• Welcome to the new forum! We upgraded our forum software with a host of new boards, capabilities and features. It is also more secure.
    Jump in and join the conversation! You can learn more about the upgrade and new features here.

Mash Tun Info.

mbg

Master Brewer
Joined
Oct 22, 2004
Messages
65
Reaction score
0
I retired my old mash tun for a new 70Qt. Cloeman Xtreme. Thought I'd be scientific and calcluate the heat capacity by adding hot water to the tun. I'm a little unassured of the results:

tun at start 73
4 gal. hot water 162.5

155.8 @ 5min.
153.8 @ 10 min.
152.2 @ 15min.
150.5 @ 25 min.
149.5 @ 30 min.

if I use this link to calculate equivalent water vol.:

http://www.haandbryg.dk/mashcalc.html#rest


I get about 3 quarts or 6.26# of water. This inputed into BS causes my water temps to go up quite a bit compared to using tun weight and spec heat.

I've made three batches with this tun and had problems hitting temp but I don't see the type of loss over time that this test showed.

Does this sound right? Only thing I noticed is the lid on this cooler is easy to open - maybe loosing heat at the lid?

Thanks,

Mike

 
While I was grilling I had a chance to run a second test. What I noticed was to run this test right you should not open the lid to take temps - you loose too much heat this way. Also, the tun does not really seem to stabilize.

What I did was use the 10min. reading and it seemed to match well with someone with the cooler came up with by varying tun weight.


Mike
 
I use a cooler. It doesn't lose that much heat when there is grain in it.

I sometimes miss temps by a  degree either way. Though my water measurements have never been %100 accurate.



You should be able to dial in the specific heat to get pretty close.
 
You can find the exact specific heat of your mashtun with the Mash Adjust tool and a floating thermometer.

Accurately weigh your mashtun.
Accurately measure out 3 gallons of water.
Heat the water to 170 (actually, any temperature will do, but this is closer to brewing).

In the tool:
Starting Water volume: 0
Weight of grain: 0.0001
Starting mash temperature: ambient temperature of the room
Weight of mashtun: as weighed
Mashtun Specific Heat: 0
Water Addition Temp: 170 or the exact temperature you use.
The mash water ratio will read something crazy. Ignore that.

Quickly add the heated water and floating thermometer to the mashtun. Cover and wait 10 minutes.
Read the water temperature.
Input the water temperature as "Target Mash Temperature" in the tool.

Now, simply change the Mashtun Specific heat until the "Water Volume to Add" matches 3 gallons.
That's your mashtun's specific heat!
 
mbg-bs said:
Does this sound right? Only thing I noticed is the lid on this cooler is easy to open - maybe loosing heat at the lid?

You could be losing heat around the seal of the lid. I saw someone mention opening the lid - how are you taking the measurements. When I used a cooler, I drilled a hole in the lid and put a long stem thermometer through it so I could keep the lid closed.

When I did my initial measurements for cooling losses, I used water, but when I actually mashed, I found that the mash held temps better than plain water, and I wonder if the more dense mash bed retains heat better than plain water.
 
BlackIslandBrewer said:
When I did my initial measurements for cooling losses, I used water, but when I actually mashed, I found that the mash held temps better than plain water, and I wonder if the more dense mash bed retains heat better than plain water.

This would seem to make sense.  Pure water also has more open surface to allow cooling that your mash and the grain retains a LOT of heat.  A bowl of pasta holds heat a LOT better than a bowl of water and that is just processed grain. 

If it were me, I'd make a batch in it and pick a middle of the road temp.  You can always add some boiling water to bring your temps up if you need to raise your temp, or cooler to bring them down.  There simply is not better test IMO that real life, real situation use.
 
Mtnmangh said:
If it were me, I'd make a batch in it and pick a middle of the road temp.  You can always add some boiling water to bring your temps up if you need to raise your temp, or cooler to bring them down.  There simply is not better test IMO that real life, real situation use.
What I actually did was to preheat my mashtun and let BS sort out the thermodynamics. On my first dough-in, I hit my temps exactly, but I was ready with cold water if needed, and can direct fire to bring up the temps when necessary.
 
