Regulating Temperature Fluctuations - Masterbuilt Propane Smoker

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cosmoj

Newbie
Original poster
Apr 1, 2011
5
10
Hi Everyone - first time poster, and newbie smoker!

I am a long time griller and decided to get into Smoking - this is the best forum out there, IMO!

I smoked my first pork shoulder last weekend...   6.5 lbs, coated with Rub, 11 hours of smoking to reach internal temp 160F with Smoker temps on average 225-240, Hickory and Apple chunks, apple juice/Capn Morgan's spray once per hour...  Wrapped it in foil and moved it to the oven on 250F for another 3 hours to reach internal temp of 200F then wrapped in towels and threw in a cooler for 2 hours. About 16 hours total.  I tried a finishing sauce, but wasn't a big fan (think I'll keep it au natural next time) - all in all though, the result was fantastic! (pics below) 

After learning much from my first attempt with this smoker by doing Ribs the week before (and getting info from this forum), I had swapped out the factory wood chip pan for a cast iron skillet as the chips/chunks kept flaring up even when covered with foil, so problem solved there...  I had also bought the Maverick thermometer so I could determine the internal temp and get a more accurate gauge on the cabinet temp rather than solely relying on the factory door thermometer; awesome purchase, problem solved there... 

The issue however, was regulating the temperature on my Masterbuilt Propane Smoker...  It seemed like I had to adjust the temp knob on the Smoker constantly as I would have temperature swings of sometimes 50 degrees - I could literally watch the temp go from 225 to 205 to 250+.  Is this normal?  Is there anything I can do to avoid this and keep a more steady and even temperature?  The remote thermometer is great, but I'd rather not have to adjust the temp knob every 5 minutes in order to keep it between 225-240.  I kept water in the water pan...  I did notice that the temperature stayed a little more regular once I kept a new wood chunk in the pan for a longer time rather than replacing it with new chunks if I didn't see much smoke.  This also created a really thin smoke you can hardly tell was there - but the general consensus is that is the type of smoke you want... (yes?)

If anyone can give me advice on regulating the temperature of this Smoker I would be very grateful.  Any other general smoking advice is also much appreciated!

Thanks!

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First off welcome to SMF! Your PP looks excellent. As for the temp control issue, I can't help you with that since I have a charcoal smoker. There are a lot of guys on here with your smoker & one will be along soon to answer your question.
 
No, that is not normal. I literally can "set and forget", with a couple of exceptions. If your wood chunks catch on fire, then there will be some heat fluctuation. Are you using the stock water pan? In my honest opinion, I believe that it was way too small, especially for a pork butt. I went to smart and final and bought a full size deep catering pan and fill that sucker only one time on a 10-12 hour smoke. If you are having temp wings when you add more chunks instead of one, it leads me to believe that you are having some wood chunks catch fire. I use a cast iron pan and I still foil my wood chunks for added measure.

The only other thing that I can think of is if you have issues with a regulator or tank. One member here went through a couple of tanks before he hit the desired result. I hope this helps.
 
Thanks, dbarnett - I appreciate the troubleshooting advice!  I did foil my cast iron pan and didn't have the chunks catch on fire - I could tell because the "depleted" chunk was just a nice black piece of charcoal looking mass, instead of white ash (if it had caught on fire).  I will give that larger catering pan a try as I do agree that the stock water pan is pretty small...  I am smoking another Shoulder tomorrow with a new tank, so hopefully the fluctuations might have been that prior tank I used - sometimes when I had increased/decreased the temp knob it sounded like the gas volume escaping from the tank didn't increase/decrease accordingly, so maybe it was the tank(?).   I'll let you know how it goes for this next time around.

The amount of factors that go into this is pretty amazing - it's not as easy as throwing meat in the smoker and eating X hours later; there's certainly a craft to it.  But regardless of any growing pains I have had so far with Smoking, the learning, the doing, and especially eating the final product has been a lot of fun!
 
next time, try not to spray the shoulder down every hour.  every time you open the door all the heat escapes and takes longer to get back to temp to continue smoking. maybe try spraying every 3 or 4 hours.  i have a MES 40 and the only time i open the door is when it reaches 165 internal temp so i can foil it.
 
My model looks a little different from yours. My doors open from right to left. I did some mods to decrease heat & smoke loss by installing fiberglass rope around the lip on both doors. Made a world of difference in maintaining temps. I keep the bottom vents almost fully closed anf the top vent wide open. Having the bottom vents almost closed allowed the flame to stay mostly blue (desired) from the mostly yellow flame (bad) I was getting.  I have switched  from using water in the pan to a sand filled pan after reading many posts here on that detail. I also notice in one of your pics gease dripping down onto your bottom door. That could be causing flareups, just a thought. Being basically lazy I use a disposal aluminum pan under anything I smoke to catch drips. Since the pics in the link I have switched to the AMNS from Todd which can be put in the upper chamber, pretty much eliminating any wood fires. Hope this helps....here's the link on the mods....http://www.smokingmeatforums.com/forum/thread/104113/master-forge-vertical-gasser-mods  
 
next time, try not to spray the shoulder down every hour.  every time you open the door all the heat escapes and takes longer to get back to temp to continue smoking. maybe try spraying every 3 or 4 hours.  i have a MES 40 and the only time i open the door is when it reaches 165 internal temp so i can foil it.
Great advice.  I am definitely trying that route this time around - I ran searches on the forum for Spray advice and a lot of folks don't even do it.  I think not spraying, or spraying with less frequency, will certainly keep the temp constant.  And will certainly knock time off the overall smoke with not having to constantly lose and regain temp.
 
