Mashing Temp Control with Mashtun

[prcdc]

We are running into issues getting proper temperature readings on our 300 gallon mashtun. We have two thermo ports on the tank and half the time none of them are ever close enough to even read properly. We have one at the top of the tank and one at the front in the middle (about 150 gallons maybe a bit less). We take samples with a scoop and of course when the mash gets to the middle of the tank when adding more grain and water it starts to read, but most of the time we are usually over our target temp and lose out on a lot of the conversion till we add colder water or more grain. Seems like a losing battle. I have tested both thermometers and they both work great. 

Mashtun is jacketed and heated with steam!

Any tips or tricks would be greatly appreciated.

[Skaalvenn]

How far does the probe go into the tank? I've got a still/mashtun and the probe is too short so the port gets full of grain resulting in unreliable readings.

 

I've got a batch fermenting in it right now. Digital handheld probes said 93 degrees while the tank thermometer said 80.

[Southernhighlander]

The thermometer probes were to short in some of our mash tuns to get good readings.  We have thermometers with longer probes now that solve that issue.  I am glad to sell you guys the thermometers.  If you are running my mash tuns I will send them out at no charge for the thermometers or shipping.  paul@distillery-equipment.com 417-778-6100

[kleclerc77]

Sometimes the probes get caked up and will therefore give you temps that are way off. Sometimes the seal isn't complete between the thermometer and the probe, leading to less egregious, yet still inaccurate readings. I've said fuck it and manually use a candy thermometer right into the mash that I know is very accurate. I'll be skeptical of any probe thermometer on a huge tank probably for the rest of my days.

[Silk City Distillers]

We had good luck getting a 36” rtd off eBay and using one of the top triclamp ports to get the business end down near the bottom of the tank.  It’s near the mixing agitator so we get what we think is a pretty representative measurement.

Ive seen plenty of them longer and shorter, so you should be able to find something.

[Southernhighlander]

I have them as long as you want, if anyone needs one.

[prcdc]

I will send a pick of the tank and you can tell me how long would make sense! I think my still pot needs the same deal. Thx

[starcat]

This matter is being overcomplicated and over thought. A properly installed thermowell with a properly installed probe and TEMP readout will work correctly. Its done in Commercial brewing all the time. There are also simple calcs for volumes of grain, and strike water at a given temperature that will result in you " hitting the target." Open, unprotected probes in a mash vessel are asking for trouble. If the mash is not properly stirred, its going to stratify. There would seem to be this tendency at large for a major lot of cut corner reinvention of the wheel on fronts that are already well tried, tested, and not that costly to do correctly.

[Southernhighlander]

prcdc,

Yes, please send me a pic and drawing if you have one.  We also have the thermowells for the temp probes if you need one.  We can do those in any length as well.  paul@distillery-equipment.com

 

Thanks.

[Skaalvenn]

15 hours ago, starcat said:

This matter is being overcomplicated and over thought. A properly installed thermowell with a properly installed probe and TEMP readout will work correctly. Its done in Commercial brewing all the time. There are also simple calcs for volumes of grain, and strike water at a given temperature that will result in you " hitting the target." Open, unprotected probes in a mash vessel are asking for trouble. If the mash is not properly stirred, its going to stratify. There would seem to be this tendency at large for a major lot of cut corner reinvention of the wheel on fronts that are already well tried, tested, and not that costly to do correctly.

I see a lot of tanks where the mixer is not designed properly. We have a center mount, vertical mixer, and the temperature of the water is Substantially different in the center of the tank than it is near the edges due to the water spinning, not mixing.  It gets a little better when the grain is added, but we have to occasionally reverse the agitator to actually mix the product...it's frustrating because a simple offset vertical mixer or a properly angled mixer would 100% alleviate the problem.

We take a temperature probe reading only after reversing our mixer (to cause a lot of agitation), and that number is substantially different enough from what the initial "spinning" readout is. We use a calculator and can usually hit our cook temp within a degree after grain-in, some enzymes are very sensitive to temperature/pH, so accurate mixing and readings are crucial to a distillery having either success or complete fauilure.

[Skaalvenn]

This is a video of what I'm currently working on, which shows the issue very well. I'm currently fermenting 700lbs of cupcakes (you heard that right). The yellow on the top is butter (which I'm curious how it's going to distill) but it clearly shows the lack of actual mixing despite rapid rotation...it's just stirring.

[richard1]

Have you considered, 1.  Modifying your agitator to come in at an offset and angled towards the centre bottom and 2.  Using a VSD to increase your speed.  Currently you are rotating at 24 RPM.

[starcat]

Skaalvenn, Fascinating, but the VID does not show on this end.

I am intrigued.

