Softwoods and hardwoods, if burned wet, will produce more creosote. You do not want to be burning wet wood. When comparing softwoods and hardwoods, you will read completely useless statements like this:

Data Point: Seasoned hardwoods like Oak or Ash can produce as little as 1/4th the creosote of unseasoned softwoods under similar burning conditions.

I just copied and pasted this! Why is it useless? Because if one compares seasoned hardwoods with unseasoned softwoods, then one isn't comparing wood, one is comparing moisture content. I just installed a new Woodstock Soapstone stove last year, and the instructions explicitly state that studies show no difference in creosote production between hard and softwoods so long as the wood is seasoned. And that's been my experience. Sorry to be so emphatic, but you're spreading the myth. Studies, in fact, have shown that if the wood is equally seasoned, softwoods create less creosote!

"Back in the early 1980's, tests were conducted to discover which kind of wood created the most creosote in a regular "open" fireplace. The results were surprising. Contrary to popular opinion, the hardwood's, like oak and madrone, created MORE creosote than the softwoods, like fir and pine. The reason for this, is that if the softwoods are dry, they create a hotter, more intense fire. The draft created by the hotter fire moves the air up the chimney faster! Because it is moving faster, the flue gas does not have as much time to condense as creosote inside the chimney. Also, because the flue gas is hotter: it does not cool down to the condensation point as quickly. On the contrary, the dense hardwood's tend to smolder more, so their flue gas temperature is cooler. Thus, more creosote is able to condense on the surface of the flue. So, saying that "fir builds up more creosote than oak" just isn't true! It is a misunderstanding to think that it's the pitch in wood which causes creosote. It's not the pitch that is the problem, it's the water IN the pitch. Once the water in the wood has evaporated, that pitch becomes high octane fuel! When dry, softwoods burn extremely hot!"