Why do we sparge with hot water?

[Vale71]

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]

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]

@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]

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]

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

 

[Qhrumphf]

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]

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!

 

[OakIslandBrewery]

Yooper, could you explain your procedure for the full volume mash you have been doing lately?
Thanks!

 

[Yooper]

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

https://www.google.com/search?client=firefox-b-1-d&q=decoction+def
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.

 

[thefigure5]

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?

 

[Davidio]

I use 180 degree water for a couple reasons.

1) It helps attract those sugar molecules from the grain. Remember, sparging is an osmotic procedure. You are not "rinsing" the sugar, you are coaxing the maltose to move from a higher concentration liquid to a lower one. and the hot water assists. If you use water in the 150-170 range, you may be leaving valuable sugars behind and thus to get them all you have an unmanageable volume of wort to boil down.

2) The risk of leaching tannins or fatty acids is perhaps higher by a small amount, but by the time that water makes its way into the mash, the temp will drop. Thusly, that argument does not hold water. Unless you are using a RIMS system, I wouldn't worry about that.

You definitely don't want you mash temp to drop below 150.

 

[bracconiere]

You don't want to decoct with wort only, until mash out, as you don't want to denature the enzymes in the liquid.

it's what i've always done...get about 88-90% effec....or 10 gallons of wort into fermenter at 1.067-68, with 20 lb's of malt?

 

[Spartan1979]

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.

If that's correct, I've been decocting incorrectly except for the mashout step. Usually one pulls the thickest part of the mash to decoct.

 

[bracconiere]

i'm still really at a loss at "thickest part" thing.....my mash isn't thicker or thinner anywhere.....is because you're supposed to use to seperate mash tuns? and one's thicker then the other?

 

[rsquared]

If that's correct, I've been decocting incorrectly except for the mashout step. Usually one pulls the thickest part of the mash to decoct.

Yeah, my bad...someone else also corrected my misunderstanding already. I should know better than to speak on things I don't actually have experience with.

 

[BigEd]

i'm still really at a loss at "thickest part" thing.....my mash isn't thicker or thinner anywhere.....is because you're supposed to use to seperate mash tuns? and one's thicker then the other?

When you do a decoction pull, the removed mash portion is strained to let much of the liquid remain behind in the mash. That's the thicker part. You want as little of the liquid to be subjected to boiling because it contains most of the enzyme content in solution. Preserving those enzymes from being denatured by the boiling temperature allows their work of conversion to continue in the main mash.

 

[bracconiere]

When you do a decoction pull, the removed mash portion is strained to let much of the liquid remain behind in the mash. That's the thicker part. You want as little of the liquid to be subjected to boiling because it contains most of the enzyme content in solution. Preserving those enzymes from being denatured by the boiling temperature allows their work of conversion to continue in the main mash.

maybe it's already mostly converted when i do it, but i've done it that way for years.....i let it sit at 150f for 30 min, then drain enough from the tun to boil to get the mash temp up to 162f....then wait another 30 minutes, then sparge with 168f water.....seems to work good for me, before i started doing the second step at 162f i only got 83% effec....(have wondered if it's better geling or alpha)

 

[bracconiere]

as far as the not wanting to boil the wort for enzymes, being that that's what i've done and it converts just fine, it may be like the tannin myth?

i might try and do it with a protein rest and see if it still converts or not?


(question: have you ever actually tried, or saying what you've heard like the tannin myth? )

 

[BigEd]

as far as the not wanting to boil the wort for enzymes, being that that's what i've done and it converts just fine, it may be like the tannin myth?

i might try and do it with a protein rest and see if it still converts or not?

You are starting your mash at the main conversion temperature. After 30 minutes most conversion will already have been completed. A typical, and certainly a traditional decoction mash is started a lower temperatures well before starch conversion has been completed. Apples and oranges here. Tannins aren't a myth, most homebrewers don't seem to understand the precursor effects and take off on a tangent with partial knowledge of the process.

 

[Davidio]

If that's correct, I've been decocting incorrectly except for the mashout step. Usually one pulls the thickest part of the mash to decoct.

Decoction was used back in the days when there were no thermometers and, by trial and error, brewers learned how much of a mash should be taken in order to, when added back to the main mash, get the best results overall. Back then there were acid rests, protein rests and sugar rests thus the need for a triple decoction. That was because the malt they used was not fully modified. The acrospire was not developed to the point it is today and they need this treatment to keep the beer from being hazy or spoiling. This didn't matter whether you brewing a light or dark beer.

One of the benefits of decoction was to break down those components as well as to produce the maillard reaction that deepened the flavor of the finished beer.

The difference between a "thick" part and a "thin" part of the mash is simply the ratio of liquid to grain that is in that portion. No decoction is never boiled until that portion has undergone a sugar rest, whether the portion was pulled during the acid rest or the protein rest. The reaction occurs to the wort, not the grain.

True the enzymes are mostly contained in the wort, but some are there in the grain as well.

