Infusion Algorithm

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Hopeye

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Hi,

Would anyone know the algorithm for calculating the infusion temperature in a multiple rest mash. I have the Strike Water infusion temp calc, but, that doesn't work for steps 2 or 3. I also have the calc to determine the amount of infusion water to add given the infusion temperature of the water.

What I need is to calc the infusion temp given the Target Temperature required, the Current Temperature of the mash and the amount of water that will be added.

Does that make any sense ??

:blink:

Cheers,
David
 
David,

That's why I gave up on 'em and stick with a single-infusion (not necessarily the right thing to do though).

Unless you've got some form of direct heat it's always a bit of a crap-shoot. I generally wound up with too much liquid volume and not enough of a temp hike or overshooting and having to add cold water. I'd follow calculations and still wind up in trouble.

Think the thermal mass of the vessel plays some sort of part in the whole scope of things but it's got me beaten.

Always had to resort to pulling part of the mash for a decoction and winding up with a very protracted brewing day, which is long enough even when doing a single temp rest.

Warren -
 
Hopeye,

Download a demo version of Beersmith and it will do all of the calculations for you, including the thermal mass of your mash vessel. If you like the program you can then buy it on line.

Andrew
 
Hi Hopeye

I presume you're doing the calculations in something like Excel. This should get you pretty close.

the input fields would be:
Weight of grain (WoG)
Initial Ltr:Kg mash ratio (IMR)
Desired mash temp (DMT)
Current mash temp (CMT)
Temp of water addition (100c)

You then calculate for the litres needed, which is:
(WoG*(0.4+IMR))*((DMT-CMT)/(100-DMT))

I checked the results based upon 5kg mashed at a ratio of 2.5:1, with an initial rest of 44 and a desired next step of 65. This calculation says to add 8.7ltrs and Promash says to add 8.8ltrs, so it's pretty close.

Cheers
MAH
 
You can use software, Beersmith, Strangebrew, Promash, etc. or you can just add boiling water, stir, check temp, add more boiling water and so on.

Once you have done a few step mashes using this method, you will get to know approximately how much boiling water is required to go from step to step.

The trick is to keep the water at a rapid boil and use a jug (or saucepan) to pour it into the mash tun, which should be as close as possible to the water. This way you minimise the heat loss during the transfer and use as little water as possible to raise the temperature.

Beware of scalding when removing the boiling water. Wear a glove or use a saucepan - they have longer handles than jugs.

Steve
 
Hi MAH,

I've already got the algorithm to calculate how much water to add, what I'm looking for is a algorithm that will tell me how hot 20 litres of water needs to be to raise the mash (currently at a ratio of 1.5:1 (30 litres:20kg)) from 60 to 65 degrees celsius. I'm adding onto my own software that I've already built for K&K (which contains all my history of brewing) because I'm gearing up to go AG, so I'd like to try and find the algorithm (instead of plugging the values into some other package).......
 
Hopeye

Well the formula will stay the same, you just need to change what you're solving for, so instead plug in the volume and solve for temperature.

Cheers
MAH
 
Hopeye said:
I've already got the algorithm to calculate how much water to add, what I'm looking for is a algorithm that will tell me how hot 20 litres of water needs to be to raise the mash (currently at a ratio of 1.5:1 (30 litres:20kg)) from 60 to 65 degrees celsius. I'm adding onto my own software that I've already built for K&K (which contains all my history of brewing) because I'm gearing up to go AG, so I'd like to try and find the algorithm (instead of plugging the values into some other package).......
[post="48241"][/post]​

If I understand you right, Brewsta will do that for you.

Having said that, I find subsequent steps tend to under shoot because the ideal thermodynamic model doesn't quite fit the real world. For example, I measure the temp of the water in the HLT, what comes out the other end of the pump is a little lower. The starting temperature of the grain bed varies depending on where you measure it etc.

Don't let me put you off trying, and by all means, suggest some tweaks to the model so that Brewsta allows you to nail it every time. I find I am nailing the first infusion step right on the head.
 
Yeah Sosman,

As I'm adding onto my current software (Visual Basic) (VB - yeah I know it sounds like shite beer), I'd like to get the algorithm so I can code it directly into my system, as opposed to plugging the values into some other system to get the results that I would then plug into my system. It's just easier if my system calcs it itself.........

Though, I didn't try installing Brewsta myself, but, I kinda gather it would calc the volume given an infusion temp as opposed to calc'ing the temp given a set volume.......

Cheers & Beers
 
Hopeye said:
Though, I didn't try installing Brewsta myself, but, I kinda gather it would calc the volume given an infusion temp as opposed to calc'ing the temp given a set volume.......
[post="48336"][/post]​
Don't say I didn't tell you.
 
Here is the calculation that I teach with explaination below:

Wa = ((Tf-Ti)(.2G+Wm))/ (Tw-Tf)

Wa = qts boiling water needed
Tf = rest temperature you want to reach (Final Temp)
Ti = temp you are at right now (Initial temp)
G = pounds of grain
Wm = qts water in mash (you know from how much strike water you added)
Tw = infusion water temp (I always use 212 boiling)

Very simple and straight forward. I also have them for strike temp, hop additions for both weight and IBU's, gravity contributions, etc.
 
And if anyone is interested in some python source code, you can download the Brewsta source.

The relevant routines are in mash.py.

cheers
 
BJCP Education Director said:
Here is the calculation that I teach with explaination below:

Wa = ((Tf-Ti)(.2G+Wm))/ (Tw-Tf)

Wa = qts boiling water needed
Tf = rest temperature you want to reach (Final Temp)
Ti = temp you are at right now (Initial temp)
G = pounds of grain
Wm = qts water in mash (you know from how much strike water you added)
Tw = infusion water temp (I always use 212 boiling)

Very simple and straight forward. I also have them for strike temp, hop additions for both weight and IBU's, gravity contributions, etc.
[post="52007"][/post]​
And that is great when you measure stuff in US units. We've been using SI units here now for a few decades.
 
sosman, you should know better than to mention the metric system to an American!
They think it's a French plot to make them guzzle "gas" by the litre. <_<

that 212oF always looks stupid to me. Thanks Professor Fahrenheit! :p
 
Backlane Brewery said:
They think it's a French plot to make them guzzle "gas" by the litre. <_<

[post="52028"][/post]​

LOL! :lol: Just a minor correction Backlane, shouldn't that be "liter" :p

Warren -
 
Sosman, I have installed Mac OS 10, will upgrade that to 10.2, then re-download Brewsta and give it a whirl, then post some notes back here if you like on Brewsta from a Mac perpective

Jovial Monk
 
While adding hot water bit by bit will essentially do the job, it helps with planning if you can see approx. how much water you're going to need, so you can adjust your mash stiffness and don't end up having to get that extra litre of boiling water in in a hurry.
A simple Excel spreadsheet, it would take 15 seconds to enter the data in, get your final number and round up a litre or so as a safeguard... of course this is being unnecessarily critical...
 
Jovial_Monk said:
Sosman, I have installed Mac OS 10, will upgrade that to 10.2, then re-download Brewsta and give it a whirl, then post some notes back here if you like on Brewsta from a Mac perpective
[post="52411"][/post]​
I appreciate almost any kind of feedback. You might want to PM me or use the Brewsta forums on http://sourceforge.net/projects/brewsta/.
 
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