From Commercial Freezer to Commercial Smoker

[Bumppo]

As part of our journey to get into the catering business, we sat down with a local brick and mortar operator and got a fair amount of advice. But the first thing he asked us when we started talking was "How big is your smoker?" I had always known I would eventually need to upscale, but I realized that in order to cater a large event, I would need to either do multiple cooks over multiple days, or use the four smaller cookers I have at the same time with different fuels and different results. It just wouldn't be consistent.

My first thought was to buy a larger smoker. But anything larger enough would just break the bank. And then I started looking for old tanks to build a large offset or vertical smoker. Even those prices were more than I was wanting to pay. Not to mention that now I would have to teach myself how to weld.

So I was looking around the forum for some ideas and found some of the older commercial fridge builds and figured that would be a good place to start. After a long search and a few failed contacts, I found this one for $100. It was about 50 miles away, but I had a jobsite to visit in the area. So I was able to keep myself on the clock while I went to pick it up. So technically, I'm still ahead on the cost!

At this point, the rough plan is to strip everything out, including the aluminum liner and insulation, and replace it. I'm going to use rock wool for the insulation and whatever thinner gauge steel sheeting I can find. I don't think its going to need to be too thick, since I'll have the rock wool.

One thing I would like to do with this is to build a removable center wall. I think it would be nice for smaller cooks to only have to burn fuel for half of it. Or maybe even potentially run the two side separately, depending on what I'm cooking and how I'm heating it.

I'm still on the fence for what I'm going to use for both heat and smoke.

I know when it comes down to temperature control, the easiest thing to do would be to go with electric. But I already know that I'm going to have at least one large event per year that is completely off grid. The size of the generator I would need to run the heating element(s) might just not be practical to bring along on trips like that. My original idea had been to use a propane burner with a thermostat. I still like that idea. But I'm open to suggestions.

I'm also having a hard time deciding what to do for smoke. I know the easiest thing to do would be just get a pellet maze and not have to worry about it. Or just do chips in a tray over the burner. But I love the taste that comes from the charcoal and wood in the offset, and I really don't want to lose that flavor profile. So my first thought was an exterior fire box. I would get smoke and some heat out of there, and use the main controlled heat source to regulate it. I figure I have two options here. I could buy one of those small woodstoves that people use for backpacking and just pipe it in. Or mount an aftermarket firebox made for a OK Joe or Char-Griller offset and use that. It would still take some regular tending to keep the TBS where I want it, but having a regulated heat source inside the main chamber means I wouldn't have to worry about temp swings.

I'm also open to other options. For example, I'm going to look into gravity fed options that can handle wood chunks. If this turns out to make sense, I might eliminate the electric element or propane burner all together. Not really sure. This is coming to me as I type this.

But I'm definitely open to open to any suggestions anyone might have. Life can be busy, so I'm expecting this to be a long build. Until I get the interior re-done, everything is up in the air.

 

[Bumppo]

We actually started the demo yesterday, before I made the intro thread. I went outside to just stare at it and brainstorm, but somehow ended up with a screwdriver in my hand, instead.

We basically removed everything that wasn't screwed or bolted down. And started tearing out the aluminum liner. From the other builds I've read, I'm expecting to be very miserable once we start ripping out the old insulation.

 

[SmokinEdge]

That would be a cool setup as a gravity feed. But what ever way you go if you divide it you will need 2 heat sources. Maybe if you divide it you use the other side as a warming cabinet, that would be much simpler to do.

 

[Bumppo]

Thats a really good point! I had thought about potentially needing double the heat source, If I were to go that way. But in reality, I can't really think of a good enough reason to need to run at two different temps to justify the expense.

The removable divider was going to be well insulated. But your suggestion to use the empty side as a warmer is making me think I'll want to play with different thicknesses to see what will work best. For example, if the cook chamber is 250-275, what do I need to do to keep the other side at 140-150? You just added another fun puzzle to this build!

Your idea is also really practical. My initial figuring tells me that this thing will be able to easily feed 200+ people from one cook. But I'm willing to bet that most of the events I'll do while I'm first starting in the business will be for half that number at the most. So I will usually have a built in warmer.

 

[tallbm]

As part of our journey to get into the catering business, we sat down with a local brick and mortar operator and got a fair amount of advice. But the first thing he asked us when we started talking was "How big is your smoker?" I had always known I would eventually need to upscale, but I realized that in order to cater a large event, I would need to either do multiple cooks over multiple days, or use the four smaller cookers I have at the same time with different fuels and different results. It just wouldn't be consistent.

