Avoid Temp Swings in MES (By Bear)

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Temp control must be the #1 critical factor for a successful smoke.  It makes sense that Masterbuilt should perfect this.  Taking ~2 hours to reach stable temps seems ridiculous.  Still love my MES BT.  Just staying.......
 
It looks like your button sensor has creosote.  You may need to clean it.

Yes, that is from one smoke. I can never seem to find the fine to clean the smoker after a smoke, so. I do it the night before the next smoke after I've prepped the meat.

That won't work too good----I believe that button in your picture is the safety heat sensor.

The one that looks like a toggle switch is the one that is used for the heat regulation.

Bear
So where is this toggle switch sensor? I don't see anything else in the smoker that could be a sensor. I have the new gen 2.5 Bluetooth model from Sam's.
 
So. Here are the results of my testing. Of course this could all moot of Bear is right and I'm testing the wrong sensor, but I don't think I am.

If you look closely at this picture...
You will see the 2 meat probes dangling in front of the button sensor, about a half inch in front of it. But since I couldn't find the clippy things that holds the Maveric's smoker sensor in place, I had to wedge it between the grill and the back wall of the sensor. This turned out to be a good thing.

When I started the unit and set the temp at 225, the two meat probes rose very quickly, compared to the MES and Maveric smoker temp displays. In fact, the two meat probes reached 300 degrees before the heater shut off when the MES display reached 225. The two meat probes read very close to each other as did the two smoker temp readings.

I was only able to watch this through a couple of cycles, but the differences between the two smoker temp read outs and the two food temp read outs started at about 80 degrees and settled at about 60 degrees by 1 hour.

I then opened the door and removed all there probes from the bottom grill. I bound them together and set them on the center of the second rack. By the time I got this done, the smoker had cooled off considerably, according to the 3probes, but not so much according to the MES sensor. Once I closed the door, it recovered quickly. I was impressed that the three probes all read within three degrees of each other. I was also impressed that the temp swings were all about the same and from about 215-230. This would be after about 1.5 hours of operation.

So here is my theory.... If you look back at the picture, you will see that the sensor button is attacked to the back wall, which acts like a heat sink. By wedging the Maveric smoker probe between the grill and back wall, that also acted as a heat sink, hence those two reading similarly. With the water pan in place the heat from the element is diverted to the four sides of the box as it rises up where it hits the top them curls down the center. That upward draft on the back edge is why the meat prob temps read so high. It also explains why if you leave the MES meat probe in its holder why it reads so high.

My next step will be to place the three probes on the center of the three top racks and replete the test.
 
Bearcarver, I want to thank you for taking so much time to explain the temperature swings and how to help control them.      I have a 40 inch stainless steel Masterbuilt that I bought from Sams club probably 6 years ago.     Just yesterday, I took it out of the box and followed the seasoning procedure in the instructions.   I also ran the anmps smoker while seasoning and it worked great.     I used the Mavrick ready Check temp guage with two probes to watch the temperatures during seasoning.     The Mavrick probes showed about a 15 degree higher temperature than the readout on the smoker.     I wasn't concerned about this.  This morning, I put a 9 pound pork butt on the Masterbuilt about 9 am and have observed the temperature swings you detailed.    I set the temperature at 240 degrees and started smoking.  The pork butt was on sale for 99 cents a pound so I thought it would make a good first attempt on the smoker.     One thing I have always heard about was the stall, since I this is the first time I have used a temperature prove, I really didn't know what to expect.     Well, the pork put steadily, but slowely climbed in temperature until it hit 163 degrees and then it dropped to 161 degrees and stayed there for about 2.5 hours.    It finally started slowly climbing again and finally the pork butt is at 203 degrees.     I am going to take it out and wrap it in foil and go to bed.    This has been a long day.

Thanks Again Sir for you expertise!
 
