I have a 22.5 WSM and smoked two pork butts and they have a bitter smoke taste. I used kingsford charcoal and used the method of putting a chimney of hot coals in the middle of the charcoal. I used apple wood and just put a piece on top of the hot coals and made sure it was burning before putting the meat on. I have used the WSM since Dec with good results but the last couple times my chicken and ribs and now my butts have a bitter smoke taste. I open the bottom and top vents up all the way till it gets to 230-250 and then adjust the bottom vents down to under half way and leave the top open all the way. I am looking for some feed back please.Thank you.