Reliable strike water temperature calculation

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blackonblack

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I am running your standard 10 gallon Home Depot orange beverage cooler as a mash ton. for this Brew I'll be brewing about 12 pounds of grain what is the best way to calculate the strike temperature? Is there a reliable Calculator I can enter the mass of grains , temperature of grains and it automatically knows the temperature coefficient of the mash ton.

I have a laser temperature finder I can use to find a temperature of the cooler and grains and just entered the mass of water and mass of grains to figure out the strike temperature to get about 152 mash temperature
 
I use an app called Sparg Pal (free) and it has been very reliable. I'm sure any program like Beersmith et al will be capable. I generally expect a 12-15* drop in temps from the strike temp, and then I cool or heat as needed. It's not often I've had to adjust.


Sent from my iPhone using Home Brew
 
This one is solid when you plug in accurate parameters. This formula assumes a preheated mash tun, so you could put in water several degrees hotter than the formula gives you and wait for it to hit your calculated strike water temp. For easiest and quickest use, arrange this formula in an Excel spreadsheet.

W = (.2/R)(T2-T1)+T2

Where:
W = strike water temp in Fahrenheit
R = water to grist ratio in quarts/lb (i.e. 1.25 or 1.5)
T1 = temperature of your dry grain in Fahrenheit
T2 = desired mash temp in Fahrenheit
 
Using any of the various calculators I find I need a strike temp of 4°F higher than calculated to compensate for heat losses during the 3-4 minute initial doughing in/stir action. Then if I stir during the mash, I stand to lose another 2 degrees each time, so I leave it closed for an hour. I do peak after 10 minutes and stick a temp probe through the foil about half way down and measure several spots and it's usually within a half or one degree, which is as good as it gets with such a system.

That's for 5.5-6 gallon batches in a rectangular cooler, and the mash bed is covered with aluminium foil. Head space is typically about 40-60%.
 
I'm with blackonblack. It seems that a reasonably accurate formula that includes variables for initial tun temperature and surface area could be, ( or might have been), developed.
 
I'm with blackonblack. It seems that a reasonably accurate formula that includes variables for initial tun temperature and surface area could be, ( or might have been), developed.

If you know the temperature of the mash tun (deg F), weight of the mash tun (lbs), and thermal mass of the mash tun (BTU/lb*F) in addition to the malt temp, then you can very accurately calculate the strike water temp. But, really guys, just add 15-20F to the calculated value from the formula I provided above and wait for the temp to drop as the temperatures converge in your MLT. Then add your grain. This process hasn't failed me in 10 years.
 
I've had best luck aiming for a couple of degrees higher. It's always easy to add a few ice cubes to bring it down if you strike too high. It's much harder to heat it up.

But once you have the tun heated up, and the right temperature calculated, you shouldn't need to even do that. My problem is that I brew in extremely different temperatures throughout the year and my mash tun requires differing amounts of preheating. I'm not always patient enough to wait for it to preheat, so I sometimes aim high and adjust.
 
This one is solid when you plug in accurate parameters. This formula assumes a preheated mash tun, so you could put in water several degrees hotter than the formula gives you and wait for it to hit your calculated strike water temp. For easiest and quickest use, arrange this formula in an Excel spreadsheet.

W = (.2/R)(T2-T1)+T2

Where:
W = strike water temp in Fahrenheit
R = water to grist ratio in quarts/lb (i.e. 1.25 or 1.5)
T1 = temperature of your dry grain in Fahrenheit
T2 = desired mash temp in Fahrenheit

I detailed the theory behind this equation and how it is derived from a much larger equation on another forum. I have included a copy of that post below for those who want to know more about elementary thermodynamics as applied to brewing.

*** start copied posting ***

If you are mashing at around 1.25 quarts of water (strike liquor) per pound in a typical cooler setup, a quick rule of thumb is to mash-in with strike liquor that is approximately nineteen to twenty degrees Fahrenheit higher than the desired rest temperature. For example, with a strike liquor to grist ratio of 1.25 quarts for pound, mashing-in with 170F strike liquor should result in the mash coming to rest at around 150F to 151F.

