Masterbuilt Gravity 800 temperature performance testing

[flippingeo]

Yup, that’s right. I cheated in my RT. I bought a Masterbuilt 800 because I needed something new to tinker with, and I’ve been missing smoke flavor. I won’t go into that aspect other than this thing imparts more smoke flavor than anything I’ve eaten from a pellet grill. Not hatin’, jus sayin’.

The TLDR;​

• The Masterbuilt 800 is far more consistent and precise across the pit than any pellet smoker I’ve owned. There will always be variances within a pit, and I’d consider these results to be acceptable, and in my experience, better than most.
• My reports/assumptions are based solely on the measurements from the Thermoworks Smoke, and 4 MEATER probes. However, I don’t trust MEATER fully. Unfortunately I didn’t have enough TW probes to keep it consistent. While I did record the lid and MB temps, I felt precision was in question so didn’t use them in the variance factoring.
• Findings/Assumptions
  • Middle rack (TW) - Generally runs a bit hotter than the bottom grates. At lower temps this was always within 10°. As pit temp is increased, this appears to be an exponential relationship resulting in nearly 45° hotter at temperatures 400° and above. Word of warning for those that consider this a “warming rack”. Might want to call it the “warmer rack”. Mean variance of +13.3°.
  • Bottom grates (MEATER)- Generally the right side of the pit runs hotter than the left. Not unexpected due to levelness of the smoker, and proximity to the firebox. Despite the level concerns, I feel safe in my assumptions that left is cooler.
    • M1 - Back/left was consistently the coolest location in the pit varying as much as 22° lower than target. It remained below target through all increments. Mean variance of -15.1°.
    • M2 - Front/left was cooler than target, but within 10° for every increment. This was true at least until I got to 350° to which it then read 10°+. However, this location was overall the most consistent with a mean variance of - >0.5°
    • M3 - Front/right was probably the most consistent spot at lower temperatures. However it trended higher variances as the target temp increased. Mean variance of +6.1°.
    • M4 - Front/left was about the same. There was one odd reading at 275°, which I can’t explain other than measurement device anomaly. In either case, mean variance of +1.1°
• I’ve included the spreadsheet of the measurements if you give a hoot.
• Other thoughts/opinions
  • Temperature rises like on this thing like lightening. Super fast changes compared to pellet. No more waiting around 15 mins for the smoker to go from 250° - 350°
  • MEATER+ is junk (personal opinion). I don’t recommend them for anyone, though I know a lot of people do. Too many points of failure and I’ve yet to get through a cook (or test) without them disconnecting, or returning bogus values. If they work for you, good stuff. But if you don’t have them and have been thinking about them, I’d suggest anything Thermoworks makes, or Fireboard.

The Equipment​

• Cooker - Masterbuilt Gravity Series 800; OEM Controller with LSS hopper mods and manifold cover.
• Fuel - Ol Blue Kingsford Briquettes
• Measurement-
  • 1 Thermoworks Smoke ambient probe mounted center on middle rack
  • 1 Aftermarket analog lid gauge (OEM doesn’t include temp values)
  • 4 MEATER+ probes mounted in onions for ambient readings in a quad fashion
    • 1 - Back left
    • 2 - Front left
    • 3 - Front right
    • 4 - Back right

The Process​

I allowed 30 mins for initial warmup with a starting temp 150. I would never cook/smoke at this unless I’m cold smoking some cheese, but it’s capable so wanted to try it.

I was going to go through the process of ensuring a level device. But all of my concrete is sloped for drainage so I wanted to test it as I plan on using it. Front to back it’s dead nuts. Left to right is definitely sloped down to the left. But based on how this thing manages grease this is preferred to move away from the from the fire box. Based on this, higher temps observed on the right were expected, due to slope and proximity to the fire box.

Measurements were captured 10-15 mins after the first probe reached the set target. The target temp was then increased based on the iterations listed below. Rinse repeat.

I had hoped to take the tests to close to 500° (limits of MEATER), but I was having so many issues with MEATER connectivity, and my onions were starting to fail (overcook) risking my probes tagging the grates… So I had to stop at 400°. I think that is ok as anything over that and your grilling and precise temp is not as important.