[Southernhighlander]

Skaalvan,

 

Most corn mash tuns have vertical agitators because of the very high viscosity of corn mash, large agitator paddles and very low rpms are typically used.   Generally whirlpooling does not cause a problem in this type of mash tun because of the low RPMs and high viscosity of grain in mashes. Angled agitators that must have smaller agitator paddles to fit in the same size vessel do not mix highly viscus corn mash very well because of the smaller paddles.  They do work well for less viscous mashes. High RPM agitators with small boat impellers really suck with most grain in mashes, but work incredibly well with very low viscosity mashes as long as they are not installed vertically.  

If you are running less viscous mashes and whirlpooling occurs there are 2 simple ways to solve the whirlpooling issue. 

Just flip your lower paddle and that should stop your issues.  If that does not give you the type of mixing that you want then email me and I will send you a baffle that will.  We are here to solve any equipment problems that anyone may have in this industry.

Out of the hundreds of corn mash tuns that we have out there we have only had 2 complaints concerning our mash tun agitators not mixing properly and we solved those issues immediately. 

 

We currently put baffles in all of our mash tuns except for our lauter tuns.   Our baffles make it impossible for whirlpooling to occur.

 

The best design changes that we have made over the many years that we have been designing distillery equipment were made because of customer feedback and from seeing the deficiencies in the equipment of others.  This forum has been a great place to see and learn from the equipment problems that people have.  If you have an equipment issue with our equipment or any distillery equipment just call or email us and we will solve your problems.  417-778-6100  paul@distillery-equipment.com

 

 

 

 

[Southernhighlander]

Another great option to promote good mixing is to cut several 1" holes in the agitator paddles.  The holes must be spaced properly.  We can make these agitator paddles for anyone that needs them. 

All of our new mash tuns also have cooling coils which help to create turbulence which promotes better mixing.

[Hudson bay distillers]

Paul can you explain the science behind these holes , 

[Southernhighlander]

Yes, like most mash paddles my father's and grandfather's mash paddles had holes in them and when we tested our agitator with the holes in the paddles with thick corn mash they mixed really well. They also work well for our customers that have them.

[Skaalvenn]

7 hours ago, Southernhighlander said:

Skaalvan,

Most corn mash tuns have vertical agitators because of the very high viscosity of corn mash, large agitator paddles and very low rpms are typically used.   Generally whirlpooling does not cause a problem in this type of mash tun because of the low RPMs and high viscosity of grain in mashes. Angled agitators that must have smaller agitator paddles to fit in the same size vessel do not mix highly viscus corn mash very well because of the smaller paddles.  They do work well for less viscous mashes. High RPM agitators with small boat impellers really suck with most grain in mashes, but work incredibly well with very low viscosity mashes as long as they are not installed vertically.  

If you are running less viscous mashes and whirlpooling occurs there are 2 simple ways to solve the whirlpooling issue. 

Just flip your lower paddle and that should stop your issues.  If that does not give you the type of mixing that you want then email me and I will send you a baffle that will.  We are here to solve any equipment problems that anyone may have in this industry.

Out of the hundreds of corn mash tuns that we have out there we have only had 2 complaints concerning our mash tun agitators not mixing properly and we solved those issues immediately.

We currently put baffles in all of our mash tuns except for our lauter tuns.   Our baffles make it impossible for whirlpooling to occur.

The best design changes that we have made over the many years that we have been designing distillery equipment were made because of customer feedback and from seeing the deficiencies in the equipment of others.  This forum has been a great place to see and learn from the equipment problems that people have.  If you have an equipment issue with our equipment or any distillery equipment just call or email us and we will solve your problems.  417-778-6100  paul@distillery-equipment.com

Thanks. I do not run corn. I do pretty thick wheat mashes, and it does turn over better as the thickness goes up, but it still doesn't mix properly (uneven temps).  You'll typically see vertical, center shaft mixers on very high viscosity liquids that have a centipoise equal to or exceeding toothpaste, as that type of mixer works well for those viscosity.  I was also told by you that baffles are not needed...

[Skaalvenn]

Here's the video of the cupcakes mixing, and all the butter.  You can see some of the chunks that wouldn't break up spinning aroud at the top, and they stay in the same orbit instead of being sucked down by the blades.

Man...that's a lot of butter.

 

 

 

 

[Southernhighlander]

Baffles are not typically needed in these tuns

1 hour ago, Skaalvenn said:

Thanks. I do not run corn. I do pretty thick wheat mashes, and it does turn over better as the thickness goes up, 

These mash tuns are specifically built for corn and other grain in mashes. My customers do not generally have any mixing issues with them.  In fact we have several customers that have used our mash tuns for years and then purchased larger ones from us.  One customer purchased 3, the last one being 2,500 gallon total capacity.   His distilling capacity is over 7,000 gallons of mash per day using my stills.  All of that mash is done in my mash tuns   He is on the forum though I have never seen him post.  He has been running my mash tuns for almost 8 years with no mixing issues. 