My first thought was to buy a larger smoker. But anything larger enough would just break the bank. And then I started looking for old tanks to build a large offset or vertical smoker. Even those prices were more than I was wanting to pay. Not to mention that now I would have to teach myself how to weld.

So I was looking around the forum for some ideas and found some of the older commercial fridge builds and figured that would be a good place to start. After a long search and a few failed contacts, I found this one for $100. It was about 50 miles away, but I had a jobsite to visit in the area. So I was able to keep myself on the clock while I went to pick it up. So technically, I'm still ahead on the cost!
View attachment 722265View attachment 722266

At this point, the rough plan is to strip everything out, including the aluminum liner and insulation, and replace it. I'm going to use rock wool for the insulation and whatever thinner gauge steel sheeting I can find. I don't think its going to need to be too thick, since I'll have the rock wool.

One thing I would like to do with this is to build a removable center wall. I think it would be nice for smaller cooks to only have to burn fuel for half of it. Or maybe even potentially run the two side separately, depending on what I'm cooking and how I'm heating it.

I'm still on the fence for what I'm going to use for both heat and smoke.

I know when it comes down to temperature control, the easiest thing to do would be to go with electric. But I already know that I'm going to have at least one large event per year that is completely off grid. The size of the generator I would need to run the heating element(s) might just not be practical to bring along on trips like that. My original idea had been to use a propane burner with a thermostat. I still like that idea. But I'm open to suggestions.

I'm also having a hard time deciding what to do for smoke. I know the easiest thing to do would be just get a pellet maze and not have to worry about it. Or just do chips in a tray over the burner. But I love the taste that comes from the charcoal and wood in the offset, and I really don't want to lose that flavor profile. So my first thought was an exterior fire box. I would get smoke and some heat out of there, and use the main controlled heat source to regulate it. I figure I have two options here. I could buy one of those small woodstoves that people use for backpacking and just pipe it in. Or mount an aftermarket firebox made for a OK Joe or Char-Griller offset and use that. It would still take some regular tending to keep the TBS where I want it, but having a regulated heat source inside the main chamber means I wouldn't have to worry about temp swings.

I'm also open to other options. For example, I'm going to look into gravity fed options that can handle wood chunks. If this turns out to make sense, I might eliminate the electric element or propane burner all together. Not really sure. This is coming to me as I type this.

But I'm definitely open to open to any suggestions anyone might have. Life can be busy, so I'm expecting this to be a long build. Until I get the interior re-done, everything is up in the air.

Hi there and welcome!

This is a cool project. I don't have any real help from building a smoker like this or figuring things out for a catering operation but I can tell you that I have done tons of work on the MES 40 inch models (Masterbuilt digital Electric Smoker) which might translate a little for your project.

When it comes to an MES they use pretty thin stainless steel sheet metal so you don't have to go crazy. I don't think it's over 1/16th of an inch thick, if even that.
They use a liquid/spray foam insulation to give the body of the smoker it's rigidity and sturdiness and wow does it do that well BUT, that foam is not rated to work at temps of 300F for too long so they make the controller only go up to 275F and most MES units I've had or know of rarely even hit 275F at the sensor.

With that said, your insulation will be great for temp holding but if you need stiffness you will likely have to mount some "rails" from top to bottom of your walls to which you can fasten your thin sheet metal walls to. It would also be wise to measure and pre-bend your sheet metal so you can jimmy it in and just slide in place if possible, but whatever works to get a good wall up can be done.

As for halving it that is a great idea.
Something to think on is that you can "halve" it horizontally as well using removable "shelves" that basically cut down the volume of the smoker.
In my MES I often only the lowest or bottom 2 racks, rarely 3 racks or the whole thing. So these leaves a lot of open volume in the smoker above the area where my food is cooking.
My solution was to cut an untreated birch wood sheet to make a "shelf" that I slide on TOP of my wire rack holder.
So if I'm only using the bottom rack I put the "shelf" on the wire rack holder above the food and that shelf helps keep heat trapped instead of it just rushing up immediately to the vent!

The shelf has many a 1/8th inch gap of contact between itself and most of the walls due to not trying to be precise with my cuts. This allows smoke to escape with no issue at all. My efficiency is and temp management is greatly improved with this. Why burn up more electricity than I need to right? :D

I think it's worth considering this as an option if you only want to use the lower 1/4 of the smoker left to right. Hell you can do both and design to vertical and horizontal flexibility but think of the efficiency and energy/fuel savings you get when you can cut down the space you are really trying to heat vs heating up all the extra empty space.

