Introduction: Miss Betsy's Cold Smoke Generator

Picture of Miss Betsy's Cold Smoke Generator

Fall is already here, the days are cool and unlikely to push the thermometer over 70F, which means perfect weather to make bacon!
Last time I made bacon I used a pretty complicated arrangement of a stove and stove pipes to cool the smoke and guide it into my smoke chamber; this time I made myself a small and easy to maintain "Cold Smoke Generator".

Materials needed:
16/14 oz. can
36 oz. coffee can
#6 metal screws
8" piece of 3/8" iron pipe
Several brass and copper fittings and pipe (get your idea from the pictures)
1/4" O.D. plastic hose
Some kind of feet (I used 3 shelf brackets) Make sure the apparatus doesn't tip over and set your house on fire!
An old aquarium air pump. (Even a new one isn't too expensive ~ $20).
Wood pellets or Hardwood! saw dust to fire the thing up.

Tools you should have and which will make completion of this project a lot easier -_^

Drill / Drill-stand
Assorted drills
Hack- Jigsaw
Metal file

Step 1: Main Parts

Picture of Main Parts

I decided to use a 16oz. can as burner chamber and a coffee can as reservoir for the wood pellets. Should be available in every household.

Step 2: Attaching the Burner

Picture of Attaching the Burner

Put the smaller can centered in the middle of the bottom of the coffee can and mark with a pen. I divided the circle in 8 pie shaped pieces and drilled a hole in the middle of this circle. With the help of a jigsaw I cut along the lines so that I could connect these 2 cans. Bend the sheet metal up, set the smaller can on top and use metal screws to secure it.

Step 3: Preparing the Venturi Tube

Picture of Preparing the Venturi Tube

In my parts drawer I found this 8" piece of 3/8" galvanized iron pipe. With the help of a drill and a file I made a slit roughly in the middle. The plastic hose, coming from the aquarium air pump, was attached with some connectors and brass fittings. You will have to play around a bit depending on what you find.

Step 4: Preparing the Burner

Picture of Preparing the Burner

In order to make the burner work, you will have to drill 3 holes; 2 to push the venturi pipe through, and 1 to ignite the hardwood pellets and provide oxygen for the embers. I used a 9/16" drill which is about the right size for the 3/8" pipe to fit through snug.

Step 5: Assembling the Cold Smoke Generator

Picture of Assembling the Cold Smoke Generator

I had 3 shelf brackets at hand to use as feet which works great but I am sure there are plenty other ways to stabilize the smoke generator. Just make sure you don't set your house or garage on fire!
In the pictures you see a prototype where I used a drain strainer as bottom for the burner. I found out that this didn't work so well so I made the version with the 3 holes in the burner. This latest version works at least 2 hours  without maintenance which is sufficient.

Step 6: Trial Run

Picture of Trial Run
The cold smoker doesn't need much wood pellets to run and produce sufficient smoke. What you see is plenty for at least 8 hours of operation which will soon produce some fantastic bacon. (I will tell you about that in a separate instructable!)
Watch a short video of the smoker in action:


MonicaP12 (author)2015-08-18

OK, I am new to smoking and really only need to smoke some ricotta since I cannot buy ricotta affumicata (smoked ricotta) in the USA. My question is, where do you place the item you are smoking? Inside the large can? I really would like to make this because I live in an apartment and it looks small enough for what I need to use it for. Also, can someone make a suggestion for an alternate pipe since the galvanized pipe can give off toxic fumes?

MissBetsy (author)MonicaP122015-08-19

I'm afraid I have to disappoint you :( What you see here is just a "Smoke-generator". For smoking cheese or meat you need a "Smoke-chamber" as you can see here: - unfortunately I doubt that you will fit that in your apartment. You might find the right thing by looking around here on Instructables. A word of caution though, smoke might contain toxic particles!

vocalpatriot (author)MissBetsy2017-12-09

any cheap grill with lid would serve well for a smoke chamber...heck even a zip-lock bag would work to cold smoke cheese and such.

MichaelW157 (author)MonicaP122017-03-07

Black iron, or gas pipe, available at most hardware's and,.. I got it at LOWES....It comes in precut sizes....

