I started looking around for a good cheap way to do some cold smoking. The general consensus was that the soldering iron/tin can method was the best way to go. I'm not sure who first used that method, but there are a bunch of different tutorials. Here is one: http://food52.com/blog/4189-your-best-kitchen-hack...
I didn't really like this though. One of the big warnings for that method was watching out for BPA lined cans. My problem with this is that the only way to tell if a can is BPA free is to track down the certain brands that use BPA free cans. I really didn't feel like having to deal with that. Secondly, I was concerned about the plastic handle of the soldering iron melting/burning. My first halfhearted attempt was throwing a soldering iron in a coffee mug with some wood chips. Long story short, I ended up with some hickory/plastic smoked cheese. Finally, I felt as though I could do better than the $10 - $15 some of the tutorials were claiming. My method comes out to about $6. $4 for the heating element and $2 for wood chips, assuming the aluminum foil, cord, shrink wrap, and grill are available
Step 1: Get Your Stuff Together
List of things you will need
Soldering Iron Heating Element: https://www.sparkfun.com/products/9509
Cord from something old or broken. I used the cord from the soldering iron I mentioned earlier. A cord from an old alarm clock, VCR, or pretty much anything will work.
A little bit of shrink wrap or electrical tape
Then you will also need aluminum foil, wood chips, and a grill or some sort of vessel to put everything in.
Step 2: Cut the Device Off the Cord You Want
Remove the device from the cord you are planning to use. Try to cut it closer to the device, so you will have a longer cord.
After you have the cord, split the two wires, strip them, and slide some shrink wrap over them.
Step 3: Attach the Heating Element
Connect the two wires you stripped in the last step to the two wires on the heating element. It doesn't matter how you pair the wires.
Next slide the shrink wrap over the exposed metal on your connections and apply heat to the shrink wrap. I used my girlfriend's blow dryer to get the shrink wrap to shrink and conform to my connections.
You could also use electrical tape instead of the shrink wrap.
Step 4: Get Your Smoke Packet Ready
Using aluminum foil make a little basket and place a handful of wood chips in it. Right here I'm using mesquite chips.
Place your heating element on top of the wood chips.
Close the aluminum foil packet with the wood chips and the end of the heating element inside. Keep all of the aluminum foil on the heating element side of the mounting plate.
Flip the packet over, and poke some holes in it using a fork.
Step 5: Smoke Some Cheese
Once you have the packet ready, place it in your grill with whatever you are trying to smoke.
Close the lid, plug in the cord, and you are ready to go. Based on my experience, the amount of wood I used should keep the grill nice and smoky for about an hour.
So far I have smoked some cheese, butter, olive oil, and an apple. Everything has turned out very well and the apple was much better than I expected.
If you have any questions, comments, or suggestions please let me know.