Temp lost to grain

CornyKegs 728
Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
slayer84

slayer84

Member
Joined
Jul 11, 2009
Messages
21
Reaction score
0
Location
Marion, IL
Hello fellow homebrewers,
I am going to be brewing my first all-grain batch soon and I was wondering how much temp is lost from the strike water to the grain? I will be mashing in a 10gal rubbermaid cooler which will be preheated.
 
Most of the temp lost is to the grain temp. There is a big difference between mashing in with grain that is 45F and grain that is 75F. You really need to experiment to find what the correct mash-in temperature is. Keep your grain temp the same, but record your strike water temp. After 1-2 brews you should be able to nail it, IF your grain temp is the same. When my grain temp is 50F, my strike water needs to be 176F to hit a 152F mash temp. If my grain is 68F, my strike water needs to be 172F to hit a 152F mash temp. YMMV, but the important thing is to record your temps for the next time you brew.
 
The easy way to get a handle on it for the first time would be to download the trial version of beersmith and use the strike water calculator. You won't need to buy it if you don't want to, but it can take some of the worry out of that first brewday in a lot of those aspects you won't fully understand yet. For my first AG brewday I downloaded it a week before my first AG brew, got accustomed to it and printed out the brewday schedule. It was a terrific hand-holder for me. It's a 30 day trial, so use it wisely if you don't think you will want to buy it. :)
 
+1 on Beersmith since it can also compensate for the heat characteristics of your MLT type. Make sure you preheat your cooler with water 12 deg hotter than strike temp for 10 min. Over the 10 min the water should drop to your strike temp. Stir if the temp is still too high. If you are too low, scoop some out, heat it to boiling in the microwave, and stir it back in.
 
There are several brewing software options. I use Beersmith and am very happy with it. Most have a trial period so you can download and try them out. Well worth the money.
 
Yea, sorry to say "go buy software" instead of giving a real answer, but I think its the best option. I let Beersmith do all my calculations so I can worry about more important things on brew day. I always hit my strike temp using beersmith. Just remember to preheat the mash tun.
 
Start at 12-13 degrees above your strike temp, With out the preheat. Then you will learn to adjust like they said. This is the way I learned. PS: I use a Heated mash tun, so the original temp might not make a big difference to me. I might give you problems in your cooler based mash tun.
 
Without doing all the calculations, you can take a guess at about 14F over your desired mash temp assuming the grain is room temp and your mash tun is preheated.

Example, mash temp of 155, stir the grain in when the water is 169F.

In order for the cooler not to steal too much heat, put the water in at about 175F (assuming it wasn't sitting in the garage or in a snow bank) and close the lid for 5 minutes. Open and stir until the temp drops to 169F.
 
I was loosing temp while I was doughing in, so I add strike water a bit higher than stated in Beersmith to allow time to stir. I'll stir until I reach my temp. I've also lost some temp when I stir half way through the mash. Any suggestions? Do most people stir the mash?
 
Blackhawkbrew said:
I was loosing temp while I was doughing in, so I add strike water a bit higher than stated in Beersmith to allow time to stir. I'll stir until I reach my temp. I've also lost some temp when I stir half way through the mash. Any suggestions? Do most people stir the mash?
Click to expand...

You don't need to stir the mash halfway through. (Some do, some don't) In winter, especially I would not do it if brewing in cold conditions.
 
Bobby_M said:
Without doing all the calculations, you can take a guess at about 14F over your desired mash temp assuming the grain is room temp and your mash tun is preheated.

Example, mash temp of 155, stir the grain in when the water is 169F.

In order for the cooler not to steal too much heat, put the water in at about 175F (assuming it wasn't sitting in the garage or in a snow bank) and close the lid for 5 minutes. Open and stir until the temp drops to 169F.
Click to expand...


This advice is spot on w/ my experience and worth repeating.
 
The temperature of the strike water will depend on the mash thickness as well as the grain temperature. With 60 F grains, 169F water gives me a mash temp of 152F. (I mash thicker than Bobby_M).
If you really want to calculate it yourself, I posted the following in another thread earlier today.