Dominic Bender (author)2012-10-30

I have been considering smoking things for a while now, but never got very far. Your generator looks simple enough, although I have yet to come across a coffee can that size.

Gallon paint can , ask at store for an empty one, not used..???

vocalpatriot (author)MichaelW1572017-12-09

lowe's and the home despot both sell new, empty quart and gallon sized paint cans and lids.

MissBetsy (author)Dominic Bender2012-10-30

As I found out, it is not really necessary to use such a big can as a reservoir, as the smoker doesn't use very much pellets / sawdust. In need, I am sure, a neighbor or colleague at work could help out with a coffee can.
In any case, good luck!

GregS3 (author)MissBetsy2014-09-04

We just bought a house and inherited several dozen gallon sized paint cans. Properly cleaned, one of those should work as well as a coffee can

mikeofa2 (author)2017-11-14

Can anyone explain to me why galvanized pipe in the can and copper pipe exiting? Couldn’t I just use all copper or All galvanized? And the comment regarding the Venturi effect, does that mean the copper isn’t soldered and can be moved in and out of the galvanized pipe?

cutshopguy (author)2013-02-15

Hi Miss B,
love your work. Just a question about how you fire up your wood, whether its hardwood pellets or wood chips or whatever, to produce the smoke? How do you get it to the smoke point and how do you maintain the temperature so as to continue producing smoke?

MichaelW157 (author)cutshopguy2017-03-07

You could put a soldering iron in the side hole till the pellets start, clean thoroughly, or buy a cheap ( Harbor Freight ) one , as lead on the iron is no good,.. but for just starting and not leaving it in should be OK...

MissBetsy (author)cutshopguy2013-02-19

In front of the can is the firehole as described in the instructable. The hardwood pellets are ignited there with help of an blow torch. The aquarium pump is used to create a Venturi effect in the tube inside which means it sucks air (oxygen) in and keeps the ambers ambering and blow out the smoke on the other side in direction of the smoke chamber. Everything clear now?

texaskathyy (author)MissBetsy2015-02-27

How are the ashes removed?

MissBetsy (author)texaskathyy2015-03-01

Ashes fall through the bottom holes, can be cleaned out through the fire-hole or are removed when the fire goes out and the smoker is emptied and readied for a new run.

Nemesis201077 (author)2013-01-31

Looks like a good system to me. I've been looking at making a cold smoker for quite some time. I have a couple of old Dishwashers and a refrigerator, which might make a useful smokebox. As yet I hadn't designed a smoke generator, though I may try to make an electric heater to burn the wood chips. The airpump is a new thing, I might even be able to re-use the refrigerator compressor for this.

MissBetsy (author)Nemesis2010772013-02-01

I was thinking myself of using a refrigerator as smokebox. That way I could even in summer keep the contents safely cool. A dishwasher might work just as well.
To your idea with the electric heater: I tried this last time I made Speck. I had the heater right in the smokebox which made the contents way to hot and then the whole thing started to burn which wasn't so good either. So be careful if you go this way!

MichaelW157 (author)MissBetsy2017-03-07

What about an old range it already has racks inside , is insulated to a degree, & would be good for cold smoking as it isn't as large a capacity.?

Ttalos (author)2013-02-07

I think this is a fantastic idea and plan on building one myself. I just though I would throw out a caution about using the galvanized pipe. Since the pipe will get hot it will give off some Zn fumes. This can be toxic if too much is inhaled or added to your food. If you can use another metal I would suggest it. If not you can remove the Zn and use the pipe safely.

MichaelW157 (author)Ttalos2017-03-07

black iron pipe would be a better choice and is cheaper it's natural gas pipe. I find it at Lowes, and it's in precut sizes...