Yes, that is from one smoke. I can never seem to find the fine to clean the smoker after a smoke, so. I do it the night before the next smoke after I've prepped the meat.
So where is this toggle switch sensor? I don't see anything else in the smoker that could be a sensor. I have the new gen 2.5 Bluetooth model from Sam's.
I clean the glass in mine before each smoke too, instead of after.

The thing you're putting your probe next to is the heat safety sensor in mine, and it looks just like yours (behind the left hanging probe).

The toggle switch looking sensor that measures the heat for the controls on mine is in the clean spot just below the probe on the right in this picture.

http://s836.photobucket.com/user/Bearcarver_2009/media/DSCN1562.jpg.html


 
 
 
Temp control must be the #1 critical factor for a successful smoke.  It makes sense that Masterbuilt should perfect this.  Taking ~2 hours to reach stable temps seems ridiculous.  Still love my MES BT.  Just staying.......
I'm not a watt burner, so I don't have any experience with MES,  But I think what Bear is trying to do is let people know who have these units is how they can maintain their temp and get that perfect smoke. Seems pretty self explanatory.

You should start your own thread and contact Masterbuilt and explain to them on how to improve their product., Never  Know till you try.   ..............  Just Sayin !!!

Gary 
 
So. Here are the results of my testing. Of course this could all moot of Bear is right and I'm testing the wrong sensor, but I don't think I am.

If you look closely at this picture...

You will see the 2 meat probes dangling in front of the button sensor, about a half inch in front of it. But since I couldn't find the clippy things that holds the Maveric's smoker sensor in place, I had to wedge it between the grill and the back wall of the sensor. This turned out to be a good thing.

When I started the unit and set the temp at 225, the two meat probes rose very quickly, compared to the MES and Maveric smoker temp displays. In fact, the two meat probes reached 300 degrees before the heater shut off when the MES display reached 225. The two meat probes read very close to each other as did the two smoker temp readings.

I was only able to watch this through a couple of cycles, but the differences between the two smoker temp read outs and the two food temp read outs started at about 80 degrees and settled at about 60 degrees by 1 hour.

I then opened the door and removed all there probes from the bottom grill. I bound them together and set them on the center of the second rack. By the time I got this done, the smoker had cooled off considerably, according to the 3probes, but not so much according to the MES sensor. Once I closed the door, it recovered quickly. I was impressed that the three probes all read within three degrees of each other. I was also impressed that the temp swings were all about the same and from about 215-230. This would be after about 1.5 hours of operation.

So here is my theory.... If you look back at the picture, you will see that the sensor button is attacked to the back wall, which acts like a heat sink. By wedging the Maveric smoker probe between the grill and back wall, that also acted as a heat sink, hence those two reading similarly. With the water pan in place the heat from the element is diverted to the four sides of the box as it rises up where it hits the top them curls down the center. That upward draft on the back edge is why the meat prob temps read so high. It also explains why if you leave the MES meat probe in its holder why it reads so high.

My next step will be to place the three probes on the center of the three top racks and replete the test.
Exactly. I thought that was a given, which is why we don't even consider what the meat probe says when it's in its holder, and why we never let any measuring part of a probe lay against any metal in our smokers, and expect any accuracy in measuring the air temp.

Some people support their probes with a potato, some use a block of wood to keep their probes away from metal, and I hang mine through a rack with electrical tape on the top to secure the probes from moving from where I put them.

You can see that in my picture above, where I have a probe on each side to balance out the heat from left to right with the use of my heat deflector below.

Bear
 
 
Bearcarver, I want to thank you for taking so much time to explain the temperature swings and how to help control them.      I have a 40 inch stainless steel Masterbuilt that I bought from Sams club probably 6 years ago.     Just yesterday, I took it out of the box and followed the seasoning procedure in the instructions.   I also ran the anmps smoker while seasoning and it worked great.     I used the Mavrick ready Check temp guage with two probes to watch the temperatures during seasoning.     The Mavrick probes showed about a 15 degree higher temperature than the readout on the smoker.     I wasn't concerned about this.  This morning, I put a 9 pound pork butt on the Masterbuilt about 9 am and have observed the temperature swings you detailed.    I set the temperature at 240 degrees and started smoking.  The pork butt was on sale for 99 cents a pound so I thought it would make a good first attempt on the smoker.     One thing I have always heard about was the stall, since I this is the first time I have used a temperature prove, I really didn't know what to expect.     Well, the pork put steadily, but slowely climbed in temperature until it hit 163 degrees and then it dropped to 161 degrees and stayed there for about 2.5 hours.    It finally started slowly climbing again and finally the pork butt is at 203 degrees.     I am going to take it out and wrap it in foil and go to bed.    This has been a long day.

