How to Turn an Old Fridge Into a Cold Smoker
Cold Smoking Is Cooler in a Fridge
Have you ever wondered what to do with your old fridge that's just been sitting around waiting for disposal? Before you decide to get rid of it, you may want to stop and think about potentially converting that old appliance into a smoke cabinet.
I had a tall, old fridge that I earmarked for turning into a smoker from the day it stopped working, but I only recently had enough spare time to start work on converting it to a smoke cabinet. Fortunately, the payoff was well worth the work, and the cold smoker came out great! This article is a look at how I turned my old, broken fridge into a cold smoker and is intended to provide inspiration to those looking to begin (or continue) cold smoking food.
Due to the nature of the project, I decided that it would be best to try to work on as low a budget as possible to keep the cost of the build well below that of models on the market that are specifically built for cold smoking.
Secondly, I wanted to keep the complexity and tool requirements as low as possible, so that anyone who likes smokey deliciousness and has an old fridge handy can turn their hand to greatness.
An Old Fridge? Really?
Fridges are large, well-insulated spaces that are sealed and perfect for holding smoke. They keep internal temperatures constant, and perhaps best of all, they are really easy to come by.
From Fridge to Smoke Cabinet: An Overview
This section will detail the steps I used to convert my fridge. It is unlikely that you will have the same model of fridge, but all the same principles apply to any fridge type. I have tried to keep the budget to a minimum, but you can be as frugal or as lavish as you wish. A rough outline of the process is as follows:
Time Required: ~10 hours
- Clean the fridge. (Don't forget the inside of the door like I did first time 'round.)
- Decide intervals for shelving/hanging.
- Cut and attach slats to allow fitting of removable metal rods.
- Cut metal rods to size in desired quantity.
- Create and fit the chimney.
- Apply sealant to any gaps or holes.
- Fireproof bottom of fridge for use with smoke generator.
- Install thermometer(s) to allow monitoring of internal temperature.
- Do a final cleaning and smoke test.
Tools You'll Need for Building a Smoker
Drill (cordless is ideal)
Drill bit for wood — 6 mm
Stanley knife (or similar)
Drill bit for metal — 6 mm
Hacksaw (12-inch with metal cutting blade)
File (for metal)
15 mm circular cutter
Tin snips (metal shears)
Center punch or robust nail
Materials You'll Need
Paint (I used Hammerite)
Bolts — 6 mm (long enough to go through the fridge wall and slats)
Wooden slats (I used a few old bed slats)
Nuts and washers (to fit bolts)
Iron/steel rods — at least the width of the inside diameter of your fridge (I cut mine from an iron gate)
BBQ/smoking thermometer (long stem, about 5 inches)
1–2 feet of steel pipe — 30 mm diameter (~1.5 inch)
Steel sheet for fireproofing bottom (optional depending on smoke generation type)
Important Safety Information Before You Start
Fridges are able to maintain their low temperatures by pumping refrigerants through a heat exchanger.
There are a few types of refrigerant, but it is inadvisable to cut any pipes or try to remove any of the heat pumps or heat exchange tubing from the back of the fridge. A cold smoker will not reach temperatures that risk the refrigerant leaking out, so it is best to leave it all well alone.
If you do accidentally damage the pipes and refrigerant begins to leak out, make sure the fridge is in as well-ventilated an area as possible, and do not breathe any fumes. If you're inside, open windows and leave the room. Refrigerants can be bad for both you and the environment and should be treated carefully.
A lot of useful information regarding refrigerant can be found in this helpful guide from The National Archives.
(Note: Most fridges are lined with plastic and are not suitable for hot smoking, where temperatures are much higher. Do not attempt hot smoking in your fridge!)
Step 1: Clean the Fridge
The fridge I used had been outside for some time and had become a bit . . . well . . . green on the outside and had some snail lodgers on the inside. I turfed out my unwanted guests and set to work with warm soapy water and a hosepipe. In no time, my fridge was good as new.
Let your fridge dry before moving on.
Step 2: Choose Where You Want Your Shelves
My aim was to create a smoke cabinet that can be used for a variety of smoking applications, including hanging large joints centrally from meat hooks, or for fish or cheese on horizontal racking.
First, measure the internal dimensions of your fridge and have a think about where you would like shelves. The next few steps will detail how to achieve the design shown in the picture of this step.
Step 3A: Cut Slats to Allow Fitting of Removable Metal Rods
Once you have decided how many shelves you would like and how much hanging space you want, it is time to work on the slats.
Start with the central slat, which will be the longest of the three, and draw horizontal lines (with a steel rule or setsquare) where you want the base of each notch to be. This way, you ensure level racks.
