Water Amount Question

Hey Everyone,

I am busy contemplating my first AG batch and just wanted to make sure my calculations are correct on how much water I should have ready for mashing and sparging. The total grain bill on the recipe I am thinking about using is 11.5#, which means that I should use about 4.3 gallons for mashing (11.5 x 1.5 qt / 4) and 5.75 gallons for sparging (11.5 x 2 qt / 4). I am a little concerned because this seems like an awful lot of water for a 5 gallon batch ( I'm actually looking to collect 6 gallons with about 1/2 gallon boil off and 5.5 into the fermentor). Since I've never done AG I don't know how much liquid the grain will absorb, etc. so I wanted someone to tell me if I'm headed in the right direction. Thanks in advance.

You will likely loose more than .5 gallons to evaporation during the boiling process but it will take a few brews to get your rate. I loose at least 1 to 1.5 gallons depending on the day. I figure my absobtion rate at .13 gallons per pound. I add the absorbtion water at boiling to the mash to raise the temperature before running off.

When you determine how much your first runnings have been collected you can determine your 2nd runnings as they should be equal volumes. Naturally the grain will not absorb additional water on the sparge.

If you are using leaf hops they will absorb wort as well.

HuggerOrange said:

Hey Everyone,

I am busy contemplating my first AG batch and just wanted to make sure my calculations are correct on how much water I should have ready for mashing and sparging. The total grain bill on the recipe I am thinking about using is 11.5#, which means that I should use about 4.3 gallons for mashing (11.5 x 1.5 qt / 4) and 5.75 gallons for sparging (11.5 x 2 qt / 4). I am a little concerned because this seems like an awful lot of water for a 5 gallon batch ( I'm actually looking to collect 6 gallons with about 1/2 gallon boil off and 5.5 into the fermentor). Since I've never done AG I don't know how much liquid the grain will absorb, etc. so I wanted someone to tell me if I'm headed in the right direction. Thanks in advance.

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If you use 1.25 qt per LB of grain instead of 1.5 and use the same for sparge you will get around 6.5 gallons after grain absorbsion. The best way to get accurate recipes is to use a computer and Pro Mash or Beer Smith. It makes life easy for all grain brewers. It also gives you strike temperature. The Beer Smith program is under $20.00.

That does seem like alot of water. I batch sparge and would use 8.4 g total water to collect 7g of wort. In my system 0.12g/# is absorbed by the grain or lost to dead space in my mash/lauter tun. A one hour, slow roiling boil results in about 1g lost to evaporation so I end up with 6g in the pot, 5.25 g of crystal clear wort then ends up in my fermentor. You won't be able to put everything from your brew pot into your fermentor as there is a large amount of trub that settles out with all grain that isn't there with extract. Everyones system is different so your first batches will not be spot on but if you measure everything carefully (and calibrate your measuring vessels) you can dial it in. I would highly recommend brewing a lower gravity beer you like several times in a row quickly to do this.

GT

One point I would like to make is that if you sparge with equal amounts of water at 168 F and during the second sparge you should stir after adding the water and then wait for the sugars to come out of the grain (about 10 minutes) and then stir again and recirculate until running clear and then drain you will have done everything possible to extract sugars and should have good efficiency too.

WBC said:

One point I would like to make is that if you sparge with equal amounts of water at 168 F and during the second sparge you should stir after adding the water and then wait for the sugars to come out of the grain (about 10 minutes) and then stir again and recirculate until running clear and then drain you will have done everything possible to extract sugars and should have good efficiency too.

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So then you use batch sparging instead of continuous? I was going to follow the directions John Palmer gives on How to Brew, but I just read some stuff on batch sparging and was wondering if it's the way to go instead.

Read more here about batch sparging from the man that made it popular. I learned a lot from it.
http://hbd.org/cascade/dennybrew/

WBC said:

One point I would like to make is that if you sparge with equal amounts of water at 168 F and during the second sparge you should stir after adding the water and then wait for the sugars to come out of the grain (about 10 minutes) and then stir again and recirculate until running clear and then drain you will have done everything possible to extract sugars and should have good efficiency too.

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I'm getting some differences of opinion on this matter. Do you want the grain to stabilize at 168f (Bobby M posts this elsewhere) or do you want to add water that is 168f? If it's the former, than clearly you need to add hotter water to a 152f mash to sparge at 168. If that is in fact the case, how can we easily calculate the temperature of the first sparge infusion. Bobby M uses 180f for his first infusion. Is this standard procedure?

Thanks!

You want your mash to stabilize at 168 for that sparge. The temperature of your water depends on the temperature at the end of your last rest, the volume of your mash, and the volume of water you will add. I just let ProMash tell me what to do there.


TL

korndog said:

how can we easily calculate the temperature of the first sparge infusion.

Thanks!

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Try this
http://www.beertribe.com/gizmos/calcs/infusionb.php

TexLaw said:

You want your mash to stabilize at 168 for that sparge. The temperature of your water depends on the temperature at the end of your last rest, the volume of your mash, and the volume of water you will add. I just let ProMash tell me what to do there.
TL

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Thanks. So, you just use the strike water calculator in Pro-Mash. I get an initial infusion of 173f for my first batch sparge if the grains are at 152f. Does that sound close to what people are using in real life?

Thanks.

Yep. That sounds about right.


TL

korndog said:

Thanks. So, you just use the strike water calculator in Pro-Mash. I get an initial infusion of 173f for my first batch sparge if the grains are at 152f. Does that sound close to what people are using in real life?

Thanks.

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In my experience that is a little high. I would shoot for 168-169º. Try to get a good idea of your grain temperature.