Here's the math:

Twenty pounds of grain has approximately as much heat capacity (a.k.a. specific heat) as one gallon of water; therefore, a pound of grain has approximately as much heat capacity as 0.05 gallons of water (1 / 20 = 0.05) or 0.2 quarts of water (1 / 20 x 4 = 0.2).

strike_liquor_temperature = ((desired_strike_temperature x (0.2 x grist_weight_in_pounds + strike_liquor_volume_in_quarts)) - (0.2 x grist_weight_in_pounds x grist_temperature)) / strike_liquor_volume_in_quarts

What the equation shown above does is calculate the total specific heat of the mash with respect to N quarts of water. This value includes the specific heat of the grain at rest temperature. The pre-mash-in grain specific heat is subtracted from the total mash specific heat, and the difference is then divided by the strike liquor volume in quarts yielding the strike liquor temperature. The equation can be simplified to:

strike_liquor_temperature = (total_mash_specific_heat – grain_specific_heat_before_mash_in) / strike_liquor_volume_in_quarts

where

total_mash_specific_heat = desired_strike_temperature x (0.2 x grist_weight_in_pounds + strike_liquor_volume_in_quarts)

grain_specific_heat_before_mash_in = 0.2 x grist_weight_in_pounds x grist_temperature

Example:

grist_weight_in_pounds = 10
grist_temperature = 72
strike_liquor_volume_in_gallons = 12.125 (1.25 quarts per pound)
desired_strike_temperature = 151F

total_mash_specific_heat = 151 x (0.2 x 10 + 12.5) = 2189.5

grain_specific_heat_at_mash_in = (0.2 x 10 x 72) = 144

strike_liquor_temperature = (2189.5 - 144) / 12.5 = 163.64F

In practice, depending on how full your mash tun is after mash-in has been completed, it will take an additional 4 to 6 degree increase in the strike liquor temperature to hit your target mash temperature due to thermal losses to the cooler itself, which is why a good strike liquor temperature for a 151F mash is around 170F when using a hot liquor to grist ratio of 1.25 quarts per pound in a non-preheated cooler-based mash tun.

The equation shown below is mathematically derived from the equation shown above. It is based on a strike liquor volume to one pound of grist ratio. This ratio holds as we increase the weight of the grist; therefore, the result holds as we scale the grist.

strike_liquor_temperature = (.2 / hot_liquor_to_grist_ratio_in_quarts_per_pound) x (desired_strike_temperature - grist_temperature) + desired_strike_temperature

grist_temperature = 72
hot_liquor_to_grist_ration_in_quarts_per_pound = 1.25
desired_strike_temperature = 151F

strike_liquor_temperature = (.2 / 1.25) x (151 - 72) + 151 = 12.64 + 151 = 163.64F

The equation shown above is equivalent to the “Initial Infusion Equation” in John Palmer’s book. I merely used more descriptive variable names. John labels desired_mash_temperature “T2,” grain_temperature “T1,” and hot_liquor_to_grist_ratio_in_quarts_per_pound “r” in his equation.

http://www.howtobrew.com/section3/chapter16-3.html

John Palmer’s Initial Infusion Equation:
Strike Water Temperature Tw = (.2/r)(T2 - T1) + T2
where:
r = The ratio of water to grain in quarts per pound
T1 = The initial temperature (¡F) of the mash
T2 = The target temperature (¡F) of the mash
Tw = The actual temperature (¡F) of the infusion water

Let’s say that I was completely dumbfounded that the equation found in John’s book yielded the same answer as the more complex equation that I had been using for years. It then dawned on me that the equations had to be related, which meant the equation in John’s book had to be a very clever simplification of the equation that I had been using. I sat down with pencil and paper and performed the algebra necessary to transform the equation that I had been using into the one in John’s book. Here’s the math for those who into mind numbing things: :)

