Batch Sparge Water Temperature Calculation

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HopRodGR

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Hi All,

I'm looking for the equation that calculates the temperature you should heat your batch sparge water to, based on the temperature of the soaked grain remaining after the first runnings are drained.

I'm currently attempting to put together an Excel spreadsheet that will give me a table of temperatures, since predicting what temperature the grain will be after draining the mash is difficult to predict. Having a range of values allows me to easily reference the right sparge water temperature to heat to.

My initial thought is calculating the weight of the grain, which would be the dry weight plus the weight of the water absorbed, against the weight of the sparge water, factoring in temperatures, would get me there. However, this doesn't take into account the density differences in a pile of wet grain vs. just water.

Here is my simple calc:

(Weight of wet grain/(Weight of grain + sparge water))*Grain Temp + (Weight of Sparge Water/(Weight of grain + sparge water))*Sparge Water Temp = Temperature of Batch Sparge.

Since the weight of water is 8.35lb/gal and the generally accepted absorption of grain is 0.13gal/lb, it should be easy enough to plug these values in.

Have I over-simplified and missed an important variable or this or does this look right?
 
The grain temp at mash out should be whatever your mash temp was. There are loads of calculators on the interwebs to do this. Hang on, I'll go find one.
 
My formula looks like this, FWIW:

=(MashT1+0.192*(MashT1-GrainT)/StrikePerLb)
 
Thanks for the replies. I've found that when I drain my runnings, the remaining mash is almost never the same temp as the one I actually mashed at. Usually, it's lower, and when I heat my sparge water to the temp an online calculator calls for, I end up with a sparge temp that is too low, often in the low 160's. How to Brew has a mash in formula, but not one to account for grain that has absorbed water. With there being so many calculators online, I was looking to build my own model to give me a wide range if what I initially plug in for ending mash temp turns out to be wrong.
 
oakbarn said:
Did you ever make your xls. I have not found a good formula for the mash in temp with a set volume

I have an xls that I use for the entire recipe/process. I can share on drive if you wish
 
This is the TRUTH! I heat my batch sparge water to 190F for every brew. Kai has shown that you can even slarge with room temp water with no effect on beer quality or efficiency. It just doesn't matter.

That's really interesting, since as a newer homebrewer it is drilled into your head to get your sparge water as close as you can to 170 without going over, when it appears, that is really unnecessary. I generally like reading Kai's stuff so I'll have to dig up his write up on this too.
 
Thanks for the replies. I've found that when I drain my runnings, the remaining mash is almost never the same temp as the one I actually mashed at. Usually, it's lower, and when I heat my sparge water to the temp an online calculator calls for, I end up with a sparge temp that is too low, often in the low 160's. How to Brew has a mash in formula, but not one to account for grain that has absorbed water. With there being so many calculators online, I was looking to build my own model to give me a wide range if what I initially plug in for ending mash temp turns out to be wrong.

Tastybrew has two calculators that I have been using in combination.

One for Infusion Masing and one for Sparging.

I also used some the calculations I found on the web and maybe Palmers book for the absorbtion factor...

I found that Tastybrew Sparge Calculator was just a "point" off with what I did by hand so I have been using that since. (I figured 1/10 of a gallon was close enough.

Good luck,

DPB
 
This is the TRUTH! I heat my batch sparge water to 190F for every brew. Kai has shown that you can even slarge with room temp water with no effect on beer quality or efficiency. It just doesn't matter.

I wish more people heeded this, since it came from numerous experiments and has been backed up with real-world results. It seems there are so many brewing superstitions out there...
 
That's really interesting, since as a newer homebrewer it is drilled into your head to get your sparge water as close as you can to 170 without going over, when it appears, that is really unnecessary. I generally like reading Kai's stuff so I'll have to dig up his write up on this too.

The truth is that pH is what you need to worry about during the sparge, not water temp. If you couldn't go over 170, you couldn't do decoction mashes, where you boil the grain. It works becasue the pH is low.
 
I wish more people heeded this, since it came from numerous experiments and has been backed up with real-world results. It seems there are so many brewing superstitions out there...

I've brewed over 400 batches and won numerous awards using that technique. That's enough proof for me!
 
I've brewed over 400 batches and won numerous awards using that technique. That's enough proof for me!

And should be for others, too. I for one am appreciative of your experience and have adopted your sparging methods to a tee. I do the same strike and sparge additions (mashing thinner, doing just one sparge addition, no mashout) and I don't worry much about sparge temp. The only reason I heat it to a higher temp is to get boil going faster.
 
