I thought that I would share with everyone how I cold smoke salmon with my external smokebox.
My first smoke box was a cardboard box. I cut a flap at the bottom for the door, inserted the hot plate, and used sheet metal fittings on top to attach the tubing. And lots and lots of duct tape. This box lasted manyh years and never caught on fire or deteriorated.
Then a friend saw it and made me one from plywood. I should have never have thrown out the prototype but the wood one works great.
It's basically a box with a single hot plate and ducting that runs to another unit that holds the fish. I used to have it running to a Weber kettle with a hole cut into the side to accept a fitting for the tubing (flexible venting available at most hardware stores like OSH) but the Old Brinkman I now use allows for more sides of fish, if necessary.
I like to use salmon fillets that are 3 1/2-3 3/4 lbs but could only find these two 3 lb. fillets at market. I cut 4"-5" from the tail (approx. 4 ounces) from each fillet and grill them the night before. The tail is sinewy, can get too salty and not necessary to the whole fillet for me.
First I cover the fillets with kosher salt and refrigerate for 6 hours to draw off liquids and flavor the fish.
Then I wash them thorougly under cold filtered water and towel dry.
In order to take the smoke, the fish must be dry and there must be a scab (pellica) on the top side of the fish so I use fans to dry them to get the scab. this takes about 2 hours and I reverse the fillets, and do the underside as well (just for 1/2 hour).
Once the scab is formed, I cover the fish with thin layer of cheese cloth to catch any impurities or ashes from the smoking. I like clean fish.
The smoker is located down my hillside. Getting it there was a challenge but I did not want the smoke to linger near our house.
Pictures include the smoke box. The bucket holds chunks of oak I cut from my fire wood. I only use oak as it is my preferred flavor for lox. It's also what almost every caterer and restaurant serves (oak smoked salmon) in CA.
The smoke temperature cannot get higher than 80°-90° for cold smoking. this will enable the salmon to be thinly sliced as in the final picture. Once the smoke gets hoter, the fish begins to cook--still delicious but will flake apart rather than be suitable for slicing. The hard smoked salmon you find in stores is hot smoked at 160°+.
The tubing (flexible tubing from OSH that is covered with duct tape to prevent tears and extended aboout 7-8 feet).
There's a piece of sheet metal at the end of the tube that inserts into the offset of the New Brunsfel smoker.
The wood tray. It's heavy ss inset from a chafing dish (ex caterer). 3-4 chunks will smolder for about 6 hours.
I use an electric hot plate (1200-1500 watts, can't remember) in the box turned full on.
Notice the slick black (creosote) on the inside of the smoke box. By the time the smoke reaches the fish, it is relatively clean and I have never had any off taste on the fish from creosote.
The wood tray is covered with heavy duty aluminum foil wih holes punched in, and placed on the burner and the door is closed.
I smoke the salmon sides for 6 hours, then refrigerate still covered with the cheesecloth, and slice away the next morning.
I make lox about every two weeks.
Sorry that the pics are so small as I could not find them in my photo library so downloaded them from a post else where. It won't happen again.