First off, we set grist_weight_in_pounds equal to 1, which allows us to rename strike_liquor_volume_in_quarts to hot_liquor_to_grist_ratio_in_quarts_per_pound because the strike liquor volume is for one pound of grain.

strike_liquor_temperature = (desired_strike_temperature x (0.2 x 1 + hot_liquor_to_grist_ratio_in_quarts_per_pound) - (0.2 x 1 x grain_temperature)) / hot_liquor_to_grist_ratio_in_quarts_per_pound

which simplifies to:

strike_liquor_temperature = (desired_strike_temperature x (0.2 + hot_liquor_to_grist_ratio_in_quarts_per_pound) - (0.2 x grain_temperature)) / hot_liquor_to_grist_ratio_in_quarts_per_pound

Next, we divide both terms in the expression (desired_strike_temperature x (0.2 + hot_liquor_to_grist_ratio_in_quarts_per_pound)) - (0.2 x grain_temperature)) by hot_liquor_to_grist_ration_in_quart_per_pound, yielding:

strike_liquor_temperature = desired_strike_temperature x (0.2 + hot_liquor_to_grist_ratio_in_quarts_per_pound) / hot_liquor_to_grist_ratio_in_quarts_per_pound - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound

Multiplying desired_strike_temperature through the expression (0.2 + hot_liquor_to_grist_ratio_in_quarts_per_pound) yields:

strike_liquor_temperature = (0.2 x desired_strike_temperature + desired_strike_temperature x hot_liquor_to_grist_ratio_in_quarts_per_pound) / hot_liquor_to_grist_ratio_in_quarts_per_pound - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound

Dividing each term in the expression (0.2 x desired_strike_temperature + desired_strike_temperature x hot_liquor_to_grist_ratio_in_quarts_per_pound) by hot_liquor_to_grist_ratio_in_quarts_per_pound yields:

strike_liquor_temperature = 2.0 x desired_strike_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound + desired_strike_temperature x hot_liquor_to_grist_ratio_in_quarts_per_pound / hot_liquor_to_grist_ratio_in_quarts_per_pound
- 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound

Which reduces to:

strike_liquor_temperature = 2.0 x desired_strike_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound + desired_strike_temperature - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound

Reordering the terms leaves use very close to the final form:

strike_liquor_temperature = 2.0 x desired_strike_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound + desired_strike_temperature

The expression 2.0 x desired_strike_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound can be reduced to (2.0 x desired_strike_temperature - 0.2 x grain_temperature) / hot_liquor_to_grist_ratio_in_quarts_per_pound, which, in turn, can be reduced to 2.0 x (desired_strike_temperature - grain_temperature) / hot_liquor_to_grist_ratio_in_quarts_per_pound, which yields the final equation:

strike_liquor_temperature = 2.0 x (desired_strike_temperature - grain_temperature) / hot_liquor_to_grist_ratio_in_quarts_per_pound + desired_strike_temperature

which can be reordered to:

strike_liquor_temperature = 2.0 / hot_liquor_to_grist_ratio_in_quarts_per_pound x (desired_strike_temperature - grain_temperature) + desired_strike_temperature

which is the equation in John's book

Like I said, the simplification is very clever.

*** end copied posting ***
 
I detailed the theory behind this equation and how it is derived from a much larger equation on another forum. I have included a copy of that post below for those who want to know more about elementary thermodynamics as applied to brewing.

*** start copied posting ***

If you are mashing at around 1.25 quarts of water (strike liquor) per pound in a typical cooler setup, a quick rule of thumb is to mash-in with strike liquor that is approximately nineteen to twenty degrees Fahrenheit higher than the desired rest temperature. For example, with a strike liquor to grist ratio of 1.25 quarts for pound, mashing-in with 170F strike liquor should result in the mash coming to rest at around 150F to 151F.