The Results​

These are listed below in the following order:

Set Target Temp​

• MBD - (Masterbuilt digital reading)
• TW - (Thermoworks Smoke ambient)
• MBA - (Masterbuilt analog lid reading)
• M1 - (MEATER probe 1)
• M2 - (MEATER probe 2)
• M3 - (MEATER probe 3)
• M4 - (MEATER probe 4)

---

150°​

• MBD - 150°
• TW - 155-158°
• MBA - ~155°
• M1 - 139°
• M2 - 144°
• M3 - 150°
• M4 - 156°

180°​

• MBD - 180°
• TW - 180-186°
• MBA - ~175°
• M1 - 164°
• M2 - 171°
• M3 - 179°
• M4 - 180°

200°​

• MBD - 200°
• TW - 200-208°
• MBA - ~192°
• M1 - 183°
• M2 - 191°
• M3 - 201°
• M4 - 200°

225°​

• MBD - 223°
• TW - 230-234°
• MBA - ~210°
• M1 - 208°
• M2 - 217°
• M3 - 224°
• M4 - 227°

275°​

• MBD - 275°
• TW - 280-283°
• MBA - ~245°
• M1 - 253°
• M2 - 274°
• M3 - 282°
• M4 - 263°

350°​

• MBD - 351°
• TW - 370-376°
• MBA - ~325°
• M1 - 335°
• M2 - 362°
• M3 - 359°
• M4 - 353°

400°​

• MBD - 399°
• TW - 440-446°
• MBA - ~393°
• M1 - 392°
• M2 - 418°
• M3 - 428°
• M4 - 409°

 

[charlesrshell]

Thanks for your review. I was hoping for less smoke. Does it act like a plain old charcoal grill? Does it have charcoal flavor to the meat?

 

[flippingeo]

So I haven’t run it without wood splits yet to be able to give you a firm answer. According to some, if you don’t load it with wood you’ll get little Smokey flavor. Now, whether that pivots to charcoal flavor, I’m not sure. Definitely worth a test. I would imagine it will render close to just a charcoal kettle.

 

[flippingeo]

I should clarify I haven’t run a cook without wood. This test was strictly charcoal

 

[sdynak]

Wow.. you certainly evaluated this very well. Nice writeup.

M4 is Back Right?

 

[flippingeo]

Wow.. you certainly evaluated this very well. Nice writeup.

M4 is Back Right?

Yes

 

[TexasBirdDog]

This is great info and very thorough considering the equipment you used.

However, I would argue that accuracy is most important in the smoking ranges(example; 225-275°). As temp variances in that range can more dramatically affect a cook. The variances at higher temps are less of an issue, and some could argue a non-issue, since those ranges are more used for grilling/searing where precise temps are not as necessary.

 

[flippingeo]

This is great info and very thorough considering the equipment you used.

However, I would argue that accuracy is most important in the smoking ranges(example; 225-275°). As temp variances in that range can more dramatically affect a cook. The variances at higher temps are less of an issue, and some could argue a non-issue, since those ranges are more used for grilling/searing where precise temps are not as necessary.

Agreed. And even stated that.

Even with just focusing on the lower temps I.e., 150-300, this thing is far more precise and consistent across the pit than my 590. I did a similar test with my 590 years ago, but never posted it. I was thinking about doing it again, though I might invest in a better ambient array and ditch the MEATERS.

 

[SmokeOCD]

Can we get a non biased shootout - I guess chef's choice.... ribs, shoulder, whatever; and give us head to head comparison of the same thing cooked on the two different grills/smokers/whatever.

I don't know that I care so much about accuracy, yes it's nice - but flavor after 6 or 12 hours is what matters to me more. Temp swings do provide some benefit to the cooking process. Rock steady adds to predictable cooks. Which one tastes better?

 

[flippingeo]

Can we get a non biased shootout - I guess chef's choice.... ribs, shoulder, whatever; and give us head to head comparison of the same thing cooked on the two different grills/smokers/whatever.

I don't know that I care so much about accuracy, yes it's nice - but flavor after 6 or 12 hours is what matters to me more. Temp swings do provide some benefit to the cooking process. Rock steady adds to predictable cooks. Which one tastes better?

It is my plan next weekend. I’m going to run 2 butts, one in each. Based on the food I’ve pulled off the MB… it will likely have more flavor. But I’ll have my guest tell me their opinion. Got some fellow smokers coming over, so I’ll keep it blind taste test.

 

[PrinceMike]

It is my plan next weekend.

I'd be very interested to see your results. I was thinking of doing the same thing. Truth is I haven't used the Recteq since getting the Masterbuilt.