Guys, I am a new all grain brewer. I am using a 38Litre Colman cooler for a mash tun. I was concerned about the food grade/non food grade plastics used by Colman. I got a very nice letter back as follows: Thank you for contacting Coleman. I would be more than happy to assist you today.
Putting a hot liquid in a Coleman® Cooler can cause the air bubbles in the insulation to swell which will warp the inner liner and can cause the outer casing to split. Please note, our coolers are intended for recreation purposes and are not specifically designed for commercial applications like a restaurant. Our cooler material is:Outer shell is HDPE. (High Density Polyethylene) The liner, lid, and spout are polypropylene.
Fine and dandy! it is food grade. That is all I was concerned about. Next, I conducted a heat loss test, filling mine with 75°C/157°F water. I closed the lid and at the one hour point, it had lost 5°C. Not satisfactory for steeping grains. I had checked the temp in the top of the cooler and found it to be 55°C indicating considerable heat loss through the lid. Makes sense considering that they are only made for cooling purposes.
I then drilled a series of holes in the top of the lid and filled it with a large can of foam insulation material. Bingo no more heat loss through the lid. The top was a cool as the sides in the first mash out.
Comment was made here about density of grain holding heat. That is a true statement. The first use of my cooler as a mash tun showed no heat loss over a period of 1 hour.  I am thrilled with it!
I am now working on adding a pump and copper tubing dispersing sprayer, to lay on top, to recirculate the wort over the one hour of steeping. I will then drain off the wort into a separate container followed by the sparging process, using the same system. Can't wait to get that going!

 
Cobrarog said:
I then drilled a series of holes in the top of the lid and filled it with a large can of foam insulation material. Bingo no more heat loss through the lid. The top was a cool as the sides in the first mash out.
Comment was made here about density of grain holding heat. That is a true statement. The first use of my cooler as a mash tun showed no heat loss over a period of 1 hour.  I am thrilled with it!
I am now working on adding a pump and copper tubing dispersing sprayer, to lay on top, to recirculate the wort over the one hour of steeping. I will then drain off the wort into a separate container followed by the sparging process, using the same system. Can't wait to get that going!

Can you post pictures of the filled holes and what foam did you use (low expansion)?

Thanks,

Mike
 
BeerSmith has me mashing in WAY too hot, no matter how I set the specific heat of my tun.  I think I'm just gonna have to uncheck the box that tells it to adjust the mash to my equipment.  My last mash I had to add 16oz of ice cold water to get my mash back in the neighborhood I was looking for.  I was aiming at 152.  I had me adding 4 gallons of 167 degree water.  My mash was then at almost 157.  I also preheat my tun with boiling water (ala Palmer) and that may make a big difference.  I only lost one degree in an hour.  I use a converted 10 gallon round coleman water cooler.  Thing holds heat like crazy!  I love the software, but I still need some tweaking.
 
If you are pre-heating the MLT with hot water, then you don't need it checked.  The check-box is meant to make you aim higher when NOT pre-heating. 

So that's 2F of it.  Subtracting that 2F and it's still 15F higher that your target.  My set-up is usually 11F higher than target. 

That's a 5-gallon batch of 1.055 and 11 pounds grain here.    What are you doing there?    Post your Equipment Profile if you want.  Something does seem to be off.
 
About 12.75 lbs of grain.  I have always mashed in with a little higher malt/grist ratio, but I decided to go with the software (first batch I've made with it)  Everything went well, except for my volume.  I ended up with 6+ gallons of 1.052, which when I do the math has me hitting my numbers on the nose (5.5 gal of 1.057).  I have in recent years done 5.5 to end up with 5 gallons actually going into the bottles after trub loss.  This was also my fist batch sparge (I've always fly sparged).  Anyway, back to the issue at hand...my equipment profile...

