+1 what the gentlemen said above.
Most if not all of the bitter taste comes from white billowy smoke. White billowy smoke comes moist/wet wood (including soaked chips) and/or smothering the fire. Keep the
wood (with bark ON if you like) dry, put it on the fire in small amounts so as not to
smother the fire, keep the smoke very thin in that "sweet blue" hue we talk about.
You wont have a problem with bitter....