Wood Pellets - Hardwood or Softwood?

Left to Right: Hardwood Pellets and Softwood Pellets

Many people believe hardwoods are superior, since hardwood logs do burn better than softwood logs. This is not necessarily the case when raw material is processed to form wood pellets. Hardwood logs are much drier than softwood logs and the low moisture content results in a hotter, cleaner burn. But, in the process of manufacturing pellets - whether softwood or hardwood - the moisture content of the wood is reduced to a narrow range of approximately 4%.

Once the moisture has been removed, the two remaining components of the pellet are cellulose (wood fiber) and resin (sap, 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. Therefore, softwood pellets burn hotter than hardwood pellets, and give a bit higher heating value (BTU's) per pound.

Heating values are difficult to differentiate across almost all pellets; as a result, what consumers tend to care most about is ash content. The main factors that impact ash content are the cleanliness of the raw material (tree bark and other impurities) and the quality of the manufacturing process.

Posted: November 11, 2013
By Dean Fischer