Specific heat of water is 1.0 cal / gram / degree C
Specific heat of malt is 0.4 cal / gram / degree C

Assume you have 5 Kg grain at 20 C that you need to mash at 66C with 6 L water.

You need to raise the temp of the grain by 46 C, so you will need 5 * 0.4 * 46 Kcal = 92 Kcal
Divide the 92 Kcal by 6 L = 15.3 to get the extra temperature of the strike water in C, so the required strike temp would be 66 + 15.3 = 81.3 C.

But it's much easier to use brewing software. I like Promash.

-a.
 
Assuming you are comfortable using a pocket calculator, Palmer's How to Brew has the formula to calculate your strike water temperature. It's really simple math and you could easily put it into a spreadsheet. I think any of the brewing software will have the tools you need for this as mentioned in above posts.
 
Catt22 said:
Assuming you are comfortable using a pocket calculator, Palmer's How to Brew has the formula to calculate your strike water temperature. It's really simple math and you could easily put it into a spreadsheet.
Click to expand...

So let's try it.

What is the strike temperature of 10 lb grain at 60F with 12.5 qt water to reach a mash temperature of 152.
From the Palmer formula
r = 1.25
T1 = 60
T2 = 152
From the formula [FONT=Verdana, Arial, Helvetica, sans-serif]Tw = (.2/r)(T2 - T1) + T2 (where Tw is the strike temperature)[/FONT]
Tw = (.2/1.25)(152 - 60) + 152
Tw = (0.16)(92) + 152
Tw = 14.16 + 152
Tw = 166.16
I will assume that this is right because when I checked his US formula against my calculations and Promash (with numbers that I regularly use), they are (as near as makes no difference) identical.
Now let's try converting to metric.
r = 1.25 * 1.183 / 0.454 = 3.286
T1 = 15.56
T2 = 66.67
Tw = (.41/3.286)(66.67 - 15.56) + 66.67
Tw = (0.126)(41.11) + 66.67
Tw = 5.180 + 66.67
Tw = 71.85 C
Tw = 161.33 F

I don't know about you, but I think there's a big difference between 161.33 F and 166.16 F

-a.

 
Blackhawkbrew said:
I was loosing temp while I was doughing in, so I add strike water a bit higher than stated in Beersmith to allow time to stir. I'll stir until I reach my temp. I've also lost some temp when I stir half way through the mash. Any suggestions? Do most people stir the mash?
Click to expand...



Before I had a decent understanding of what my preheating temp/time and strike temp should be, I would dough in 2 deg above my desired strike temp. It was common for me to lose 4 deg over the 60 min mash. Now, using the same cooler, I lose less than 2 deg over the 60 min mash.

The only reason I stir the mash is if the temp has crept up significantly after dough in.
 
ajf said:
So let's try it.

What is the strike temperature of 10 lb grain at 60F with 12.5 qt water to reach a mash temperature of 152.
From the Palmer formula
r = 1.25
T1 = 60
T2 = 152
From the formula [FONT=Verdana, Arial, Helvetica, sans-serif]Tw = (.2/r)(T2 - T1) + T2 (where Tw is the strike temperature)[/FONT]
Tw = (.2/1.25)(152 - 60) + 152
Tw = (0.16)(92) + 152
Tw = 14.16 + 152
Tw = 166.16
I will assume that this is right because when I checked his US formula against my calculations and Promash (with numbers that I regularly use), they are (as near as makes no difference) identical.
Now let's try converting to metric.
r = 1.25 * 1.183 / 0.454 = 3.286
T1 = 15.56
T2 = 66.67
Tw = (.41/3.286)(66.67 - 15.56) + 66.67
Tw = (0.126)(41.11) + 66.67
Tw = 5.180 + 66.67
Tw = 71.85 C
Tw = 161.33 F

I don't know about you, but I think there's a big difference between 161.33 F and 166.16 F

-a.

