The current batch of bacon has been in the smoker again today however this time I used my data logger to compare the temperature in the smoking chamber with the outside temperature. I was using my large barrel smoker with an AMNPS type smoke generator.
Smoke generator lit and in firebox. Hickory pellets.
Internal temperature logger probe clipped just behind the bacon.The external probe was clipped to the leg of the smoker.
Notice that for most of the day the internal temperature was tracking 2 C (3.6 F) above the outside temperature however at 17:00 I moved the internal probe and clipped it to one of the wire hangers at the top of the bacon as I put 8 Kg of cheese in the other side of the smoker. The temperature difference then increased and it started to track the outside temperature 5 C (9 F) higher.
Firstly this shows that even in a fairly large smoker the heat produced by the smoke generator is significant. Secondly it shows that even within the 10" or so height difference within the smoking grill and the top of the meat there is a measurable temperature gradient.
To verify this gradient I will place both probes in the smoker tomorrow when the bacon goes back in for its last day.
OK so what? ...
... At the temperatures today this was more of just an interesting exercise, however when smoking on warmer summers days this gradient is likely to be amplified and could have a real impact depending on where the food is placed in the smoker. When smoking something like butter that 5 degrees could be the difference between lifting it out and mopping it out and for cheese the difference between it sweating in the smoker or not. For cold smoking salmon over an extended period it could also impact food safety.
Its OK you can all go back to sleep now