Why do we sparge with hot water?

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olie

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My understanding is that we want to sparge with hot (180-190°) water "...in order to stop all enzyme activity".

But why? All this wort is headed to the boil pot where, in just a few minutes, it's going to be boiling, anyway. And it's not like mashing for an extra 30 min (let's say) hurts anything.

So why does it matter that we sparge with enzyme-stopping temperatures? What's going on there? Put another way, how would the final beer turn out different if I sparged with mash-temp water (say, 155°)?

(Yeah, yeah -- "do the experiment and report back". That would be one way; but I'm trying not to ruin perfectly good recipes, and just gain some understanding.)

Thanks!
~Ted
 

bracconiere

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i believe fermentabilty set point...and no this is called a mash out step, i personally don't do it...if i remember people that bring it up 168f not 180-190...that kind of heat and you run the risk of tannin extraction, kinda give beer a yeasty/astringant feel/taste....

and yes mashing an extra 30 minutes will change the FG...it's been so long since i haven't added gluco to all my beers, so it's a distant memory for me though!
 

BigEd

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A mashout rest (170F/76C) is designed to denature enzymes. Once the mash has done its job you want it to stop working or longer chain sugars will continue to be broken down. If you do not do a mashout higher temperature sparge water can be used to do a sort of all-in-one mashout/sparge. Otherwise a sparge water temp the same as mashout rest would be recommended. Higher temperature water also tends to more easily dissolve sugar molecules.
 

bracconiere

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Once the mash has done its job you want it to stop working or longer chain sugars will continue to be broken down.

to clarify that's what i meant about fermentability....for the OP, long chain sugars will add residual sweetness to a beer, and give it a higher final gravity...
 
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Yooper

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I think we need to get the terms correct here.

My understanding is that we want to sparge with hot (180-190°) water "...in order to stop all enzyme activity".
That is not a sparge- that is actually a mash-out.

We don't necessarily sparge with hot water- if we are doing a mash-out, the brewer will use hot enough water to bring the grainbed to 168F long enough to denature the enzymes.

After that, if we sparge, we can sparge with ice cold water if we want to. Sparging with hot water (under 170 degrees) at that point has only one benefit- to help get the wort to a boil faster than using cold water.
 

3 Dawg Night

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We don't necessarily sparge with hot water- if we are doing a mash-out, the brewer will use hot enough water to bring the grainbed to 168F long enough to denature the enzymes.
We batch spargers are, in essence, combining the mashout and the sparge into a single step.
 

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We batch spargers are, in essence, combining the mashout and the sparge into a single step.
Yes, exactly. If you do two rounds of batch sparging, the first one may be near 200F (to get the grainbed up to 168F), but the second should be no more than 168F to avoid tannin extraction. The thing is, a quick batch sparge isn't long enough to denature the enzymes usually so it may not be all that helpful.
 

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When I batch sparge, I usually don't bother with a mashout, since the runnings go onto boil as soon as they leave the MLT. And lately I've been doing a full volume mash, so I just run off and start it onto boil without a mash-out.
I guess that's the key. With batch sparging, there's only ~10 minutes between mash and heating for the boil. I've never fly sparged, but my understanding is that it can take up to an hour, during which time the enzymes are continuing to work. A mashout is probably more critical there.
 

Velnerj

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I'm not sure about tanin extraction at high temps due to the fact that some of the best beer in the world is triple decocted (boiled three times). If that doesn't extract tanins I'm not sure hot batch sparging will do it either.

I use hot water for three reasons 1)mash out and keep desired long chain sugars to improve mouthhfeel sweetness etc.
2) maltose is much more soluable in hot water so it can improve efficiency (or at least time)
3) takes less time to reach a boil after the lauter.
 

bracconiere

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I'm not sure about tanin extraction at high temps due to the fact that some of the best beer in the world is triple decocted (boiled three times). If that doesn't extract tanins I'm not sure hot batch sparging will do it either.

i do triple decotion too? i googled it, it's not boiled it's just a protein rest at 120f~, an acid rest (don't know the temp never done it), and a sacirifcation rest....not boiled....


my third step is a rest at 160-162 for alpha amylase....i do boil the running from the tun and add it back to raise the temp...but tannins are in the husks not the wort....
 