One last thing to think of. When doing poultry (chicken or turkey) the skin wants to be tough and rubbery unless cooked at high enough temp or doing a number of extra things to prep the skin. At a smoker temp of 325F I always have edible skin most of the time that wonderful crispy skin. Whatever heat source you land on make sure you can hit all the temps you need for what you will be catering with.
If you have strong temperature control and consistency from low temps (110F) all the way up to normal cooking temps, you can expand your operation into things like doing bacon, sausage, and jerky.
If you live in an area of the country that actually gets cold (I live in TX so not my area lol), you could even do cold smokes and things like Salmon Lox.

People always love bacon and if you can cater AND offer up small batch bacon "from scratch" you have a product in demand all the time, but your smoker has to be able to manage the temps for doing bacon without melting out fat if you cannot go pure cold smoke on it.

Well that is about all that's on my mind and hopefully some of it helps since I've done a ton of work on smaller electric smokers that have a lot of the same characteristics as your big fridge there :D

 

[Bumppo]

I'm planning on making an interior frame out of angle iron to give the skin some rigidity. Once I get the rest of the foam out of there, I'll have a better idea of how that will go together.

I definitely want to make sure this is able to hit temps of at least into the 325 range. I'm used to cooking at least 275 in warmer weather, with spikes a lot higher. SO I don't want anything to do with that foam when it gets hot.

I've actually used that shelf method on my first smoker build. The thing worked the way it was supposed to, but it went through way too much charcoal on long cooks. So I added a shelf, like you're talking. It was made out of wood, so I only had the courage to use it for one season before retiring it and moving to a couple Webers and currently a small offset. I agree with you're thoughts on bacon and sausage, and thats what this one is destined for in the near future.

 

[normanaj]

This will absolutely be a project to follow.

 

[JckDanls 07]

So another configuration to consider... As SmokinEdge suggested as half being used for a warming box... I'm not sure I would need a whole half of the smoker for trays/hotel pans of meat to keep warm... I don't think I would have that many trays/hotel pans... I would think just the top half of half would be plenty.... You could put it's own door on it INSIDE of the smoker and not have to alter the outside door... Adjustable ventilation to heat from main smoker... No second heat source needed... holding shelves/grates only need to be about 6"+/- apart Maybe have the bottom one a little bigger for whole meats...

Whatever you end up with for heat source... It's gonna take a substantial amount more than a basic smoker... If charcoal/wood chunks flavor is what you prefer then obviously you'll need to go gravity fed or a stick burner...

I'll ride along at the back of the line and keep an eye on progress...

 

[mneeley490]

Here's a link to the one I made years ago. Hopefully you can avoid the trials and tribulations I encountered.

Commercial SS Fridge Build: My First Try

Well gentlemen, I think it's time to post a few pics of my build, since it is very close to completion I started this in June when I bought a large, single door, Viking commercial SS fridge for $200. Sitting on its wheeled stand, it is over 6' tall. Seemed like bargain to me, compared to what...

www.smokingmeatforums.com

 

[Bumppo]

So another configuration to consider... As SmokinEdge suggested as half being used for a warming box... I'm not sure I would need a whole half of the smoker for trays/hotel pans of meat to keep warm... I don't think I would have that many trays/hotel pans... I would think just the top half of half would be plenty.... You could put it's own door on it INSIDE of the smoker and not have to alter the outside door... Adjustable ventilation to heat from main smoker... No second heat source needed... holding shelves/grates only need to be about 6"+/- apart Maybe have the bottom one a little bigger for whole meats...

Whatever you end up with for heat source... It's gonna take a substantial amount more than a basic smoker... If charcoal/wood chunks flavor is what you prefer then obviously you'll need to go gravity fed or a stick burner...

I'll ride along at the back of the line and keep an eye on progress...

Just so I'm understanding right, are you suggesting an enclosed box inside of the main chamber to use as a warming cabinet?

I definitely don't want the warming area to be a permanent part of it. My thought process is just to take advantage of the dead space that would come from putting up the temporary partition for the times when I won't need the entire chamber. For me, its more of a bonus feature than a key part of the design. I know I'll rarely need to utilize all the space for cooking right away, but as the business grows and evolves, I'd expect to start to need it more and more.

 

[Bumppo]

Here's a link to the one I made years ago. Hopefully you can avoid the trials and tribulations I encountered.

Commercial SS Fridge Build: My First Try

Well gentlemen, I think it's time to post a few pics of my build, since it is very close to completion I started this in June when I bought a large, single door, Viking commercial SS fridge for $200. Sitting on its wheeled stand, it is over 6' tall. Seemed like bargain to me, compared to what...

www.smokingmeatforums.com

Thanks. I've actually read through your build a few times already. Its really impressive!

