E-Smoker Newbie - MES JMSS

Discussion in 'Electric Smokers' started by dejecklin, Sep 12, 2016.

  1. dejecklin

    dejecklin Newbie

    Good morning!

    I'm hoping one of you seasoned smokers can help us out!

    We bought our first smoker over the weekend. It's a Masterbuilt JMSS. 



    Anyways, we got it together, seasoned it as we were told. Given the time of night, we thought we’d start with a couple of burgers. Preheated to 225. Put the meat in and inserted the meat probe. So primarily, we noticed the temperature fluctuating quite a bit. It would go up to 235 and then drop back to 225, or drop lower. Then it would heat itself back to 225. 

    We would close the damper and it would hold the heat a little bit more consistently. Internal meat temp we were going for is 160. We finally got frustrated and pulled the burgers at an internal temp of 152.

    So my first question is this - Is this fluctuation in smoker temp common? I've read that some are setting the temp higher than the advised temp just to get it where they want it.

    Secondly, I'm seeing a lot of people using a Mav 732 to regulate internal meat temp? Is this the preferred method?

    I've seen lots of posts across multiple forums on not trusting the smoker temp or the internal meat temp. It seems like jacking the temp up and  using your own meat thermometer seems to be the method. Wondering if this is just a Masterbuilt issue or if it's one of those, across the board E-smoker issues.

    Any advice would be appreciated, as we're really just beginning! Thanks!!

  2. smokinal

    smokinal Smoking Guru Staff Member Moderator OTBS Member ★ Lifetime Premier ★

    Your electric smoker works like an oven it will fluctuate as the element turns on & off.

    If you have wood chips in it & it's smoking then leave the top vent open.

    Yes most use a Maverick or other temp gauge to monitor both the meat & cabinet temp.

    Most factory therms are way off.

    Would you swing by "Roll Call" & introduce yourself, so we can all give you a proper welcome to SMF!

  3. dejecklin

    dejecklin Newbie

    Thank you so much! We were feeling a bit disheartened! I've ordered the Mav 732. We'll give it another go! Have a great one!

    Dan & Erica
  4. sigmo

    sigmo Smoking Fanatic

    Since these smokers generate the smoke by heating the chips with the electric element, they have to cycle the temperature up and down. The chips smolder when the heating element is on, and then don't smolder much when the heater is off.

    So the heater serves two purposes. It maintains the temperature you've set and it burns the chips.

    So they are designed to leave the element on for quite a while when it kicks on, and of course that means it must stay off for quite a while when it goes off.

    In control system work, we refer to the temperature difference between when a heater (or cooler) switches on and when it switches off as "hysteresis".

    With some systems, you can set things up to have little or no hysteresis, which results in tighter, smoother, more constant temperature regulation.

    But many systems cannot operate without some hysteresis, so the temperature must fluctuate up and down.

    Refrigerators and home air conditioning systems, for example, must cycle up and down quite a bit because you cannot turn the chilling compressor on and off rapidly. When the compressor shuts off, time must be allowed for the gas pressures to equalize and the fluid to get where it is supposed to be before you turn the compressor on again, or the valves can be ruined.

    Likewise, many home furnaces which are either fully on or fully off must be operated with several degrees of hysteresis because it is wasteful and hard on the system if it cycles on and off too rapidly.

    Older home ovens have quite a bit of hysteresis, too, because of the way their thermostats operate. Again, the designers try to limit how often the heating element cycles because they want to increase the life of the component that swithces power to the heating element. These mechanical contacts wear a bit with each cycle.

    And with a gas oven that is either fully on or off, the life of the gas valve must be considered.

    As a result, the temperature in an older oven can cycle up and down by 25 degrees or more during normal baking. This is OK.

    Modern electric ovens can now use solid state relays to control the power to the heating element and throttle that power to provide almost infinite "proportional control" over how much heat is applied. That can allow extremely precise temperature control with little or no temperature cycling.

    But, if the maker of the smoker used that kind of control, the chips would never burn except at the very first, when the smoker was initially heating up. After that, the power to the heater would be throttled down to just what was necessary to maintain the desired temperature, and that means that the heatimg element would never be hot enough to make the chips smolder.

    So even though the manufacturer could give you tighter temperature control, they dare not do it that way or they would need to provide a separate method of generating the smoke.

    Many of us have gone to using separate smoke generators for oir smokers in order to separate tje temperature control from the smoke generation so we can control bot things better. But this adds some complexity and "tinkering" to things.

    Then again, lots of us enjoy tinkering! :)

    Welcome! And happy smoking. It's just a lot of fun, and there are a lot of experts on here to help. I learn things every time I get on here. And this site has made it possible for me to make a lot of great meals.

    Tabbed in.
  5. crankybuzzard

    crankybuzzard Smoking Guru Staff Member Moderator OTBS Member SMF Premier Member

    Once you get it dialed in, you'll love the smoker!

    Like Al said, the temp is usually way off on these things, but the Maverick will tell you what's really going on inside of it.

    Show us some cooks once you get rolling.
  6. sigmo

    sigmo Smoking Fanatic

    Also, remember that the placement of any temperature probe will give you astoundingly different temperature readings in most ovens because the air is not actively stirred. Place ten different sensors in various places, and you'll get ten different readings.

    People are shocked to see how wide the variations are from one place to another even in laboratory ovens. It's good to consider these wide variations in temperature when cooking in any oven.

    To judge the accuracy of any temperature instrument, you must thermally couple the sensor for the device under test (DUT) to the reference sensor and you must hold the temperature constant to account for the different thermal time constants of the different probes. Simply placing two probes near each other in air is highly inaccurate.

    And even if well coupled, in a system whose temperature cycles up and down, the speeds of response of each sensor will create different readings at any given moment in time, making it almost impossible to make valid comparisons.

    If you graph the readings from the two over time, you may see that their average readings are the same, yet taking any one pair of readings at the same moment, they may disagree wildly.

    All of this makes it very hard for us to come to valid conclusions about the temperature readouts and controllers in these smokers. Most people have no way to thermally couple an accurate temperature probe to the controller sensor in one of these smokers, let alone a way to log and graph the readings from both over time.

    Of course that doesn't mean that these smokers are accurate or that it isn't good to use a separate, trusted temperature measuring system! It's just that we have to be careful of how we use and interpret what we see from any temperature measuring setup.

    I wish it were simpler, but it really is disappointingly complex. :)

    Tabbed in.

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