I'd recommend taking a thin portion, being careful to leave enough wort to convert the starches that are left to convert remaining starch to sugar.

Remember to continually stir the decoction until boil begins to prevent scorching.

 

[bracconiere]

Tannins aren't a myth, most homebrewers don't seem to understand the precursor effects and take off on a tangent with partial knowledge of the process.

i know there not a myth, i was being hyperbolic....i had a problem with them before. now i know less then 5.6, which i already knew...but now thanks to this thread, i know gravity matters more then temp, and temp isn't that big a deal, with the other two factors.....and i like the idea of bring some of the mash to a boil kernels and all, going to try for my next brew....(any idea how to turn a pressure cooker into a double boiler so i don't have stand there stiring for an 1:30?, lol)edit(thanks for the idea! i'll use a veg steamer in the bottom so that the actual malt doesn't touch the bottom, no need for double boiler )


edit: damn, now i want to try and pressure cook it!

 

[Vale71]

as far as the not wanting to boil the wort for enzymes, being that that's what i've done and it converts just fine, it may be like the tannin myth?
)

More like a leftover from olden times when malt had maybe one third of the diastatic power of modern malts.

Nowadays commercial breweries that still decoct pull a mash that has the same thickness as the main mash as you cannot do it any other way when moving large quantities of liquid with centrifugal pumps. For the final step a thin mash is indeed pulled by stopping the paddles and letting the suspended grain settle to the bottom of the mash tun forming a filter bed. A thin mash is then slowly pumped from the mash tun to the boil kettle for the final decoction and then back for mashout.

With modern malts there is really no reason to pull a thick mash and risk scorching. Plus we have the advantage of the modern thermometer which allows us to let the pulled mash rest at saccharification temperature before boiling it.

 

[BigEd]

i know there not a myth, i was being hyperbolic....i had a problem with them before. now i know less then 5.6, which i already knew...but now thanks to this thread, i know gravity matters more then temp, and temp isn't that big a deal, with the other two factors.....and i like the idea of bring some of the mash to a boil kernels and all, going to try for my next brew....(any idea how to turn a pressure cooker into a double boiler so i don't have stand there stiring for an 1:30?, lol)edit(thanks for the idea! i'll use a veg steamer in the bottom so that the actual malt doesn't touch the bottom, no need for double boiler )


edit: damn, now i want to try and pressure cook it!

Yooper explained the tannin thing very nicely in an earlier reply. Many homebrewers get hung up on the temperature thing but it's only part of the equation.

 

[bracconiere]

Yooper explained the tannin thing very nicely in an earlier reply. Many homebrewers get hung up on the temperature thing but it's only part of the equation.

i liked @Qhrumphf 's info better!

More like a leftover from olden times when malt had maybe one third of the diastatic power of modern malts.

damn, being i do it with homemalt...i'm a better maltster then mediveal brewers! thanks! but with my knowledge of brewing, i strike in at protein rest, and thanks to my handy-dandy INSTANT read thermometer, gently heat up to sacirfication temp, put in mash tun, then bump up to the 162f step.....but i can usually skip the protein rest....

(i do not know where/how the knowledge to let the acrospires get to 100% length came from though)

 

[Qhrumphf]

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?

If the pH gets to high, water temp isn't gonna matter much.

 

[Granite03]

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

I gave up sparging with 170F water a few years ago and now view it as an unnecessary step. I now sparge with hot tap water and haven't noticed a difference.

 

[Yooper]

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?

Yes, in two cases. One, sparging with alkaline sparge water and/or oversparging.

 

[catalanotte]

You don't want to decoct with wort only, until mash out, as you don't want to denature the enzymes in the liquid.

I have a volume limited mash tun (10g cooler) so this is the only way I can get the grain bed up to ~168. I’ll pull 2-3 gal of wort only and boil, then return to mash. I have also seen a nice efficiency bump with this step. Many of my beer have ended up a couple SRM points darker that planned, I suspect this step may have something to do with this.

 

[RM-MN]

I have a volume limited mash tun (10g cooler) so this is the only way I can get the grain bed up to ~168. I’ll pull 2-3 gal of wort only and boil, then return to mash. I have also seen a nice efficiency bump with this step. Many of my beer have ended up a couple SRM points darker that planned, I suspect this step may have something to do with this.

You might get the same efficiency bump by mashing longer and avoid the darkening.

 

[catalanotte]

You might get the same efficiency bump by mashing longer and avoid the darkening.

Thanks. What are your thoughts on how this impacts conversion efficiency vs sparge efficiency? I see a longer mash improving conversion efficiency and potentially increasing fermantability (temperature dependent), but a good mash out rest helping to improve the sparge efficiency, without adding fermentabiltiy. I am seeing acceptable efficiency (93% conversion and 92 % sparge) and am using this technique more to try and manage fermentabiltiy. I actually avoid a mash out step for beers with a desired high attenuation. Might try an iodine test in the future to see where I really stand on conversion.

The color issue is addressed in the recipe building with a lower calculated SRM than actually desired.