When we take nourishment from the consumption of animals, we like to get the most out of each creature that we possibly can; this is done both out of thrift and out of respect for the life taken to sustain our own.
What this often means in practice is that we will roast a whole chicken and eat the meat and skin, then boil the carcass for broth and pick the last scraps of meat from the bones for soup. From a fatty animal (like a side of pig) we will render the fat and use the lard for cooking. Or from a hairy animal we will enjoy the meat and bones and try our hand at tanning!
But we still end up with parts that we are not prepared to make use of directly: boiled bones and scraps of cartilage, entrails and defatted skin. What to do with these?
There are several options! Many municipalities in the Vancouver area now accept these sorts of scraps in their green waste collection programs. Not so in lovely rural Sooke. A typical in-the-kitchen vermicomposting setup can only accommodate a very small amount of meat scraps, and certainly not the entire collection of one deer’s viscera. A digester composter is a great solution, except for areas with hungry bears wandering through – your digester bin may not survive the pillaging and this sets up a bad situation for the bears.
So what to do? Compost like the pros!
A windrow is a row of organic matter deposited by machine harvest, raked by hand, or… blown together by the wind! Windrow composting makes use of the piling up of organic materials to harbour an inner core that is safe and stable for the necessary micro-organisms to thrive and do their work.
Windrow compost piles can be intensively managed to produce top-quality soil, with constant temperature and humidity monitoring, regular turning, active aeration, and measured carbon:nitrogen ratios. Or you can opt for decent results and lot less effort by setting up a passively aerated static windrow pile.
To allow aeration into the windrow (to promote the aerobic bacteria, not the stinky anaerobic ones) we started by laying down a bed of branches.
On the bed of branches we spread out two hay bales that had gotten wet and were starting to moulder.
The branches will allow air to be drawn into the windrow as it releases CO2. The layer of hay will keep warmth in the core and not have the composting material simply fall down and plug up the airways the branches provide.
A few more branches and then we add our treasure of deer guts and the meat scraps we had been collecting in the freezer (not wanting to send them to landfill).
And then we pile on the hay – another 6 bales! It is important to make the mass large enough that the inner core can be quite warm and the outer lay will insulate. There also needs to be a lot of carbon material (brown organic matter like hay/straw/leaves/wood chips) in comparison to the nitrogen material. A low C:N ratio would be 50:1, I’ve seen much higher ratios recommended on the ‘net depending on materials used. At 50:1, even the 8 bales used here might not be enough for the amount of meat scraps we put in. We’re going to see how the pile settles after a week or two, then likely add on some more straw. And some lumber tarps will be added to keep the rain off (too much moisture reduces core temperature and leads to anaerobic conditions).
Here’s how it looked when we called it “done for now”. It is about 4 feet tall at the peak.
The neat thing that makes this ‘pile’ a ‘row’ is that as we generate more scraps we add them to one side of the pile and cover with more branches and straw. We keep building this sideways into a row and the composting core that we’ve established here will grow sideways too as more material is provided. Eventually we will be able to dig in to our starting point of the windrow and pull out excellent fertile soil!