Just checking ProMash real quick, I get an unfusion temperature of 171ºF for 11.25# of grain and ratio of 1.25 (14.06 qts), where the grain is at 72ºF and the thermal mass is 0.30 (based on a room temperature, 10 gallon, Rubbermaid cooler).


TL

I use the MashCalculator because i found Promash gave me too high of temps.It is just been my experience but it is far easier to cool the mash than to raise the temperature.

So far, ProMash has nailed infusion temperatures for me. It's a matter of getting that thermal mass set for your mashtun, though.


TL

TexLaw said:

So far, ProMash has nailed infusion temperatures for me. It's a matter of getting that thermal mass set for your mashtun, though.

TL

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Yeah, I am going to do that today. Found this in case anyone is interested. Thing is, if I plug .3 in for thermal mass and split the sparge infusion, I get about 180 for the first infusion, which corresponds to what Bobby M is using.

Q: What is the Thermal Mass of my mash tun, and how can I calculate it?
A: Thermal mass is the amount of heat your mash tun will absorb when you add the water. This can affect your calculations a bit when attempting to calculate your strike temperatures.

The default or "average" thermal mass of 0.30 will get you pretty close most of the time, but you can measure it yourself with the following procedure:

1. Go into ProMash and go into the Strike Temp calculator.
2. For Mash Tun Thermal Mass, Enter 0.
3. For Total Grain enter 0.00001 pounds. (It won't let you go any smaller - entering 0 will give you a division error.) This should make your water:grain ratio 120000:1.
4. For Total Water, enter 16.00 quarts.
5. For Desired Strike Temp, enter 170. (You can use any temperature but this will more accurately reflect actual mash temperatures.)
6. For Grain Temp, enter the current room temperature.
7. Heat 16 quarts (4 gallons) of water to 170 degrees and pour it quickly into the mash tun. Close the lid and seal it up, and let it sit for about 5 minutes.
8. Measure the temperature of the water in the mash tun.
9. Enter the temperature of the water in the mash tun in the "Desired Strike Temp" field in ProMash.
10. Now look at the "Initial Strike Water Temp Should Be" window. You will note that, with Thermal Mass set to 0, this number will be the same as the "Desired Strike Temp" field.
11. Now, in small (say 0.1 or smaller) increments, increase the Thermal Mass field until the "Initial Strike Water" field reads 170 (or whatever temperature you started with, if you didn't use 170 for some reason.).
12. Ta-da! Whatever the Thermal Mass field says is your mash tun's thermal mass!

I found the whole thermal thing in Promash to be quite confusing so I preheat the cooler to offset that setting. I got this information from reading a few forums where people had the same difficulty. If you strike at 180 degrees on 11.25 pounds of grain I would be very surprised if your mash is 152.

OK, now I'm a little confused. I just want to make sure in short that I want to do is:

1) Mash my 11.5# of grains at 152 with about 3.75 gal of water (using 1.3 qts per #) for an hour. This should leave me with about 2.25 gal after the grain absorbs some of the initial water. (used factor of .13 gal per # absorbtion rate)
2) Infuse the mash after an hour with 1 gal of 180 water to bring temp up to 168.
3) Let it sit for about 10 min. then completely drain. This should give me my first half of 6.5 gallons, or 3.25 of wort.
4) Add another 3.25 gal of water at about 180, mix with grains, let it sit for about 10 min., mix again and drain giving me my second half of the 6.5 boil volume of wort.
5) Complete as usual, drink heavily and hope I did everything correctly.

You seem to have it but to be clear, the initial strike water will be somewhere between 168-171 so that after all the grain is mixed you have the temperature at 152º. If the temp is a little high you can cool it down with ice as that works pretty well, its easier to cool the mash than to raise the temp without a lot more water. Make sense??
To make up for absobtion and to get to mashout temps add the hotter water at the end of 60 minutes. You can use 180 but I bet it won't rise to 168 but I actually don't believe that it is critical, just be in the 165 range will work. Keep track of your temperatures for the next brew.

Make sure you have some extra water to use just in case you run a bit short for some reason.

I appreciate the help - now I'm dying to do it and see how it goes !!! C'mon weekend !!!

HuggerOrange said:

I appreciate the help - now I'm dying to do it and see how it goes !!! C'mon weekend !!!

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You have a good and accurate thermometer don't you? That hung me up a couple of times. You will have a good time.

Blender said:

I found the whole thermal thing in Promash to be quite confusing so I preheat the cooler to offset that setting. I got this information from reading a few forums where people had the same difficulty. If you strike at 180 degrees on 11.25 pounds of grain I would be very surprised if your mash is 152.

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I think I unintentionally hijacked this thread. Thanks for your input. I will try a new thread for batch sparge temperature attainment.

Here's what my brewing spreadsheet tells me. Note that I am assuming a sacch. rest at 152 degrees and malt at about 70 degrees before dough-in. With a ratio of about 1.25 qt./lb, it's pretty safe to heat your strike water to 163 degrees. If you mash in a cooler, note that this does NOT take into account the heat you will lose there.



INPUTS:
Total grist weight (pounds) 11.5
Initial grain temperature (F) 70
Initial mashin ratio (qt./lb.) 1.25
Projected absorption rate (gallons/lb.) 0.15
Volume to kettle (gallons) 6.5


First rest target 152
Observed mash temp at end of first rest 152

Second rest target 168
Observed mash temp at end of second rest

Third rest target
Observed temp at end of third rest



OUTPUTS:
Dough-in volume (gallons) 3.59375
Dough-in temp (Fahrenheit) 162.9333333

Second infusion volume (gallons boiling water) 1.481060606
Third infusion volume (gallons boiling water) 0




Projected absorption (gallons) 1.725

Projected first runoff (no sparge) 3.349810606
Sparge water required (gallons) 3.150189394