That's awesome, Willie - those are some sweet mods.  I especially like the wind stopper mod so I'll definitely look at something like that for the future.  I'll also research Sand in the water pan as well. 

The drips on the door are from opening the doors and pulling the meat out to spray - but if it is dripping like that when pulled out, it is most certainly dripping like that when in the Smoker.  I was counting on the water pan collecting those drips, but thinking about the stock water pan being too small I'll need to get something bigger to catch those drippings.

These are all greatthings to think about, Everyone - thanks!!
 
Great advice.  I am definitely trying that route this time around - I ran searches on the forum for Spray advice and a lot of folks don't even do it.  I think not spraying, or spraying with less frequency, will certainly keep the temp constant.  And will certainly knock time off the overall smoke with not having to constantly lose and regain temp.


while your shoulder is smoking, the dry rub that you applied makes a crust on the outside of the meat (aka bark) which creates alot of the flavor when the meat is pulled and mixed together.  when the meat gets placed in the foil (i double wrap mine) i tend to get alot about 2 1/2 cups of juice and some rendered fat in the foil when i unwrap it.  i usually place the juice in a plastic container and place it in the freezer til the fat becomes a solid chunk on top of the juice and i pull it off and toss it.  i put the remaining juice back into my pulled pork.
 
As others have noted, keep the door closed as much as possible, especially with thin walled vertical smokers.

One of the common errors in using propane is to over adjust.  The more mass you have in the smoker (water pan, food, heat sink), the more gradual the temperature swings will be.  You should get the feel for your smoker over time and know how much adjustment is needed for the amount/type of food, wind, temperature, etc.,. but if you overcompensate, you will be out there swinging the propane flow from one extreme to another.  It doesn't take much change in gas flow to go up 15-30 degrees.  My experience is occasional small adjustments lessen the number of times needing to adjust.

Windy and cloudy days can cause significant swings in thin metal vertical smokers.  If you protect the smoker from the influence wind and cloud/sun, you minimize the internal temperature fluctuations.
 

Any (appropriate) mass will absorb and then radiate heat which will help stabilize the temperatures.  On my GOSM, I added a 40# concrete heat sink to my lower rack and it made a huge difference in keeping the temperature stable, especially to bring the temperature back up after opening the door.  You can test this easily by putting one or two inexpensive patio blocks on a shelf.  If it helps on your smoker, use it.

A somewhat larger water pan should help stabilize the temperature in a vertical water smoker.  Water not only works by providing mass, but the slow conversion of steam will contribute to dampening temperature swings, it is one of the key design elements of thin walled uninsulated vertical smokers.  Too little water and it is ineffective and requires constant refilling - too much and you may not get the temperature up high enough as too much thermal energy is expended on converting water to steam, and with a hot enough burner you'll turn your smoker into a steamer.

I would suggest making one change each time you smoke and your observations will prove that the change is an improvement or not.  If it helps, you are on the right track, if not, you know that too.  Trial and error and an intimate knowledge of your specific smoker and mods is the very essence of the art of smoking.
 
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Thanks, dbarnett - I appreciate the troubleshooting advice!  I did foil my cast iron pan and didn't have the chunks catch on fire - I could tell because the "depleted" chunk was just a nice black piece of charcoal looking mass, instead of white ash (if it had caught on fire).  I will give that larger catering pan a try as I do agree that the stock water pan is pretty small...  I am smoking another Shoulder tomorrow with a new tank, so hopefully the fluctuations might have been that prior tank I used - sometimes when I had increased/decreased the temp knob it sounded like the gas volume escaping from the tank didn't increase/decrease accordingly, so maybe it was the tank(?).   I'll let you know how it goes for this next time around.

The amount of factors that go into this is pretty amazing - it's not as easy as throwing meat in the smoker and eating X hours later; there's certainly a craft to it.  But regardless of any growing pains I have had so far with Smoking, the learning, the doing, and especially eating the final product has been a lot of fun!
I just loooked at your picture of the smoker and realize that you have the regular size smoker. The full size water pan will most likely not fit in this unit. I have the wide XL propane smoker. You might want to try the 1/2 size catering pan instead.
 
Just a quick update - I put the Shoulder on at 1:42am; beautiful Colorado night, no wind at all...  With a new propane tank and not opening up the box to spritz, the temperature has been very consistant and steady - no serious fluctuations like before.   I've kept the stock water pan (for now) but have kept it full.    I think I've only had to adjust the temp knob maybe twice in the last 9 hours.  
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        Stalled at 156F for the last hour, but just made the move to 158F - 10:25am... 
 
Great for you!  If the shoulder turns out like the last one you rassled with, it's sure to be mmmmmm..........
 
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