You are doing something very different.     You will always have temperature differences in different areas of the tun  from the bottom to the top and from the center to the outside because the turn over is never instant and other factors. and you will probably allways get chunks of cupcakes because they come in chunks.  However that doesn't matter because I am here to help you resolve any issues that you may have.  Does your tun have the cooling coil?

  I do apologize if you received a short thermometer by mistake.   We are glad to send you a thermometer with a long probe with a thermowell at no charge for shipping or the parts.  As far as the mixing issues with your cupcake mash I am glad to help you solve that issue at no charge.  Flipping your lower agitator paddle should be all that you need to do however if that does not work for you I am glad to send you  paddles that will give you better mixing, or a baffle.  Anyone of these changes will prevent whirlpooling and they won't cost you anything.

We have always taken care of any issues that our customers have let us know about and we will always do so.   The baffles in our current tuns are removable and there is no possibility of whirlpooling no matter what you are mashing.   The baffles are not really needed for grain in mashes like corn and rye however they will improve the mixing of thinner mashes or mashes that start out with chunks like cup cakes.

[Southernhighlander]

Aside from grain in mashes these tuns are great for rice as well as patato and we have several customers who have been using them for that for years.  We have one customer who mashes black eyed peas in one.  He has been doing that for over 7 years and as far as I know that tun is still going strong.  It is 600 gallon with an 8hp agitator that spins at around 16 RPM.  

[Silk City Distillers]

Skal can I call you regarding cupcakes?  No, seriously.

[Skaalvenn]

1 hour ago, Southernhighlander said:

Baffles are not typically needed in these tuns

These mash tuns are specifically built for corn and other grain in mashes. My customers do not generally have any mixing issues with them.  In fact we have several customers that have used our mash tuns for years and then purchased larger ones from us.  One customer purchased 3, the last one being 2,500 gallon total capacity.   His distilling capacity is over 7,000 gallons of mash per day using my stills.  All of that mash is done in my mash tuns   He is on the forum though I have never seen him post.  He has been running my mash tuns for almost 8 years with no mixing issues. 

You are doing something very different.     You will always have temperature differences in different areas of the tun  from the bottom to the top and from the center to the outside because the turn over is never instant and other factors. and you will probably allways get chunks of cupcakes because they come in chunks.  However that doesn't matter because I am here to help you resolve any issues that you may have.  Does your tun have the cooling coil?

  I do apologize if you received a short thermometer by mistake.   We are glad to send you a thermometer with a long probe with a thermowell at no charge for shipping or the parts.  As far as the mixing issues with your cupcake mash I am glad to help you solve that issue at no charge.  Flipping your lower agitator paddle should be all that you need to do however if that does not work for you I am glad to send you  paddles that will give you better mixing, or a baffle.  Anyone of these changes will prevent whirlpooling and they won't cost you anything.

We have always taken care of any issues that our customers have let us know about and we will always do so.   The baffles in our current tuns are removable and there is no possibility of whirlpooling no matter what you are mashing.   The baffles are not really needed for grain in mashes like corn and rye however they will improve the mixing of thinner mashes or mashes that start out with chunks like cup cakes.

 

Thanks.  This cupcake thing is probably a one time deal...unless it turns out amazing. The color contrast with the butter on top just does a very good job of highlighting what is happening with the motion of the fluid. I'll send you a PM.

Silk, feel free to give me a call. Google Skaalvenn and it will give you the number.  I've never made cupcake spirits before, but I can say it is by far the best smelling thing I have ever done in the distillery and I'll be sad when that aroma is no longer here.

[kleclerc77]

On 10/3/2019 at 9:39 AM, Southernhighlander said:

High RPM agitators with small boat impellers really suck with most grain in mashes, but work incredibly well with very low viscosity mashes as long as they are not installed vertically.  

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I have to say, our angled high rpm agitator with boat style props works incredibly well with our viscous grain in mashes. An easy mistake to make is having the props either mounted upside down, or have them rotating the wrong direction. Either way it will look like they're working when they're not running the right direction, therefor not achieving what they are really capable of. 

[Southernhighlander]

46 minutes ago, kleclerc77 said:

I have to say, our angled high rpm agitator with boat style props works incredibly well with our viscous grain in mashes. An easy mistake to make is having the props either mounted upside down, or have them rotating the wrong direction. Either way it will look like they're working when they're not running the right direction, therefor not achieving what they are really capable of. 

 

Below is a picture of a vendome mash tun.  They have been building mash tuns for over 100 years.  My design is the same as theirs which is basically the same as 80% to 90% of the grain in mash tuns out there. You see this same tun design at Jack Daniels and Jim Beam and every other large distillery that I have toured.   I have never seen a grain in mash tun with an angled shaft with little boat impellers.  What brand is your grain in mash tun?

  Every mash tun that I have ever seen had a vertical shaft and large impellers or if for Barley a large low RPM vertical shaft with rakes and chains or chisels.  We have built large numbers of both types and we sell the shit out of them.  In fact I sold a 600 gallon one yesterday.

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