Coffee Logs
The Wood House Research Farm reuses coffee grounds from the , Arlington, Virginia's first green
restarurant and winner of many similar accolades. The coffee logs are made in several ways:
Outdoor logs: Coffee grounds and occasional discarded filters are mixed with a small amount of cleaned waste
vegtable oil (post-transestherification) and enough wax to give it shape.
Glycerine is a by-product of biodiesel
transestherification, and it's improtant to remove it.
The combination of coffee nitrogen and glycerine gels is
not nearly as volatile as nitro-glycerin (the production
of nitro-glycerin is how biodiesel
was discovered in the
mid-1900's), but burning glycerin creates acrolein, which
is known to be carcinogenic and
produces the putrid
smell of burnt grease. It is also a respiratory irratant.
Indoor logs: For the safest indoor logs, we mix the coffee grounds with only wax. Paraffin wax works well, but it is
a product of fossil fuels, so a vegetable-based wax or beeswax is preferable and cleaner if the price allows.
Firestarter logs: Coffee grounds plus a little wax and methanol-free glycerine gives off a lot of heat that will lead
to combustion of insufficiently dried wood. We still recommend not using glycerin in a combined space.