We are frequently asked if hardwood pellets are superior to softwood pellets. Most people’s perception is that hardwoods are superior; after all, hardwood logs do burn better than softwood logs. However, this is not necessarily the case when raw material is processed to form wood pellets.
Hardwood logs are significantly drier than softwood logs and the low moisture content results in a hotter, cleaner burn. However, in the process of manufacturing pellets – whether softwood or hardwood – the moisture content of the wood is brought down into a narrow range of about 4%.
Once the moisture has been removed, the two remaining components of any pellet are cellulose (the wood fiber itself) and resin (or the sap in the wood, which is essentially a natural oil). Cellulose has the same heating value, whether originating in softwood or hardwood form. Resin has a higher heating value than cellulose and the resin content of softwoods is higher than that of hardwoods. As a result, softwood pellets burn hotter than hardwood pellets, yielding a slightly higher heating value (BTU’s per pound).
Heating values are close across almost all pellets; as a result, what really matters most to consumers is ash content. The main factors that impact ash content are the cleanliness of the raw material (that is the absence of bark and other impurities) and the quality of the manufacturing process.