I have been going through the usual shenanigans that comes with changing the sawdust. I had been using fine oak shavings. I am now using fluffy red pine. The latter burns like the clappers and this has implications... The trick is to sacrifice a few pots to the learning process and only sacrifice them one at a time under the same weather conditions. On the first burning, you might let the air in, and then see what happens. On the second burning, you might shut the air down, and see what happens. Comparing these two pots will show you what you need to know, more or less. A third pot should allow you to fine tune what you have learned. You see, its not really the wood or sawdust that matters as much as how you burn it. You have to find the "sweet spot", and the trick is to listen to the fire. If its roaring, the fire is too hungry for oxygen and it will steal it from your pots. Your pots will be dark. If the fire is too slow, the pots will also be dark.... or white.... If you hear the fire happily murmuring to itself, you have probably got it about right. Yes, you need to listen to your smoke fire. It will tell you what you need to know.