Kiln dried logs definition: 

1.6M3-kiln-dried-logs-deliveredThis term refers to logs that were cut recently but put in a ‘Kiln’ to decrease the moisture in them quickly. Conventionally, logs have always been dried out over a certain length of time – months or sometimes through the seasons. The negative aspect of naturally drying it out is that it takes much time and is less likely to acquire the moisture level to the lowest thinkable levels. Certain wood like the Oak species can take many seasons to dry out. Kiln dried logs are the finest logs to buy because it guarantees they’re ready for burning. Kiln dried logs are most often referred to as ‘ready to burn logs.’

Read: Interesting document from the Forestry Commission.