Equipment Profile: Greg
Batch Size: 5.50 gal

Mash Tun Volume: 10.00 gal
Mash Tun Weight: 7 lbs
Mash Tun Specific Heat: 0.10 (I lowered this to try and get my numbers closer)
Lauter Tun Deadspace: 0.00 gal

Boil Size: 6.50 gal
Boil Time: 60 min
Evaporation Rate: 15.4 %
Calculate Boil Size: FALSE
Kettle Top Up Water: 0.00 gal
Hop Utilization Adjustment: 100.00 %

Trub/Chiller Loss: 0.25 gal
Cooling Loss: 4.00
Top Up Water into Fermenter: 0.00 gal

(Perhaps I should just try not preheating the tun and see what happens)
 
Something seems off in here, based on your comments.  If you started with 6.5 and really burned off 15.4%, that would've hit 5.5, and then deduct the .25 lost and the 4% cooling and you'd actually be under your goal of 5.5 

Re-check the box that makes BS2 calculate your boil volume and see what that says. 

Mtnmangh said:
Batch Size: 5.50 gal

Boil Size: 6.50 gal
Boil Time: 60 min
Evaporation Rate: 15.4 %
Calculate Boil Size: FALSE

Trub/Chiller Loss: 0.25 gal
Cooling Loss: 4.00
 
When I rechecked the box, it came out to 6.98 into the boil.  This sounds about right as that's what I got.  Even after the boil off (which i have figured out the old fashioned way and have had my kettle a while - 1 Gallon) I was still at 6+ gallons (I have no marks above 5 gallon in my fermenting tank).  This would make sense.  The question is why....BS2 still shows me at 5 gallons into the bottles due to 1/2 gallon loss in primary/secondary.

BTW..if I uncheck the "adjust mash for my equipment" box, I come out to almost exactly what you have (about 11 degrees over target).  From my experience this seems about right.  I was using an online resource for years but didn't really know about body and mash temps until relatively recently.  I'm trying to be more accurate about everything now.  I could just leave the box unchecked, but that still doesn't help me with the volume issue. 

Another thing that seemed odd to me is that you cannot adjust the water/grist ratio to make your mash stiffer/looser (at least that I can find).
 
You can adjust the grist ratio on the mash in step.
Screen-Shot-2013-11-20-at-7.31.57-PM.png
 
You can find the exact specific heat of your mashtun with the Mash Adjust tool and a floating thermometer.

Accurately weigh your mashtun.
Accurately measure out 3 gallons of water.
Heat the water to 170 (actually, any temperature will do, but this is closer to brewing).

In the tool:
Starting Water volume: 0
Weight of grain: 0.0001
Starting mash temperature: ambient temperature of the room
Weight of mashtun: as weighed
Mashtun Specific Heat: 0
Water Addition Temp: 170 or the exact temperature you use.
The mash water ratio will read something crazy. Ignore that.

Quickly add the heated water and floating thermometer to the mashtun. Cover and wait 10 minutes.
Read the water temperature.
Input the water temperature as "Target Mash Temperature" in the tool.

Now, simply change the Mashtun Specific heat until the "Water Volume to Add" matches 3 gallons.
That's your mashtun's specific heat!

I'm resurrecting this old thread to see if anyone has done this to find your mash tuns specific heat? It looks straightforward so before I give it a try was wondering how close it gets you!
 
Well, I guess no one has done this, so I gave it a shot. My mashtun is a keggle w/ 2" foam glued to it. After the experiment my mash tun's specific heat came out to .39. I guess we'll see how this goes on my next batch.
 
BeerSmith has me mashing in WAY too hot, no matter how I set the specific heat of my tun. I think I'm just gonna have to uncheck the box that tells it to adjust the mash to my equipment. My last mash I had to add 16oz of ice cold water to get my mash back in the neighborhood I was looking for. I was aiming at 152. I had me adding 4 gallons of 167 degree water. My mash was then at almost 157. I also preheat my tun with boiling water (ala Palmer) and that may make a big difference. I only lost one degree in an hour. I use a converted 10 gallon round coleman water cooler. Thing holds heat like crazy! I love the software, but I still need some tweaking.
That's fantastic! Tweaking software settings can be a part of the learning curve, and it's great that you're actively working to refine your system.
 
Well, I guess no one has done this, so I gave it a shot. https://www.viberate.com/music-analytics/ My mashtun is a keggle w/ 2" foam glued to it. After the experiment my mash tun's specific heat came out to .39. I guess we'll see how this goes on my next batch.
It's always interesting to see how specific characteristics of your equipment can impact the brewing process. A keggle with 2" foam sounds like a solid setup.
 
Back
Top