Here's the math:

Twenty pounds of grain has approximately as much heat capacity (a.k.a. specific heat) as one gallon of water; therefore, a pound of grain has approximately as much heat capacity as 0.05 gallons of water (1 / 20 = 0.05) or 0.2 quarts of water (1 / 20 x 4 = 0.2).

strike_liquor_temperature = ((desired_strike_temperature x (0.2 x grist_weight_in_pounds + strike_liquor_volume_in_quarts)) - (0.2 x grist_weight_in_pounds x grist_temperature)) / strike_liquor_volume_in_quarts

What the equation shown above does is calculate the total specific heat of the mash with respect to N quarts of water. This value includes the specific heat of the grain at rest temperature. The pre-mash-in grain specific heat is subtracted from the total mash specific heat, and the difference is then divided by the strike liquor volume in quarts yielding the strike liquor temperature. The equation can be simplified to:

strike_liquor_temperature = (total_mash_specific_heat – grain_specific_heat_before_mash_in) / strike_liquor_volume_in_quarts

where

total_mash_specific_heat = desired_strike_temperature x (0.2 x grist_weight_in_pounds + strike_liquor_volume_in_quarts)

grain_specific_heat_before_mash_in = 0.2 x grist_weight_in_pounds x grist_temperature

Example:

grist_weight_in_pounds = 10
grist_temperature = 72
strike_liquor_volume_in_gallons = 12.125 (1.25 quarts per pound)
desired_strike_temperature = 151F

total_mash_specific_heat = 151 x (0.2 x 10 + 12.5) = 2189.5

grain_specific_heat_at_mash_in = (0.2 x 10 x 72) = 144

strike_liquor_temperature = (2189.5 - 144) / 12.5 = 163.64F

In practice, depending on how full your mash tun is after mash-in has been completed, it will take an additional 4 to 6 degree increase in the strike liquor temperature to hit your target mash temperature due to thermal losses to the cooler itself, which is why a good strike liquor temperature for a 151F mash is around 170F when using a hot liquor to grist ratio of 1.25 quarts per pound in a non-preheated cooler-based mash tun.

The equation shown below is mathematically derived from the equation shown above. It is based on a strike liquor volume to one pound of grist ratio. This ratio holds as we increase the weight of the grist; therefore, the result holds as we scale the grist.

strike_liquor_temperature = (.2 / hot_liquor_to_grist_ratio_in_quarts_per_pound) x (desired_strike_temperature - grist_temperature) + desired_strike_temperature

grist_temperature = 72
hot_liquor_to_grist_ration_in_quarts_per_pound = 1.25
desired_strike_temperature = 151F

strike_liquor_temperature = (.2 / 1.25) x (151 - 72) + 151 = 12.64 + 151 = 163.64F

The equation shown above is equivalent to the “Initial Infusion Equation” in John Palmer’s book. I merely used more descriptive variable names. John labels desired_mash_temperature “T2,” grain_temperature “T1,” and hot_liquor_to_grist_ratio_in_quarts_per_pound “r” in his equation.

http://www.howtobrew.com/section3/chapter16-3.html

John Palmer’s Initial Infusion Equation:
Strike Water Temperature Tw = (.2/r)(T2 - T1) + T2
where:
r = The ratio of water to grain in quarts per pound
T1 = The initial temperature (¡F) of the mash
T2 = The target temperature (¡F) of the mash
Tw = The actual temperature (¡F) of the infusion water

Let’s say that I was completely dumbfounded that the equation found in John’s book yielded the same answer as the more complex equation that I had been using for years. It then dawned on me that the equations had to be related, which meant the equation in John’s book had to be a very clever simplification of the equation that I had been using. I sat down with pencil and paper and performed the algebra necessary to transform the equation that I had been using into the one in John’s book. Here’s the math for those who into mind numbing things: :)

First off, we set grist_weight_in_pounds equal to 1, which allows us to rename strike_liquor_volume_in_quarts to hot_liquor_to_grist_ratio_in_quarts_per_pound because the strike liquor volume is for one pound of grain.