Velnerj

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i do triple decotion too? i googled it, it's not boiled it's just a protein rest at 120f~, an acid rest (don't know the temp never done it), and a sacirifcation rest....not boiled....


my third step is a rest at 160-162 for alpha amylase....i do boil the running from the tun and add it back to raise the temp...but tannins are in the husks not the wort....
I was referring to pilsner Urquell who certainly boil their mash (at least a portion of it) three times during the mashing process. Zero tannins in that liquid nectar.
 

rsquared

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I was referring to pilsner Urquell who certainly boil their mash (at least a portion of it) three times during the mashing process. Zero tannins in that liquid nectar.
Decoction isn't boiling the mash itself, it's pulling off a portion of the wort, boiling that, then adding it back to the mash and thereby raising the overall temp of the mash. The grains themselves (where the tannins are) is never raised over 170.
 

day_trippr

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tannins? been a while, but isn't that the one that tastes like skunks ass, like heineken?
That long noted character of Heineken has always been compared to light-struck beer.

fwiw, the whole "mash out" paradigm is surely tied to the classic fly sparge technique which does entail a significant amount of time (takes me almost an hour at 1 quart per minute for 13.5 gallons to the kettle)...

Cheers!
 

bracconiere

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That long noted character of Heineken has always been compared to light-struck beer.
when people are learning to BJCP people...don't they serve it for reference? lol, i've always thought that was their selling point and why they have green bottles....
 

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I'm not sure about tanin extraction at high temps due to the fact that some of the best beer in the world is triple decocted (boiled three times). If that doesn't extract tanins I'm not sure hot batch sparging will do it either.
There are a couple of things to remember here (I also do decoctions on occasion). First, tannin extraction is most likely to happen during a sparge because of the pH. Tannin extraction is generally due to high temperatures AND a high pH. That can happen during sparging.

Decoctions boil the thickest part of the mash- when the mash pH is usually around 5.3-5.4 or so. No risk of tannin extraction when those factors are controlled.

Decoction isn't boiling the mash itself, it's pulling off a portion of the wort, boiling that, then adding it back to the mash and thereby raising the overall temp of the mash. The grains themselves (where the tannins are) is never raised over 170.
That's not so- the decoction boils the thickest part of the mash, with only enough liquid to boil. When you do a decoction mash out, however, you can then pull the liquid which would deactivate the enzymes. But again, the pH here is critical.
 

bracconiere

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Sure! When you pull the decoction, you take mostly grain with just enough liquid to be able to boil it.
am i misinterperting this? i don't know how i could seperate the malt from the wort in my mash tun, to 'just right'?


i usually raise my temps by draining how ever much wort out of the mash tun i need to get to my step and bring it to boil then stiring it back it.....not sure if this is something new i should try.

edit: i do love a malty beer, and if this doesn't cause tannin extraction, boiling the actual malt sounds like it might be a good thing...i just have bad memories of back when i thought i was supposed to sparge with boiling hot water...
 

bracconiere

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reading that...i might try heating my strike water to the right temp for 1/3 the grain bill...mash for 30 minutes, then bring it to a boil, let cool to strike temp for the other 2/3's....might be fun, Thanks!
 

day_trippr

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If one sets the mash and the sparge liquor chemistry so that the end-of-runnings pH stays above BELOW 5.6, tannin extraction will be minimized pretty much regardless of sparge liquor temperature...

Cheers!

[edited to correct my boo-boo ;)]
 
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bracconiere

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blame it on what you want, i blame the fact i'm drinking hard alcohol today, for my performance!

but i learned something.....just wanted to make that was the only thing new
 
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Vale71

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After that, if we sparge, we can sparge with ice cold water if we want to. Sparging with hot water (under 170 degrees) at that point has only one benefit- to help get the wort to a boil faster than using cold water.
You're forgetting lower viscosity and improved extraction (solubility is temperature dependent). ;)
 

Qhrumphf

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Hot sparging:

A) decreases time to boil
B) either increases efficiency or at least decreases runoff time to obtain the same efficiency.

These mostly matter in commercial operations where time is money and an extra 10 minutes on either side is labor costs and decreases is number of turns per day.

As far as mashout, with some tweaking you can set your mash/sparge process such that with a shorter mash even with a fly sparge you can continue conversion in the kettle and heat the kettle at the right time such that sparge water and kettle flame set your wort sugar composition where you want it, eliminating the need for mash out. I used to do 15 minute mashes years ago, where after a quick vorlauf my wort would keep converting in the kettle. Very system dependent to make it work though.

