I’ve always thought vertical pellet grills don’t get enough love. You get way more cooking real estate in an efficent footprint that easily fits into a small deck or patio.

I recently got my hands on the new Grilla Grills Mammoth vertical smoker, and I think this might be the smoker that convinces everyone.

In this review I’ll run through my experience so far, including an epic 22 hour smoke.

Grilla Grills sent me this grill for free in exchange for an honest review. All opinions are my own.

First impressions of the Mammoth

It takes a lot for a pellet grill to impress me. As someone who started as a “stick burner,” I find that most pellet grills pretty much do the same thing. Add pellets, press the button, and smoke meat.

So, I get pretty excited when a grill like the Mammoth from Grilla shows up. I’ve cooked on a few different vertical pellet grills (e.g., Camp Chef XXL Pro and Pit Boss Copperhead), but the Mammoth impressed me before I even fired it up.

The entire body of the grill is made from double-wall insulation, which is fantastic for maintaining temperature throughout a long cook. The latch on the front is heavy-duty, and once the door is shut, you have zero issues with smoke escaping through the door or body of the grill.

This thing is heavy-duty. The thick walls & sheer size of the grill are unlike anything I’ve seen in a smoker at this price. It boasts 1600 square inches of cooking space over five stainless-steel racks and has a massive hopper that can hold over 40 lbs of pellets.

You can add up to five more racks to the grill to give you a total of 3300 square inches of cooking space! They weren’t playing around when they named this “The Mammoth.”

But, the thing that piqued my interest was their claim that the grill could run for over 48 hours at 250°F without having to add pellets… I’ll be honest, I wasn’t convinced that claim could be accurate – that is, until I did my first overnight cook on it.

Assembling and burning off the Mammoth

While this grill is a mammoth (no pun intended… okay, maybe a little bit of a pun intended), the assembly was surprisingly easy. The grill was pretty much assembled out of the box. We had to attach the legs, wheels, and small pieces on the outside. Then it was ready to add the grates and fire it up!

The instruction manual was easy to follow, and the assembly took about 30 minutes to complete. While you don’t need someone to help, I always find that an extra set of hands is nice to have when assembling a grill – especially one this big!

I was a little bummed out to find that the smoker didn’t come with a cover, but that’s not abnormal in the grill world, so no harm, no foul. You can get a cover from the Grilla website for $59.99.

Like most grills, the grill does not come pre-seasoned, so the manufacturer recommends letting the grill run around 400°F for at least 45 minutes to an hour to burn off any chemicals and residue left behind by the manufacturing process, but once that seasoning process was done, I was ready to start cooking!

What it’s like to cook on

When I fired the Mammoth up for my first cook, I decided I wanted to really put this grill to the test with an overnight cook. I figured that the only way to test if the pellet capacity was everything they claimed was to go ahead and run it for 24 hours straight.

I loaded the hopper with two bags bags of pellets to fill the full entire 40lb capacity and set it to run at 225°F. I added two pork butts to the grates, shut the door, and let it do its thing.

I was pretty shocked when I woke up the next morning (about 9 hours later) and found the hopper was still almost ¾ full of pellets. The amount of pellets that the grill burned in such a long time period was really impressive, but the pork butts were temping around 155°F internal so I was sure that the grill held a steady temp all night long.

One thing that I noticed about the grill that I don’t love is that it’s a little bit loud. While it wasn’t enough to get an angry text from my neighbors or anything, I could distinctly hear the grill running from inside my house. That being said, it’s a huge chamber, so it takes some power to keep the chamber filled with smoke and up to temperature so the noise makes sense.

I decided to wrap one pork butt and leave the other to smoke unwrapped so I could get a good gauge on the amount of smoke hitting the pork during the cooking process.

All in all, both pork butts took between 20 and 22 hours total, and when I was done cooking, the Mammoth still had 50% of the pellets remaining in the hopper. I could have easily continued to run this smoker for another day at the 225°F temperature.

Both the wrapped and unwrapped butts had amazing bark and beautiful smoke flavor. I got a solid smoke ring on both butts, and I was really impressed by the flavor the grill was able to pack into the meat.

I find sometimes that pellet grills can leave a lot to be desired when it comes to smoky flavor, but the Mammoth performed beautifully and gave me delicious, BBQ meat.

I’ve followed that cook with a smoked pulled ham that went for 16 hours and had similar results.

Is it hard to clean?

The cleaning process for the Mammoth is very similar to any other pellet grill. The vertical design of the grill does make cleaning pretty easy because you can start from the top and work your way down.

One interesting thing is that Grilla Grills actually recommends you line the bottom of the smoker with aluminum foil, which most manufacturers advise against. I assume that because this is a vertical smoker the foil won’t affect air flow in the smoker because you’re not covering the drip pan as you would in a traditional horizontal smoker.

The foil method is a great way to keep your grill clean and catch drippings. You can remove and dispose of the foil when it gets dirty instead of having to deep clean the grill as often.

They also recommend that you clean out the ash from the interior of the smoker after every 24 hours of total cook time. This can be done with a Shop Vac or similar vacuum cleaner.

I like to scrape off the cooking grates after every cook while the grill is still hot with a grill brush and that keeps them clean consistently as well.

Competitor comparison

As I mentioned before, I’ve owned & cooked on a couple other vertical pellet grills, so I wanted to take a second to touch on the big differences between the Mammoth and some of the other popular vertical pellet grills I’ve tried.

Camp Chef XXL Pro

The smoker I would most closely compare the Mammoth to would be the Camp Chef XXL Pro. I wrote a full review of the Camp Chef XXL Pro when it came out and overall, I really like that grill.

My biggest issue with the Camp Chef is the build quality. When compared to other smokers in their line up like the Woodwind Pro, the build quality just doesn’t live up to what I expected.

Nothing illustrates this more than comparing the insulation of the body of the grill. When I smoke meat on the Camp Chef, I find that a lot of smoke escapes through the door and edges of the body of the grill, whereas the Mammoth had practically zero smoke escape due to the double-walled insulation design.

From a build quality standpoint, I would say that the Grilla blows the Camp Chef out of the water. But, where the Camp Chef has a bit of an edge is the fact that you can add charcoal and/or wood chunks to the fire box during the cook, which is awesome to get an extra layer of smoke flavor.

Final Thoughts

Overall I think the Grilla Grills Mammoth is a great buy for anyone that needs a lot of smoker real estate. It’s well-designed and has fantastic build quality.

While it’s a touch more expensive than the Camp Chef we mentioned above, there isn’t another smoker on the market which I’ve tried that comes close that offers this level of size and build quality.

I was unable to get the app to connect to my WiFi and that was pretty disappointing. I would like to be able to use the app during long cooks especially. I believe the issue is with my WiFi setup, so I need to do some more investigation before blaming this on any issue with the grill. If I have any luck getting it connected I will definitely update this article accordingly.