strike_liquor_temperature = (desired_strike_temperature x (0.2 x 1 + hot_liquor_to_grist_ratio_in_quarts_per_pound) - (0.2 x 1 x grain_temperature)) / hot_liquor_to_grist_ratio_in_quarts_per_pound

which simplifies to:

strike_liquor_temperature = (desired_strike_temperature x (0.2 + hot_liquor_to_grist_ratio_in_quarts_per_pound) - (0.2 x grain_temperature)) / hot_liquor_to_grist_ratio_in_quarts_per_pound

Next, we divide both terms in the expression (desired_strike_temperature x (0.2 + hot_liquor_to_grist_ratio_in_quarts_per_pound)) - (0.2 x grain_temperature)) by hot_liquor_to_grist_ration_in_quart_per_pound, yielding:

strike_liquor_temperature = desired_strike_temperature x (0.2 + hot_liquor_to_grist_ratio_in_quarts_per_pound) / hot_liquor_to_grist_ratio_in_quarts_per_pound - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound

Multiplying desired_strike_temperature through the expression (0.2 + hot_liquor_to_grist_ratio_in_quarts_per_pound) yields:

strike_liquor_temperature = (0.2 x desired_strike_temperature + desired_strike_temperature x hot_liquor_to_grist_ratio_in_quarts_per_pound) / hot_liquor_to_grist_ratio_in_quarts_per_pound - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound

Dividing each term in the expression (0.2 x desired_strike_temperature + desired_strike_temperature x hot_liquor_to_grist_ratio_in_quarts_per_pound) by hot_liquor_to_grist_ratio_in_quarts_per_pound yields:

strike_liquor_temperature = 0.2 x desired_strike_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound + desired_strike_temperature x hot_liquor_to_grist_ratio_in_quarts_per_pound / hot_liquor_to_grist_ratio_in_quarts_per_pound
- 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound

Which reduces to:

strike_liquor_temperature = 0.2 x desired_strike_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound + desired_strike_temperature - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound

Reordering the terms leaves use very close to the final form:

strike_liquor_temperature = 0.2 x desired_strike_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound + desired_strike_temperature

The expression 0.2 x desired_strike_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound - 0.2 x grain_temperature / hot_liquor_to_grist_ratio_in_quarts_per_pound can be reduced to (0.2 x desired_strike_temperature - 0.2 x grain_temperature) / hot_liquor_to_grist_ratio_in_quarts_per_pound, which, in turn, can be reduced to 0.2 x (desired_strike_temperature - grain_temperature) / hot_liquor_to_grist_ratio_in_quarts_per_pound, which yields the final equation:

strike_liquor_temperature = 0.2 x (desired_strike_temperature - grain_temperature) / hot_liquor_to_grist_ratio_in_quarts_per_pound + desired_strike_temperature

which can be reordered to:

strike_liquor_temperature = 0.2 / hot_liquor_to_grist_ratio_in_quarts_per_pound x (desired_strike_temperature - grain_temperature) + desired_strike_temperature

which is the equation in John's book

Like I said, the simplification is very clever.

*** end copied posting ***


I noticed that I made a transcription error in my original posting. I wrote 2.0 instead of 0.2, and the error was carried forward for the remainder of the posting. I would have liked to have been able to edit the original posting, but that feature is disabled after a period of time on this forum. The values shown in bold have been changed from 2.0 to 0.2. I am sorry if this error has caused confusion.
 
Generic equation is:
Mwater*CpWater*deltaTwater=Mgrains*Cpgrains*deltaTgrains
Where M=mass
Cp= heat capacity

Delta goes to:
Mwater*Cpwater*(Twater-Tmash)=Mgrains*Cpgrains*(Tmash-Tgrains)

Solving for Twater (strike temp):
Mgrains*Cpgrains*(Tmash-Tgrains)/(Mwater*Cpwater)+Tmash=Twater

Adding in Equipment Loss:
Mgrains*Cpgrains*(Tmash-Tgrains)/(Mwater*Cpwater)+Tmash+Equipment Loss=Twater

Heat Capacity of water=1
Heat Capacity of Grains=0.3822

For my 10 gallon igloo cooler preheated I add about 2%, or in most cases about 3 degrees.
 