Once you have marked all the rack heights, measure the intervals between them and mark off these same intervals on the shorter slats.
(Note: For me, the central slat has an additional top notch that does not align with the shorter slat notches. This is a notch for a single bar for hanging only.)
Once you have each slat marked out, you can cut the notches (see picture below).
I used a coping saw while holding the slats in a bench vice. Make sure that the notch is a little larger (though not too much larger) than the width of the metal rods that you will be using so that they are a snug fit.
Step 3B: Attach the Slats
To attach the slats, you will need to lay hands on a drill (cordless is ideal), as well as a drill bit for wood and a drill bit for metal of the same size. (I used 6 mm bits for both.)
I placed the central slat first into the position that I required. After making sure that the slat was perpendicular to the fridge (vertical), I marked the locations to be drilled using a center punch and a small hammer.
I then drilled the marked holes with the relevant drill bits (metal for metal and wood for wood) and attached the slats using 6 x 80 mm coach bolts with the head inside the fridge and the nut on the outside.
In the picture below, you can see that the bottoms of the notches are vertically aligned so that the shelves are level. Make sure to get both sides lined up before you attach anything too securely.
Step 4: Cut Metal Rods to Size in Desired Quantity
Using a hacksaw (or angle grinder with a metal cutting disc), cut the metal rods to a length approximately 10–15 mm shorter than the internal width of your fridge.
File the ends to round off the edges and to remove any burs or sharp bits. I cut eight rods, three sets of two for horizontal shelves/racks and two rods (slightly thicker) for central hanging.
IMPORTANT: Please wear adequate safety protection, as metal filings in your hands or eyes are decidedly not fun!
Step 5A: Create the Chimney
At this point, you should have something that is beginning to resemble a smoke cabinet.
It is time to fit a chimney for the smoke to escape slowly so that it does not get stale in there. The chimney should not be too large though, or there will be too much of an air exchange.
I found a suitable piece of pipe that was mild steel and had been part of a shower rack that was no longer in existence. I cut a section of pipe about 1 1/2 feet long, sanded the rust off, cleaned it and then painted it with black Hammerite (a paint for metal).
There are several ways to cut a hole in metal. If you have a circular cutter of the correct dimensions for your pipe, then this should do just fine.
I did not have the right tool for cutting a circular hole in metal. So, I opted for a much cruder method of repeatedly piercing holes in the metal with a nail in a circle of the desired diameter. Be careful of sharp edges if you do this.
Step 5B: Make an Aligning Hole for the Chimney
Making an aligning hole beneath the first hole may be tricky, but it depends on the lining of your fridge.
I removed some of the insulation uncovered by the first hole and forced my soon-to-be chimney down until it was pressed against the inner liner of the fridge. (Twisting helps with this.)
Step 5C: Fit the Chimney
Fit your chimney so that it protrudes a little way into the inside of the fridge—2–4 mm would be fine—leaving enough pipe to be able to put sealant around later.
You may need to apply a second coat of paint if you scratched it during fitting, as the paint will protect your chimney from rust, making it last longer.
Step 6: Apply Sealant to Any Gaps or Holes
Use a sealant gun to add silicone around the holes that you cut (top and bottom) to prevent unwanted leaking and to ensure that no creepy crawlies will be able to make their way inside between uses.
Step 7: Fireproof the Bottom Portion of the Fridge
Your smoke cabinet is almost done.
Depending on the construction of your fridge and how you are planning on generating smoke, it may be necessary to fireproof the bottom portion of your fridge, even though most smoke generators don't produce much heat.
For me, this involved lining the bottom of the fridge with some sheet steel and including a raised rack to dissipate any heat.
(Sadly, I don't have any pictures of this step, as my camera battery died.)
Step 8: Install Thermometers
Cold smoking must occur within a reasonable temperature range of about 10–32 degrees Celsius (50–90 degrees Fahrenheit). So, it is strongly recommended that you install at least one thermometer into your smoke cabinet.
There are several types available, but I opted for two long-stem thermometers from to go through my fridge door—one just above the smoke generator box portion and one slightly above center of the racked section where food would be. They are performing perfectly. Good construction and a year-long warranty is an added bonus. River Country
When installing your thermometer probe, make sure that it is well-insulated from the casing of the fridge so that you get an accurate reading from the inside rather than the case temperature. I achieved this by lining the hole with cork (from wine corks).
After drilling the holes with a 15 mm circular cutter, I drilled a small hole into the wine corks which would allow me to pass my thermometer probe through. Then, with a sharp knife, I trimmed the cork sides so that they would fit snugly into the hole.
I used two corks per hole that were about 3/4 of their original length, protruding a bit on either side so that the thermometer back was not touching the fridge door.