Thanks Again Sir for you expertise!
I Thank You Sir !!

You did exactly the right thing!!

And 99 cents for Pork Butt----I haven't seen that around here in over 5 years!!

Thanks again for your comment.

Bear
 
I clean the glass in mine before each smoke too, instead of after.

The thing you're putting your probe next to is the heat safety sensor in mine, and it looks just like yours (behind the left hanging probe).
The toggle switch looking sensor that measures the heat for the controls on mine is in the clean spot just below the probe on the right in this picture.
 

I only have the one sensor, the one on the right side where your toggle sensor is, only higher, just below grate 3. There is nothing on the left side. They must have combined them on gen 2.5???
 
Exactly. I thought that was a given, which is why we don't even consider what the meat probe says when it's in its holder, and why we never let any measuring part of a probe lay against any metal in our smokers, and expect any accuracy in measuring the air temp.

Sorry, I must have misunderstood mumel's earlier post. I thought he was concerned about the differences in temp between the built on sensor and the Maveric probe placed right next to it. But, I enjoyed doing my experiments and will certainly do more.
 
The bottom line is that after 1.5 hours, the Mav probe and the MES built in temp probe are very similar.  But in the first 30 minutes, the temps are WAY off, differing as much as 75F.  Thats why the MES continues to heat in the beginning even though the desired temp has been hit. 

Workarounds include baby'ing the temps in the beginning as per Bear's instructions, or preheating it for at least 45min.    For a 14 hour smoke, its not a big deal, but for shorter smokes like salmon, BCBs, chicken etc, this is a huge deal, and something Masterbuilt needs to fix with their next gen smoker.
 
Does anyone have an iGrill2?  I would be curios to see what the chart looks like if you turn your smoker on and set it to 225F, and how long it actually takes to reach that temp consistently.
 
I only have the one sensor, the one on the right side where your toggle sensor is, only higher, just below grate 3. There is nothing on the left side. They must have combined them on gen 2.5???
Hmmmm, That could be what they did---Funny you're the first to mention that----Good to know!!

I used to wonder why they weren't together before, so I figured that couldn't be done for some reason.

Thank You Very Much Steve!!

Bear
 
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  Avoid temp swings in MES by purchasing a WSM...... problem solved with benefits!

It's been awhile since I've used my 40" MES to hot smoke. Almost every smoke was a little different do to the many variables both ambient and internal. From what I remember..... I use to preheat my MES to a higher temp than where I wanted to smoke at, mainly to give me enough time to load the meats without a huge temp drop before I closed the door. Then as things went along, I had to adjust temp set point up or down throughout the smoke. As the temp difference got tighter between chamber and meats the less adjustment was needed and it eventually got to a point where she was pretty steady the rest of the way. One has to learn his or her smoker and take variables into consideration, by no means is it "set it and forget it". At the time I had lots of fun learning how to smoke meats with my 40" MES.

Good luck and enjoy!
 
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Wow great price on that butt! Where did you get it??
My local Kroger had them on sale.     I think the sale was due to another Texas based grocer, HEB, opening a new store close to Kroger.      I am hoping there will be some good meat sales coming in this Wednesdays add for the 4th of July.
 
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Here's a pic of my probe & sensor (the cleaned parts)
Looks like your Gen #2.5 still has the two sensors separate, like our older models, although in slightly different positions.

That's odd that Steve's has only the one sensor showing in his.

Bear 
 
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