The truth is that pH is what you need to worry about during the sparge, not water temp. If you couldn't go over 170, you couldn't do decoction mashes, where you boil the grain. It works becasue the pH is low.

Denny, I just want to clarify what you are saying so I am sure I am understanding correctly. I understand the pH concept as it relates to decoction, though isn't the thickness of the decocted portion part of what keeps the pH low enough to nullify tannin extraction?

Building on that, assuming I treat my sparge water to keep the pH down (I use lactic acid currently), is there any reason to be concerned about topping that magic 170 degree number that gets thrown around?
 
Denny, I just want to clarify what you are saying so I am sure I am understanding correctly. I understand the pH concept as it relates to decoction, though isn't the thickness of the decocted portion part of what keeps the pH low enough to nullify tannin extraction?

Building on that, assuming I treat my sparge water to keep the pH down (I use lactic acid currently), is there any reason to be concerned about topping that magic 170 degree number that gets thrown around?

Nope. Temp AND PH are the two factors for tannins. That's why he mentioned it only matters for sparging, when the wort is diluted.
 
Nope. Temp AND PH are the two factors for tannins. That's why he mentioned it only matters for sparging, when the wort is diluted.

That's always been my understanding too. That's why I'm following up on this quote from him from post #13...

"The truth is that pH is what you need to worry about during the sparge, not water temp"
 
That's really interesting, since as a newer homebrewer it is drilled into your head to get your sparge water as close as you can to 170 without going over, when it appears, that is really unnecessary. I generally like reading Kai's stuff so I'll have to dig up his write up on this too.

Cheers from GR :mug:

I also just started homebrewing and always went with 180 degree sparge water.
 
That's always been my understanding too. That's why I'm following up on this quote from him from post #13...

"The truth is that pH is what you need to worry about during the sparge, not water temp"

Well, he means that if you dilute too much you can get tannins, yes...but by the same token he and Kai have proven that you can sparge with cooler water and that would eliminate all possibilities.
 
WTF man. The other day, I had my mash at 152*F, and my sparge water at 175*F. So, I added 1.5gal "mash out" water (sort of) to my mash tun, stirred, rested for 5 mins, then took a temp reading - only to find 147*F!

Okay, fine, whatever, I drained my first runnings (which should leave behind a 147*F grain bed, amirite?), and poured in the remaining 3.5 gal of 175*F water (I re-checked the temp to be sure!). Stirred, closed lid for 5m to let the grain settle, then checked my temp - My sparge was even lower! 145*F!

Sparging is not my friend. No sir.
 
Fact is, its not crucial. I use equal parts strike and sparge water for my brews. I do not add any sparge water prior to first runoff. I then add sparge water in one big addition, stir, vorlauf, and run off slowly. All this time my kettle is heating and FWH are in.

This is how Denny does it and that's good enough for me!

There are no "rests" after I add sparge water, either. Just stirring, then vorlauf.
 
Denny, I just want to clarify what you are saying so I am sure I am understanding correctly. I understand the pH concept as it relates to decoction, though isn't the thickness of the decocted portion part of what keeps the pH low enough to nullify tannin extraction?

Building on that, assuming I treat my sparge water to keep the pH down (I use lactic acid currently), is there any reason to be concerned about topping that magic 170 degree number that gets thrown around?

I don't think the thickness of the decoction really matters. The pH of the whole mash is what counts.

As long as your pH is below 6, there should be no problem even using boiling water to sparge. At least, my own experience is that there is no problem.
 
That's always been my understanding too. That's why I'm following up on this quote from him from post #13...

"The truth is that pH is what you need to worry about during the sparge, not water temp"

Which means "I assume you've checked your pH and it's good, so water temp should not be an issue".
 
Well, he means that if you dilute too much you can get tannins, yes...but by the same token he and Kai have proven that you can sparge with cooler water and that would eliminate all possibilities.

Keep in mind that my experience is based on batch sparging, where you almost never see pH rise during the sparge. It could be totally different for fly sparging.
 
Keep in mind that my experience is based on batch sparging, where you almost never see pH rise during the sparge. It could be totally different for fly sparging.

Well, guys that mash pretty thick and sparge really thin with a lot of water...they're pretty diluted but still probably not as much as the tail-end of a fly-sparge.
 
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