And tannin extraction is a trifecta- pH, gravity, AND temp, with temp arguably the least important of the three. pH is arguably the most important.

With decoction, and proper mash chemistry, pH and gravity never become an issue such that boiling the mash is just fine.

With sparging, the gravity of runnings drop, and unless you're brewing with zero alkalinity water (or otherwise acidified to neutralize) the pH will rise. These (especially when combined with temp) form tannin problems.

If you can control the temp and pH, you can then drive your runoff gravity down as a result. Conventional homebrew wisdom says stop sparging at 1.012. Sparging with 172F water and keeping runoff below 5.6, I routinely push runoff to 1.004. That's how you hit those mid 90s efficiencies (I hit 93-95% on moderate to even slightly high gravity brews on both my home and work systems).
 

bracconiere

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@olie is all this off-topic, or do you find it useful?

and @Qhrumphf you say temp doesn't matter, so if i add a couple cups of table sugar to last of my sparge water it'd be better then temp control?
 

Qhrumphf

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Not "doesn't matter" as much as "matters less". Even if you're sparging to 1.016 with decent pH, I'd think a grain bed way too hot might still have polyphenol problems.

It just means I don't panic if my water temp gets away from me and grainbed momentarily hits 173, especially early on in runoff.

And I don't sweat decoction where I know the temp isn't an issue.
 

bracconiere

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And I don't sweat decoction where I know the temp isn't an issue.

i hate to hijack but...for my idea of mash only 1/3 of my grain bill in full strike volume, beersmith tell me i'd have something around 1.024 OG....then boil it is that a high enough gravity? i'm not interested in brewing "the old way", but learning i can boil the malt, i want to try it in some fashion to see if i get more malty beer.....there was another thread about this, if you got any input i'll continue it there....with a link to this one....ph would probably be around 5.3
 

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I want to say (off the top of my head when drinking) that traditional decoctions are performed on "thick" mash that's thinner than performed by many US/UK brewers. Something like 1.5qt/lb. As long as you're at that ratio or thicker, only pulling a third of the grist, and either appropriate alkalinity for your grain bill or adjusted accordingly with acid, should be fine (especially if you do conversion rests on your decoction pulls).

The added benefit is that decoction takes the starch matrices and demolishes them, all but assuring maximal conversion.
 

bracconiere

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The added benefit is that decoction takes the starch matrices and demolishes them, all but assuring maximal conversion.

i've notice a second step at 162f bumped my effec from 83% to 90%, wasn't sure if it was alpha or starch gelling....

now to find that other thread, it went into lodo to get malty, this went from sparge temp, to outright boiling your mash....lol, fun times! :mug:
 

Yooper

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am i misinterperting this? i don't know how i could seperate the malt from the wort in my mash tun, to 'just right'?


i usually raise my temps by draining how ever much wort out of the mash tun i need to get to my step and bring it to boil then stiring it back it.....not sure if this is something new i should try.
You don't want to decoct with wort only, until mash out, as you don't want to denature the enzymes in the liquid.

Yooper, could you explain your procedure for the full volume mash you have been doing lately?
Thanks!
It's nothing special- just doing a full volume mash like the BIABers, but recirculating during the mash. Then running off after conversion (or 45-60 minutes) and putting it on to boil. I read years ago that this supposedly gives "higher quality wort", but I started doing it because it saves time without a sparge. The real impetus for this was my PID died in my HLT, and sparging with hot/warm water would be a pain.

The beer is great, and I haven't noticed any difference in the quality. I still maintain the same mash temperatures, mash/boil pH, etc.
 
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And tannin extraction is a trifecta- pH, gravity, AND temp, with temp arguably the least important of the three. pH is arguably the most important.

With decoction, and proper mash chemistry, pH and gravity never become an issue such that boiling the mash is just fine.

With sparging, the gravity of runnings drop, and unless you're brewing with zero alkalinity water (or otherwise acidified to neutralize) the pH will rise. These (especially when combined with temp) form tannin problems.

If you can control the temp and pH, you can then drive your runoff gravity down as a result. Conventional homebrew wisdom says stop sparging at 1.012. Sparging with 172F water and keeping runoff below 5.6, I routinely push runoff to 1.004. That's how you hit those mid 90s efficiencies (I hit 93-95% on moderate to even slightly high gravity brews on both my home and work systems).
The sparge water temperature still matters though, right? If the sparge water is 170F or less, is there a situation in which tannins would be extracted?
 
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