Cardboardy taste/aroma), these were oxidised following exposure to air during and after the mash, and subsequently showed up in the stored beer.

It appears to be restricted to a 6 row US malt (so our Maris Otter / Pipkin / Halcyon etc are fine), and if brewing darker beers where the darker malts act as an anti oxidant then again the problem is eliminated/reduced.