Masterbuilt MPS 340/G ThermoTemp Propane Smoker Review

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Propane smokers have a reputation for being cheap and poorly insulated. I was excited to get my hands on the ThermoTemp MPS 340/G from Masterbuilt to see if it bucked this trend.

With promises of excellent temperature stability from the new thermostatic temperature control Masterbuilt have made some big claims.

I’ve been cooking on this smoker for the last few months, and in this review, I’ll be sharing all of my experiences, including the bad and the good.

Masterbuilt MPS 340/G ThermoTemp XL Propane Smoker
  • Accurate and consistent temperatures
  • Beginner-friendly
  • Easy to clean
  • Lack of a seal for the cabinet doors
  • Several cosmetic defects
Check Latest Price At Amazon

Overview & first impressions

This smoker is extremely simple to use and produces satisfying results. It provides very accurate and consistent temperatures with minimal effort. Clean-up effort is not too bad either.

The lack of a seal for the cabinet doors is noticeable as soon as the smoker begins to smoke. I don’t know how much this affects the overall performance of the smoker, but the more smoke that escapes through the door, the less smoke travels through the whole smoker cabinet.

Plus, there must be a certain amount of heat that is going to be lost as well. 

What I like:

  • Temperature accuracy and consistency – I consider within 5°F of set temperature to be outstanding!
  • Simplicity of use – Start the gas, hit the ignition, and set the temp. This smoker doesn’t get much easier to use. 
  • Clean up is easy – With exception of the back side of the grease drain area which I’ll cover more below.

What I don’t like:

  • Quality handling and finish of parts – Come one Masterbuilt, I know you can do better.
  • Lack of seal for the cabinet doors – There shouldn’t be a lot of smoke coming from the cabinet doors. This just seems like a gimme.  
  • Rear grease drain area – They would be much easier to clean if the flame deflector was removable. However this is not a big deal by any means. 

Despite it’s issues, the Masterbuilt ThermoTemp tops our list of the best propane smokers thanks to its excellent temperature accuracy, smoke flavor, and ease of use.

Unboxing and setup

I was very happy with the level of care Masterbuilt took in the packaging for this smoker. Most parts were individually wrapped with cardboard and plastic wrap. I looked but was unable to find any parts that had been damaged during shipping and transport of the smoker.

Masterbuilt MPS 340/G propane smoker packaging

This smoker took me 1 hr 10 minutes to assemble. This time also accounts for stopping to take a few pictures along the way. While most of this smoker went together quite easily, I did find a few of the instructions to be a bit tricky. There are a few things that can be easily overlooked.

Pay close attention to the following:

  • The black screws that install the temperature probe bracket. The screws that mount the temp probe bracket are different from the screws that install the probe wire cover brackets.
  • The smoke vent slider plate on the back of the smoker requires that the bracket be rotated 90 degrees in order to be installed.
Masterbuilt MPS 340/G smoker vent slider plate
  • Ensure that the brass gas supply tube sits inside the silver burner tube when installing the front smoker bracket that contains the brass gas supply tube. This may not seem readily apparent from the instructions initially.
Masterbuilt MPS 340/G smoker vent tube

Build quality

The smoker legs and bracing are quite sturdy.

I am disappointed to say that there were several part defects that were found that would have happened prior to packaging and shipping. I found a dented smoker leg, a poor weld on one of the door hinges, a bent sheet metal corner, and missing paint from the propane pre-assembled connections.

Masterbuilt MPS 340/G smoker cosmetic defects

All of these defects are cosmetic issues and would not affect the structural strength of the smoker so I did not bother going back to the manufacturer. 

Smoking on the Masterbuilt ThermoTemp XL Propane Smoker

I ran this smoker through a variety of smokes including chicken quarters, pork spare ribs, and Boston butts.

meat smoking inside the Masterbuilt MPS 340/G propane smoker

Using this smoker couldn’t be easier. There are no fancy bells and whistles. Just fill the water pan, open the valve on your propane tank, open the lower cabinet door, push the temperature valve in, hit the ignitor button, wait a few seconds, set your desired temperature. That’s it! If you’ve ever started a propane grill, this is no different. 

Masterbuilt MPS 340/G propane smoker wood bowl with wood chunks inside

When wood chips are used, they only last about 15-30 minutes in this smoker. Thankfully, this smoker can use wood chunks. The chunks tended to last about 1.5-2 hours and made using this smoker much more tolerable. 

After you start the smoker, open the wood bowl lid and drop a piece or two of wood chunks in there. In about 10-15 minutes, you will have smoke going and ready to load your meat. It’s really that simple. The smoker does the rest. 

Cleaning the smoker

Cleaning the Masterbuilt XL smoker is pretty straightforward. After cooking, most meat drippings either fell in the water pan or down into the bottom floor of the smoker.

Masterbuilt MPS 340/G smoker grease pan

The only thing that is a little bit of a hassle is trying to clean the smoker floor on the back side of the flame deflector plate. This could have really been made easier by designing the flame deflector plate to be removable instead of permanently installed to the floor. 

Temperature variance and accuracy

I was super impressed with the accuracy and consistency of the temperature inside the Masterbuilt XL smoker. Not only was the temperature accurate when compared to what the dial is set to, but it is also consistent over time.

Masterbuilt MPS 340/G propane smoker with open door and temperature probes inside

For example, when I set the smoker at 225°F, I checked this temperature in two different locations with my Thermoworks Signals, and both locations showed within 5°F of the set temperature.

And better yet, the temperature stayed within 5°F of the set temperature for over an hour without fail! This is extremely impressive no matter what fuel source we are discussing.

Final verdict

This is an all-around solid choice for a propane smoker. Sure, the quality could be a little better, but the structural strength of the smoker is more than adequate. If someone is looking for an entry-level smoker that is easy to set up and get smoking, this is it!

Do yourself a favor: if you buy this smoker, use wood chunks instead of wood chips. You’re welcome.

And while I personally believe the smoker should have a seal on the cabinet doors, a person could argue it may not be needed. Fortunately, if you think the same as me, this can be easily fixed. I actually purchased a fire seal from Lava Lock and installed it on the smoker doors myself.

Masterbuilt MPS 340/G ThermoTemp XL Propane Smoker
  • Accurate and consistent temperatures
  • Beginner-friendly
  • Easy to clean
  • Lack of a seal for the cabinet doors
  • Several cosmetic defects
Check Latest Price At Amazon

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