Why do we sparge with hot water?

[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.

 

[chaps]

2) maltose is much more soluable in hot water so it can improve efficiency (or at least time)

number two is why I do a high temp sparge. Especially with all rice grain bills things get “sticky” and using hot water helps everything drain instead of possibly coagulating. As a GF brewer one of my goals is efficiency since we start at a disadvantage so anything that helps with that I’m all for.

 

[eric19312]

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.

I started out using hot tap water for both mash and sparge to save time heating water but somebody in here convinced me there are some safety issues to consider. Potential metal contaminants I believe.

 

[Gruel]

I'd make sure the hot tap water is safe for human consumption, independent of brewing usage.

 

[stamandster]

I mash-out from 168-170f, I use room temp water for fly-sparge. I consistently hit 80%+

 

[bobeer]

I only sparge with 180 degree F water so it'll get to a boil faster. I used to do it with straight tap water to save time but then realized it took much longer to get it to a boil that way. As already stated, if you keep and eye on the ph and gravity you should be able to stop it before you pull anything bad out. I usually stop the sparge at 1.010... Anything below that is tossed. No issues or off flavors.

and as for all the decoction talk.. I just did one a week or so ago. There's a great Brewing TV episode about how to do it if you look it up on YouTube and that is pretty much what i did...

I mashed in at blood temp then took 2/3's of the grist back out of the mlt, boiled it for 15 minutes, then added it back to the mlt to bring it up to the next rest temp. I did that 3 times and by the 3rd time it reached 150 degrees F. After that it was a regular brew day. I just bottled it a few days ago so we'll see how it turned out soon!