Step 9: Do a Final Cleaning and Smoke Test
Clean all of your racking and double check the cleanliness of your smoke cabinet. Allow sealant and wet paint to dry at least overnight.
Once all paint and sealant is dry, you can fire up your new smoker and give it a try.
I would strongly recommend reading up on the subject of cold smoking before you try anything. If done incorrectly, it could lead to you culturing some nasty bacteria by mistake.
Take time and care with your hygiene and product sourcing, and make sure your temperatures inside your smoker do not rise too high. If you're careful about these steps, you should be golden.
Good luck, be safe, and have fun.
Tips on How to Make Smoke
So, you now have a completed smoke cabinet and are eager to get some food smoking. There are several ways of making smoke, and the type of smoke that you make will affect the flavour of the item that you are smoking.
It is possible to make your own smoke generator, though it is something that I have not tried so far.
I have personally used the . It's simple and relatively inexpensive and a great smoke generator for those starting out. The maze-like arrangement of the mesh ensures that only a little can burn at any moment, resulting in smoke for a long period of time. A-MAZE-N Pellet Smoker
If you plan on going down the smoke generator route, however, then it is important to take into account the dimensions of your smoke cabinet before you buy, as a fridge with a door that won't close is no good to anyone.
Mix It Up
Feel free to try all different kinds of combinations of wood chips to produce a variety of unique flavours. Who knows what you might discover!
Wood Chips—What to Burn and Why
The choice of wood chips burned in your smoke generator will affect the taste of your food, as each wood has a slightly different aroma and flavour when burned.
Generally speaking, you won't go too far wrong when using wood chips from fruit trees, such as apple, cherry, lemon, fig, apricot, orange and plum.
There are also several non-fruit-tree woods that are widely used and available. These include oak, hickory, maple, ash, mesquite, beech and olive, as well as other more obscure woods such as sassafras, acacia and persimmon.
There are many types of wood out there, and experimenting with different woods and brands will help you achieve a more unique flavour tailored to what you like best.
CharcoalStore is a brand I have used before and makes a number of great wood chips. One of my favorites is the variety that has a mild and slightly nutty flavor and goes well with salmon. I also recommend CharcoalStore's apple wood chips as a great all-arounder, their alder for smoking fish and their olive for a different kind of flavour that works well with poultry, beef and pork. White Oak
(Note: All of the above are intended for smoke generators that use loose chippings rather than custom-formed discs, such as the Bradley Smoke Generator. Make sure that the chips will work with what you have before you buy. The above CharcoalStore wood chips are perfect for maze-type designs such as the one recommended above.)
How to Chip Your Own Wood
You can, of course, chip your own wood if you have a good supply, but there are two things to bear in mind:
- NEVER use wood that has been treated or painted. The additional chemicals will get into your food and make it taste bad. They might also potentially harm you as well.
- For best results when using your own wood, you must season it so that it is very dry. Once chipped, store the chippings in a low-humidity environment. Many commercial chippings are kiln-dried, though I have produced good results with my homemade apple and oak chippings after a year of seasoning (minimum).
Cold Smoking vs. Hot Smoking
What Is Cold Smoking?
Cold smoking is more of a curing process than a cooking process (whereas hot smoking is a cooking process). Smoking has both anti-oxidizing and antimicrobial benefits and adds that smokey flavour we love so well.
Cold smoking normally occurs over a long period of time. For me, 12 hours is the minimum. But some people will gradually smoke some foods for a week or more at temperatures that remain low for the duration of the process.
The normal temperature range for cold smoking tends to be 10–32 degrees Celsius (50–90 degrees Fahrenheit). It is recommended that you never cold smoke at temperatures above this range, as the food may spoil due to the onset of bacterial growth in the warmer temperatures.
There are some products like cheese that can be popped into your smoker with very little preparatory work, but many need to be cured before they should be smoked.
There are a variety of curing methods, including dry curing (great for meats) or brining (soaking in salt water). There is a wealth of knowledge available on curing methods and what to use where. I suggest reading as much as you can before trying that expensive bit of salmon you are longing to get smoking.
I would always recommend using the best-quality meats and fish that you can afford. Similarly, fresh-sourced produce will be safer to smoke and taste a lot better.
If done correctly, and in combination with curing processes, cold smoking can dramatically increase the shelf life of a product, allowing it to keep for many weeks and still taste fantastic. I would recommend starting with inexpensive, easy-to-smoke items such as cheeses until you have your method down and know the ins-and-outs of your smoker.
I hope this has been a helpful or at least interesting read and would love your feedback and tales of fridge-smoker-related activity. Happy smoking.