I will give it a shot, though I wouldn't describe the OFF flavor as bitter, but I am also going to do something that I read elsewhere and that is to clean out the cold smoker chimney by placing it on my BBQ at high heat to burn off the buildup.
For others who come across this issue, here is the comment from the
Amazon page:
Q:
I am getting way too much smoke (bitter creosote). Cheese and salmon inedible. Main smoker was unplugged with vent 1/3 open. What am I doing wrong?
A:
Give it plenty of oxygen at first to allow the temperature to rise high enough for what's called pyrolysis and gasification. Don't be too concerned about flame up, that's required to get the thin blue smoke that you're looking for. With this cold smoker I fill it to the top of the chute with dry chips and turn it on with the lid open and the cap off of the chip chute (close the smoker door and chimney vent for this step). You'll begin to see very heavy smoke rising out the top of the wood chute as the wood heats up (don't worry, you don't want that creosote and char inside the smoker or on the food) after a minute or so, the smoke will begin to thin out and the chips will begin to flame up some, from the bottom near the burner, let it flame for a few seconds just until it gets good and warm (I know this will freak some people out but you need the heat initially). Use tongs or a bbq glove and cap the chute then close the lid, the flame will go out quickly and you'll have the hot fire box needed for the "thin blue" without the heavy smoke. Open your chimney vent and begin smoking.
Don't soak the chips for this application because wet wood makes bad smoke. We're often told to soak the chips to make them last longer (and it will) but it produces a heavy white/yellow smoke; because it causes the wood to smolder rather than burning. Smoldering is caused by combustion temperatures that are too low and by lack of oxygen. It gives the food a dirty ash tray flavor rather than the good smokey taste you want.
I've had very good results using this method with the Masterbuilt cold smoker kit. For hot or cold smoking. I know this is an old thread but I hope it will help someone looking for a solution to the heavy smoke. Good luck & God bless