On one hand, I got lucky that the existing lining in mine isn't really usable for the end product. So demo is going to be a lot easier for me. But it sure would be nice to have a ready made liner to put back into it.

Minor details like your door seal have definitely stayed with my in my head, though.

 

[Bumppo]

So at his point, I'm really leaning heavily toward the idea of going gravity fed. It really feels like its the only way I'm going to check all the boxes with flavor, consistency, and a set it and forget it option.

But it really doesn't seem like there are any options out there for an off the shelf unit that I can just purchase and add to the build. So unless anyone knows of anyplace, it looks like I'm going to just have to keep reading up on it and figure it out. Is there a calculator out there somewhere, like there are for offset builds, that can point me in the right direction for sizes? At a maximum, there will be about 36-37 cubic feet of space in the cook chamber. Half of that when the partition will be up.

 

[Bumppo]

Also, every gravity smoker I've seen online so far has had the hopper and firebox inside an enclosure, whether its a homemade build or from a manufacturer. Is this just for aesthetics, or is heat retention the bigger issue?

 

[processhead]

Your cabinet looks like it would be a great basis for a smoker.

If I was a commercial enterprise like a catering business, I would be looking for a smoker design that required the minimum amount of supervision. As a caterer, I suspect you will have a lot of irons in the fire, and minding a wood or charcoal fired smoker might require time that you may need for other business tasks.

I would also be looking for a well regulated heat source so your product was consistent from batch to batch. Customers like consistency, and with wood or charcoal heat sources, you need some pretty good controls that may be more difficult with a do-it-yourself smoker build.

An electric heat and PID controls with step temperature schedules would be something I would suggest you look into, along with a stand alone smoke generator

 

[Bumppo]

I think a properly built gravity rig would still give me the hands off convenience I'm looking for, but there a lot of cons that are running through my head. There are so many that it might not be practical.

I agree that an electric element with a controller is definitely the most foolproof method of maintaining a constant temperature. There will still be some huge drawbacks, like providing the actual electricity, but I'll consider that. My main concern is changing to a different smoke source. A wood/charcoal mix is as big a part of my flavors as my rubs are.

Its very fresh in my head and not at all thought out, but here is my new idea. I'm thinking about using expanded steel to build a sort of charcoal version of a pellet tray. The heat would be low, yet consistent. And the electric element and controller would keep me where I would want to be. But the big thing is that I would be able to basically run the same snake method that I used to learn how to cook and develop my recipes.

Does it make sense? Or am I dumb?

 

[JckDanls 07]

You can absolutly do that... Keep your charcoal/wood heat lower than your SP (set point)... Let the electric hold it where you want it...

We had to do sortof the same thing only in the middle of the cook... I hade double elements in the smokehouse and one burnt out.. So we supplemented with propane... held at temp with the limping electric...

 

[dward51]

If you have a multi-tool, put a flat scraper blade in it and the insulation removal will be much easier. Just run it up against the stainless outer shell and peal it up in long strips cut by the multi-tool. It will also take out most of the adhesive they used.

 

[Bumppo]

If you have a multi-tool, put a flat scraper blade in it and the insulation removal will be much easier. Just run it up against the stainless outer shell and peal it up in long strips cut by the multi-tool. It will also take out most of the adhesive they used.

I'm going to try it with just a putty knife first, but it looks like I could get a cheap multi tool from harbor freight for under $20. If the putty knife doesn't work the way I'm hoping, that might be a smart in investment.

 

[Bumppo]

So with the idea of an electric element, and my lack of knowledge, I'm wondering if cannibalizing a used oven off marketplace makes sense. Everything is already there. The element, wiring, thermostat, know, and all the hardware. I would just have to swap out longer wires. For a price range of free to $50, it makes sense, if its gonna work.

 

[JckDanls 07]

So with the idea of an electric element, and my lack of knowledge, I'm wondering if cannibalizing a used oven off marketplace makes sense. Everything is already there. The element, wiring, thermostat, know, and all the hardware. I would just have to swap out longer wires. For a price range of free to $50, it makes sense, if its gonna work.

The elements will work as that is what I use in a bigger smokehouse... The thermostat, not so much as it is a relay switch controlled ... meaning the heat is ether on or off so it goes by average... So it will have spikes (20-30 degrees above set point)... and drops (20-30 degrees below set point...

PID controller with an SSR is going to be the way to go... This set up will hold it dead steady at the set point... With only a 1-2 degrees swing...