Click to expand...


I think the metric water/grain ratio should be 2.62, not 3.26

ie 1.25 qts/lb = 1.18 ltr/.45 k or 2.62 liter/k

Also the 0.2 constant needs to be converted to metric dimensions.

.2/1.25 = x/2.62 then x = .42

Using these corrected values we get:

(.42/2.62)(66.67-15.56)+66.67=74.86C

74.86 C = 166.75 F

Not precisely the same number, but fairly close. The Promash strike water calculator has both English and metric values. ie it shows 166.00 F & 74.44 C using our above numbers.
 
Aa + Bb = Cc

A=specific heat of grain (.5 x lbs of grain)
a=temperature of grain
B=Specific heat of strike water (1 x gallons of water)
b=temperature of strike water
C=specific heat of mash (A + B)
c=temperature of mash (your target temperature)

Solve for b and get your strike temperature.
=((((grain_lbs*0.05)+mash_water)*targ_mash_temp) - ((grain_lbs*0.05)*grain_temp))/mash_water

This assumes your mash tun is pre-heated... or you have to add another pair of variables. I don't know the specific heat of my cooler...
 
Yeah, it's tough to know where an answer should fall on the rule-of-thumb to rocket science scale. If you give a simple answer and then pepper in caveat, caveat, caveat, etc., it's not really simple anymore. I'll summarize it like this, either use this simple rule of thumb, or buy beersmith or beer tools pro, calibrate the software to your equipment, and use it to figure out your infusion temps.
 
Not all noobs are the same.

A noob can start at any point on the spectrum:
One end: using general, imprecise "rules" or "guidelines"
Middle: getting precision from software
Other end: doing all of the math yourself

I actually got into AG partly because I wanted to learn the math and have intimate control over the process. I was glad to have a choice, rather than being told I must start at the other end of the spectrum. It was intimidating, but totally worth it. I think my beer would be just as good without knowing the formulae... but I guess I'm more than a bit anal. I don't like surprises... maybe I need therapy.
 
In our quest for awesome homebrew, we can stive to do everything from scratch (including the math), or aim for simplicity. Some of us grow hops, roast our own grains, and propogate yeast... while others brew from pre-hopped extracts. Nothing wrong with either approach; it's just a matter of how badly you are infected with the DIY virus.
(Personally, I would make my own bottles if I could!)

When I was new to brewing, I was thankful that this forum had a mixture of the simple and the exhaustively complex. It gave me the ability to choose my path and find my own comfort level with the details.
 
apeltes said:
In our quest for awesome homebrew, we can stive to do everything from scratch (including the math), or aim for simplicity. Some of us grow hops, roast our own grains, and propogate yeast... while others brew from pre-hopped extracts. Nothing wrong with either approach; it's just a matter of how badly you are infected with the DIY virus.
(Personally, I would make my own bottles if I could!)

When I was new to brewing, I was thankful that this forum had a mixture of the simple and the exhaustively complex. It gave me the ability to choose my path and find my own comfort level with the details.
Click to expand...
Agreed...when I first started brewing, I didn't see any reason to leave the Mr Beer system, (ouch, that hurt). Then I didn't see any reason to do AG or harvest yeast. Saturday was my 2nd AG batch & my first using harvested yeast. :mug: The journey has been half the fun.
 

Similar threads

hotbeer
What if you bring the malts slowly to mash temp?
Replies
14
Views
1K
hotbeer
hotbeer
R
Wort Transformation Competition
Replies
3
Views
220
FloppyKnockers
FloppyKnockers
rmr9
Beta glucan rest in AiO
Replies
16
Views
771
IslandLizard
IslandLizard
W
875 watts enough for RIMS heat?
Replies
12
Views
945
doug293cz
doug293cz
iandanielursino
Lots of grain mush in the wort and scorching
Replies
4
Views
177
iandanielursino
iandanielursino
BrewSwag 300

Latest posts

Back
Top