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Strike Water Calculation

S

Streb

Greetings,

I've been trying to figure out a way to adjust the strike water temperature so that it takes in consideration the temperature in my MLT.  I store my grain inside the house so it is usually fairly warm, and I store my MLT outside where the temperature varies greatly.

For example, I'll be brewing today and my MLT (A 15 gallon cooler) will be about 35 degrees and my grain will be about 70 degrees.   I can't find anyplace in the program to take into account the MLT temps to make an accurate strike water temp.  How would I go about doing this?  Do I have to heat my MLT to the same temperature as my grain or am I missing something in the program?

Thanks in advance,
Rob
 
I'm not the program author, but here's roughly the steps you have to take...

1) Set the specific heat, volume, and mass of your mash tun. This is done in the Equipment Setup. Instructions are located here.

2) Tell the program the temperature of your mash tun and grain... you might need to fudge a little if the temps of each are a little different. This is done in the Mash Profile setup. Instructions are located here.

3) Tell the program to "Adjust Temp for Equipment"... you do this in the recipe view, down near the Mash Profile. Instructions are located here, toward the bottom of the page.

That should cover it. Brad (the author) will jump in and correct me if I've got it all messed up.
 
Thanks for the reply, I really appreciate it.  However, I have gone through those steps and my equipment is setup.  There is not anyplace that I can find that will let me set my mash tun actual temperature.  The mash tun specific heat setting seems to directly correspond to the mash tun material and doesn't seem like it wants a mash tun temperature.  If I'm supposed to add a temperature here, I don't understand it.

It appears to me that the program is assuming that the grain and mash tun are the same temperature.  

That isn't a big deal in the fall or spring, but in the winter, there could be variances of 50 or 60 degrees since my grain and MLT are stored indoors and outdoors.  This  will require a lot of playing with strike water additons of hot water and cold water to bring to the right temp and would throw off the water to grain ratio.
 
It appears to me that the program is assuming that the grain and mash tun are the same temperature.
I think that this is the case. You set the tun/grain temperature when you edit a Mash Profile. Say you pick a medium body single infusion mash with no mash out... if you double click on it, you can set the temp in there. I think it defaults to 72F, or something like that.

The mash tun specific heat setting is a fractional number, not a temperature. It's got something to do with the way that the mash tun material absorbs and conducts heat, I think. Sorry, I'm not a physicist :)

I don't know the math behind it, but I think that it would virtually impossible to have the program work out the "average temp" between the grain and the mash tun, if they are indeed at different temperatures. Even though the tun is colder, it might not absorb as much heat as the grain as quickly. Does that make any sense? :)
 
Streb,
 The grain and mash tun temperature setting is a single setting (i.e. the temperature is assumed to be the same as you describe it).

 This can have some impact if there is a huge difference in temperature between the two.

 I will add "separating mash and grain temperature" to my to-do list as I too have experienced the joys of brewing in a very cold garage.

 In the meantime you can get an idea by trying both temperatures (your low and high) for the Grain/Tun Temperature input (its on the Mash Details button in the main recipe view).  For moderate conditions it does not change the infusion temperature dramatically, but if you look at the min and max boundaries you get a pretty good idea where the median might lie.  

Cheers!
Brad
 
Thanks for the quick reply!

Since I usually weigh and mill the grain the night before, I guess a simple solution for me would be to put the grain outside so that it will be the same temp as the MLT... :)

I'll play around with the Grain/Tun temperature, but equalizing the temps seems like the most straight forward way..

Cheers!

 
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