Ok so I'm preparing to try my first AG RECIPE. Im having trouble figuring out my strike temp. Most calculators I have used tell me to get a mash at 153 il need a strike temp of 161-163 does that sound right?? I feel like that is a really low strike temp.. Should i just add 7 or 8 degrees to the 161 my app gives me and see what happens? I'm not planning on preheating my tun. It is a 48 qt rectangle cooler with a homemade false bottom made from copper tubing. Planning to batch sparge.
The app I'm using is called (calculate beer) its free for android. I must have watched every YouTube video and read 30 articles pertaining to AG, mashing, strike and sparge temps, grain bills hops, pots, coolers ECT.. I just need a little guidence.. It doesn't have to be perfect just in the ball park of 153.
Thank you for your time.

Here's the water requirements and recipe all copied off brewers friend let me know if you need any other info or have any modifications you feel I should make to this recipe to make things go smooth for my first try.

Water
Gallons/Quarts
Total mash water needed 8.41 33.7
Strike water volume at mash thickness of 1.5 qt/lb 3.38 13.5
Remaining sparge water volume 5.04 20.2
Grain absorption losses -1.13 -4.5
Mash Lauter Tun dead space -0.25 -1
Amount going into kettle 7.04 28.2
Boil off losses -1.5 -6
Hops absorption losses -0.04 -0.2
Amount going into fermentor 5.5 22
Total: 8.41 33.7


And here is the recipe

HOME BREW RECIPE:
Title: Easy Blonde Ale

Brew Method: All Grain
Style Name: Blonde Ale
Boil Time: 60 min
Batch Size: 5.5 gallons (fermentor volume)
Boil Size: 7.5 gallons
Boil Gravity: 1.033
Efficiency: 75% (brew house)


STATS:
Original Gravity: 1.045
Final Gravity: 1.011
ABV (standard): 4.48%
IBU (tinseth): 22.6
SRM (morey): 4.15

FERMENTABLES:
8 lb - American - Pale 2-Row (88.9%)
1 lb - American - Caramel / Crystal 10L (11.1%)

HOPS:
0.5 oz - Cascade, Type: Pellet, AA: 7, Use: Boil for 60 min, IBU: 14.08
0.5 oz - Cascade, Type: Pellet, AA: 7, Use: Boil for 20 min, IBU: 8.53

MASH GUIDELINES:
1) Infusion, Temp: 153 F, Time: 60 min
Starting Mash Thickness: 1.5 qt/lb

YEAST:
Wyeast - American Ale 1056
Starter: No
Form: Liquid
Attenuation (avg): 75%
Flocculation: Med-Low
Optimum Temp: 60 - 72 F
Fermentation Temp: 64 F
Pitch Rate: 2.0 (M cells / ml / deg P)


 
Last edited:
161-163 for a 153 mash sounds about right if the mash tun is preheated. That being said, I think you're thinking is right in going to something like 170 or 173 and waiting for the temp to drop to 162 before doughing in.

Its much easier to cool down the water once it's in your mash tun than to make it hotter.
 
161-163 for a 153 mash sounds about right if the mash tun is preheated. That being said, I think you're thinking is right in going to something like 170 or 173 and waiting for the temp to drop to 162 before doughing in.

Its much easier to cool down the water once it's in your mash tun than to make it hotter.
Thank you i just wanted to make sure I was heading in the right direction. The fella at my LHBS/hardware store doesn't really mess with AG so he doesn't really have much helpful advice.

Again I really appreciate you reading my post and giving me your 2 cents. I'll let you know how things went in a few weeks.
 
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