its moisture content? Moisture content has an enormous effect on heat output.When burning wet wood,most of the heat is used to dry the wood ,to enable it to burn.Freshly cut wood has an average 50-60%,seasoned wood should be 25%,while kiln dried wood should be between 15%and 20%.
 Quality made briquettes such as our very own EziLite fuel briquette,Hotties heat logs,Blazers fuel logs and Hotmax fuel logs are typically below 5% because the raw materials are either dried before production or are from tested naturally dried material to start with,so it will be the same EVERY TIME.You can buy all of these fuels on our Fitch Fuels Section on www.fitchrecycling.co.uk  or call in at our warehouse shop in Stalybridge, Cheshire.