Safe materials to use in cold smoker construction

[christaylor]

I'm planning on making a cold smoker. As with most of the designs I've seen, I want it to be an off-set smoker: one chamber will contain one of those portable electric hot plates with an old frypan (which contains tea leaves, wood chips or whatever I want to smoke with) and will be connected via a hose to the food chamber. Now, I want--this is cold smoking, after all--the temperature inside this chamber to be as close to the ambient temperature as possible. I have no desire to hot smoke--ever--with this smoker as I already have a hot smoker.

Anyway. The only challenge, as I see it, is finding a suitable material with which to fashion a food chamber. I can't weld (i.e. I don't have the gear, I'd have no idea where to begin if I borrowed some). Ideally I'd like to buy something I can easily modify for my purposes with little more than drill and Dremel. I haven't really considered knocking together a 'box' out of timber but I guess I could be steered in that direction if it was better than the two ideas I'm kicking around at the moment. As I see it, I have two options:

• A metal rubbish bin, which seems to be really popular. There's that whole issue of galvanised steel, tho'. Poking around a few hardware stores locally it seems like if it's a metal bin, you can bet it's galvanised. I've researched the process from removing the coating but the advice is mixed in what it suggests and that's somewhat intimidating. I'd rather not poison myself cleaning out a cheap rubbish bin just so I don't poison myself while smoking in it.
• A polypropylene tub. Now, I know that by plastic standards, pp has a fairly high melting point--between 130 and 160 Celicius. I know that it's food safe. It's used in a lot of sous vide rigs, for instance. The tub, as I see it, has a couple of advantages over the bin. I expect it holds onto heat less readily. Tipping it on its side would allow me to easily access the two or three tiers of shelves I plan to put in there. I suspect I'd even put in the effort to attach the lid to the container with a hinge, allowing me to use it as a proper door.

What I'm unsure about is which is, er, safer. Again, I'm only using it for cold smoking. I understand that the melting point for the galvanised coating is way higher than I'd be exposing it to ... but it's also infamously food unsafe. So long as I keep the food chamber well below the melting point--in either case--am I 'safe'? Even below the melting point, is the chamber going to release some sort of nasty toxins thanks to weathering or exposure to smoke or things released by the food itself (i.e. fat)?

EDIT

For the sake of clarification, I should mention that I obviously don't want to place the heat source in the bin/plastic tub. It will be in something non-flammable such as an upturned terrcotta pot.

 

[smoking b]

How big are you wanting your smoke chamber to be?

 

[christaylor]

I don't have specific dimensions in mind but I'd like to be able to easily fit in, say, a ~2kg slab of pork belly without having to slice it in half. Or two or three kilos of sausages or chicken pieces without having to smoke them in a couple of batches. I mean, I was looking at 55L polypropylene tubs. They seemed like they would be the right size.

However, I figure that if I have a larger chamber then it'll be easier to keep the temperature down.

 

[daveomak]

Chris, morning and welcome to the forum...   For cold smoking, the AMNPS and dust or pellets, from Todd, would be the best smoke generator..  Some members have used a cardboard box for the house with free standing racks for holding the food...  Below is a link to the AMAZING Products

http://www.smokingmeatforums.com/a-maze-n-products

When you get a chance, please stop into "  Roll Call   " and introduce yourself for a proper welcome..... This Forum has great members, enjoy the long smokey ride....    Dave

 

[woodcutter]

What normally happens is once you start smoking you become hooked and want to keep progressing with different foods. The AMNPS like Dave recommended will work in most standard grills gas or charcoal. It is the easiest solution and can be used in a possible future smoker.

 

[captcouillon]

Primary hazards of galvanized coatings are through ingestion or inhalation. Acid exposure can create zinc salts, which are more readily absorbed than metallic zinc. Conclusion: Don't store your tomato juice in a galvanized bucket. Zinc fumes (primarily zinc oxide) can be produced in high heat conditions (in excess of 400C) such as welding, grinding, forging, or casting zinc bearing metals. Conclusion: Exposure to zinc compounds via a galvanized cold smoker, negligible risk. Less than health risks from bacterial hazards from improper curing/handling.

IMHOP Plastic+Heat=Never Good

 

[diggingdogfarm]

Personally, I'd tack together a small smokehouse out of pine, hemlock or the like.
I'd be extremely careful using any metals or plastics that the Chinese have made around food, you have no idea what's in it for sure.



~Martin

 

[dirtsailor2003]

Personally, I'd tack together a small smokehouse out of pine, hemlock or the like.
I'd be extremely careful using any metals or plastics that the Chinese have made around food, you have no idea what's in it for sure.
~Martin

x2!

Cedar would be another good choice. I would avoid any woods containing man-made preservatives, glues, anti-fungal, or insecticides.

 

[christaylor]

Would you line or treat the inside of the smoking chamber with anything or just leave it bare?

 

[alelover]

I made mine out of cardboard and use the AMNPS with no problems and virtually no heat increase inside the box.

IMG_3869.jpg

• alelover
• Dec 16, 2012

 

[diggingdogfarm]

There's nothing wrong with leaving it bare.



~Martin