The Gurgling Cod (author)2016-05-21

Is there a brand of smoker pellets you prefer? Thanks, and looking forward to trying this.

nocode54 (author)2016-02-12

Excellent concept, design, and Instructable. This design looks to be exactly what I am looking for to add cold smoke capability to my 1940's vintage Kelvinator/smoker. I am about to try a build. I am unsure about your images where the air tube connects to the larger pipe. Is the smaller tube slid within the larger pipe and extended past the opening to create the venture and draw smoke? Which direction is the opening in the larger pipe oriented? I'm sure not upward but toward the air inlet? Away? straight downward? Thanks

MissBetsy (author)nocode542016-02-14

Yes, the smaller tube is slid in the larger pipe slightly past the opening to produce a draft that keeps the ambers smoking. It's kinda trial and error to see how it works best. The opening of the larger pipe point downward to prevent ashes etc. from blocking the tube.

nocode54 (author)MissBetsy2016-02-28

I am having trouble with sustaining a smolder in the pellets. I am
using a 1200 cc/min air pump and I suspect that volume is insufficient.
I have twice the ventilation you show and, unless I remove the lid, the
burn/smolder will not be sustained. It goes out in a few minutes. Any thoughts/suggestions would be appreciated.

nocode54 (author)MissBetsy2016-02-15

Thanks so much for the prompt reply. I understand so much better now. I am anxious to try this but don't like to be out tinkering with the smoker when the temperature is 0-F.

BillD17 (author)2015-08-12

john.nicolas.henderson (author)2015-01-27

Do you need to add a grill Inside the coffee can to put you meet on it?

kerry.mckenzie.39 (author)2014-10-10

Would a baby formula tin/can be big enough?

astral_mage (author)2013-09-29

also bewary of the wood pellets cuase many of them use toxic binders.

streetrod5 (author)2013-02-09

Very well constructed smoker - it looks professional. I was thinking about making Alton Brown's bacon smoker, but although easier, it takes up more room. Plus, this one looks cool.

MissBetsy (author)streetrod52013-02-10

I looked up "Alton Brown's Smoker" and that is a hot smoker whereas my smoker is a cold smoker, two completely different philosophies!

streetrod5 (author)MissBetsy2013-02-14

MissBetsy, you are so right; I had misread AB's instructions. What I really wanted was a COLD smoker. So, really, you've saved my bacon!

swalker3 (author)2013-02-11

Hi Betsy thanks for a great instructable. I have a question though, approximately how far inside the larger tube of the venturi tube does the small tube need to go? I'm guessing just past the slit from the way you have arranged the parts in the second picture?

MissBetsy (author)swalker32013-02-11

Yes that is about right. It's a try-and-error- thing and you will see at which position it will produce the most smoke when you do a trial run. Mark this position then because you might have to take the element apart for cleaning purposes.

t.rohner (author)2013-01-24

I think this generator is very nice, but a bit complicated.

I wanted to build a smoke generator, that doesn't generate much heat.
The other advantage was a very economic wood dust usage.
I was looking for building material, but didn't get lucky.
So i ordered this one.
I have no affiliations with them, but it smokes for 10 hours with just a little bit of wood dust.
If you can build it for a reasonable price, do it.

MissBetsy (author)t.rohner2013-01-25

That looks very simple and I am sure one can regulate the amount of smoke easily. Probably less attention involved than with my version of a cold smoker. But as I mentioned somewhere, what I really would like is a wood stove and an attic in an old farmhouse to produce bacon.....

t.rohner (author)MissBetsy2013-01-26

You would like something like that ;-)

Ricardo Furioso (author)2013-01-24

Miss Betsy,
Thank you so much, this is inspiring. And I love your bacon instructable.
Two questions.
Where are you located?
Can you please make a Speck instructable?
My grandfather taught me to love it on fresh bread.
He was from Cortina in SudTirol.
Much appreciation.

Thank you and your grandfather from Cortina had access to probably the best Speck in the world. The big difference between my method and the speck you know is the choice of meat. Traditionally Südtirolean and Italian Speck are made from the hindquarter of the pork and the relation of lean meat to fat is higher. I might try this next time.
For 12 years now, I reside close to the Niagara Falls, NY

Courageous story.
He was born in Cortina in Sudtirol.
His people fought against the Italians in the Great War.
When he returned to Cortina, it was flying an Italian flag.
He could not bear it. Instead of becoming an Italian citizen he became an American citizen.
I would love to know how to make any Speck.

About This Instructable




Bio: You might call me "Jane of all trades, mistress of none"; "all" is definitely an exaggeration but I am interested in lots of "trades" and ... More »
More by MissBetsy:Miss Betsy's Excellent BaconMiss Betsy's Cold Smoke GeneratorMiss Betsy's Rechargable Solar Nightlight II
Add instructable to: