If you add the wood chips too soon it will cause creosote to form on the meat. You need to let everything heat up for about an hour before adding chips.
Preheating your MES which I strongly advocated especially for the older MES models with lower wattage elements, and has some benefit even for newer higher wattage units too, especially when ambient temps are low. Preheating - the lower the ambient the longer preheat, allows all the metal inside and even the insulation between the walls to come to temp, this will help with the MES achieving set point temp faster and faster recovery when you open the hatch. Newer MES units with higher wattage elements in normal ambient 50º+ even a 30 minute preheat is beneficial, however many wait until the last minute. One suggestion is when you pull your racks & pans to foil the pans and spray the racks with Pam turn on you MES, set the temp to 270º and it will preheat while you are prepping, when your water is boiling, load the drain pan, then water pan add boiling water, and either add racks loaded with meat or add meat later. Thus you have preheated and your chip pan should be hot enough to burn chips effectively.
The posts above are accurate when they advise to put a lot fewer wood chips in than what the manual says. Personally I like to start with 8-10 chips for the first 15 minutes then add another 8-10 chips, after another 15 minutes 10-12 chips, after you should have a nice bed of hot ash and can now go with 14-20 chips. Mileage may very depending on your model of MES, you should now have smoke for 20-30 minutes before you add chips. Chips soaked wet or chips dry won't matter you will have smoke in 3 minutes or less wet or dry. My preference is wet, my opinion the chips smolder longer and produce more smoke wet. The big thing is to watch the smoke "thin blue smoke" is what your after, if the smoke is dark then you need to reduce the amount of wood chips. You know when you have good "thin blue smoke" besides seeing it you can smell it, it smells sweet, ( I use mainly hickory, oak, almond, apple, other wood might have a different smell when TBS is achieved).
