Author Topic: Mash In temp  (Read 9290 times)

Mindflux

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Mash In temp
« on: April 07, 2006, 12:43:12 PM »
I'm fiddling around with BeerSmith, since I have 21 days. I'm setting up a recipe I have formulated in Promash. I'm going through the steps in both programs to set in the Dough In(Mash in)/Mash out and Sparge.

Promash has been good to me in the past, but BeerSmith's strike temps are 7 degrees lower on the initial doug in and 4 degrees lower on the mash out.

I've got the thermal mass set the same, the grainbill is IDENTICAL.

What am I missing to account for this discrepancy?

Mindflux

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Re: Mash In temp
« Reply #1 on: April 07, 2006, 12:49:11 PM »
Also it seems no matter what, my "volume in kettle" is like 6.72 gallons.  Dispite the sparge volumes, grain bill or whatever. I have "Set boil volume based on equipment" set..

Is it just based on Batch Size +Evap rate x boil time + losses?

That comes out to about 6.5gal for me based on a 15% evap rate and .50 gal kettle loss and .25 Lauter tun loss.


Mindflux

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Re: Mash In temp
« Reply #2 on: April 07, 2006, 01:34:51 PM »
Image coming up

« Last Edit: April 07, 2006, 01:36:51 PM by Mindflux »

Offline BeerSmith

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Re: Mash In temp
« Reply #3 on: April 07, 2006, 02:32:40 PM »
Hi,
 You need to set up your equipment profile to match your individual equipment.  See the following:

  http://www.beersmith.com/equipment_setup.htm

 Note that the thermal mass is not the same as the mash tun specific heat - you may need to adjust this parameter to get the right mash in temperature.  Also you need the "Adjust temp for equipment" block checked in the mash section.

 If you have trouble tracking the water calculations try running them through the water needed tool first - it is layed out the same way as the water calculations in the main recipe but it is a bit easier to see what is going on using the tool.

Cheers!
Brad
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Mindflux

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Re: Mash In temp
« Reply #4 on: April 07, 2006, 03:24:25 PM »
I have my equipment set up, as well as "adjust temp for equipment" checked (FYI it changes the mash in temp by a degree or so). Not the 9 I'm currently missing.


I've got the mash tun material selected as Plastic (specific heat of .300) which in turn is the same as the thermal mass setting in Promash (.300).

any other ideas?
« Last Edit: April 07, 2006, 03:26:38 PM by Mindflux »

Mindflux

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Re: Mash In temp
« Reply #5 on: April 07, 2006, 03:30:07 PM »
« Last Edit: April 07, 2006, 03:30:26 PM by Mindflux »

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Re: Mash In temp
« Reply #6 on: April 07, 2006, 05:55:18 PM »
As I mentioned above the 0.3 factors are not equivalent.  BeerSmith uses the weight of the cooler, volume filled in the cooler and also the specific heat property of the cooler to calculate the infusion temperature using basic thermodynamics.  0.300 Calories per gram per degree C is the specific heat for a common type of plastic, but plastics vary tremendously.

If you have no point of reference 0.3 for specific heat is a good place to start, but some setups may require a higher number - perhaps 0.5 or higher to achieve the correct mash in temperature.  This should transfer well to new recipes once you set it.

Since you have a good track record already, you might want to bump the mash tun specific heat up in your equipment settings until you match your desired mash in temperature.

Doc
« Last Edit: April 07, 2006, 05:55:59 PM by admin »
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Mindflux

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Re: Mash In temp
« Reply #7 on: April 07, 2006, 05:58:45 PM »
Setting it at 1.00 gets me 178.1*...

.700 is a huge jump, is it not?

this also increases my mash out (to get to 168 ) at 211.9 (just 1/10th of a degree below boiling.)

Something is still off.  Promash calculates I'll need strike water at 206 to move my grain bed from 152 to 168.


« Last Edit: April 07, 2006, 06:02:49 PM by Mindflux »

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Re: Mash In temp
« Reply #8 on: April 07, 2006, 07:09:45 PM »
I noted that your mash tun is large (10 gal) while you are only making a 5 gal batch and filling a little over half the tun when you do your initial mash in.

Unlike other programs BeerSmith takes into account that you are not heating the whole mash tun.  In fact it calculates the mash volume needed and adjusts the temperature based on heating only part of the mash tun.  This might account for the differences you are seeing during the mash in.

In addition, I note that the 206 number that the other program is calculating is basically the number you would arrive at if you had no adjustement for equipment.  In fact, if you uncheck the equipment adjustment box in BeerSmith you get a temperature of 205.5.  I suspect that the other program might be using the equipment adjustments only for the initial mash in step and not subsequent steps - based solely on the numbers I'm seeing here.

BeerSmith uses your equipment settings, actual mash volume and grain and water temperature and volume to arrive at the numbers using basic thermodynamic equations.  Further it uses these for every step of the mash.

I think 1.0 is a little high for your specific heat - I suspect if you start around 0.5 as the specific heat you will hit very close to your desired strike temperature.  Also make sure you weigh your mash tun as the larger ones are generally pretty heavy.

You may be a little skeptical, but once you dial in your equipment settings the equations in BeerSmith are very accurate.

Brad

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Mindflux

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Re: Mash In temp
« Reply #9 on: April 08, 2006, 04:26:54 AM »
Alright.

Well I am a bit skeptical, afterall I've been using Promash for a year now and I almost always hit my target temperatures.

While Promash doesn't have a place for how heavy my mashtun is.. it does ask that you calculate it's thermal mass.. which ultimately makes for hitting your temps much more accurate.

I'll weigh out my tun today, it's a 48 quart igloo.. but I can't imagine it weighing a whole lot more than 9lbs.

Mindflux

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Re: Mash In temp
« Reply #10 on: April 08, 2006, 12:05:49 PM »
Alright.
Weighed the tun. came to 9.57 lbs.  That raised my mash in temp by 2 degrees.  However I'm still 7 or so short from promash's calculations.

Still mind boggling. As I said before promash has gotten me pretty spot on with my dough ins over the past year, so I have no reason to doubt the termperatures it gives me.