Gavin over at the Simple, Green, Frugal Co-op had a nice post earlier this week about food waste. It got me thinking again about my own habits. Gavin mentioned bones being an issue in his household, and the same is true for me. Bones still are the only food-related waste I create. I'm sending them off to the landfill when absolutely everything else gets either consumed or composted. It seems like I should be able to cross this last hurdle on my way towards zero waste.
In the past I'd done a little research on how to make homemade bone meal. First, I would need to dry the bones, then find a way to pulverize them before spreading them on the garden. That first part, drying them, was a problem for me. I couldn't justify wasting energy by drying them in the oven, yet I couldn't leave them out in the sun to dry either, for fear of attracting vermin. That's as far as I got before I gave up--it shows just how rigorous my thought processes can be sometimes. ;-)
So this time around I think I've finally figured it out. Sometimes I just make the simplest things way too complicated. Yesterday I took all the bones out of the freezer (that's where I store them, since I only go to the landfill about twice a year). I've been boiling the bones for almost 24 hours now. This seems like a much better approach than drying them, because I also will get a huge pot of bone broth. Since I didn't think this through ahead of time, the broth won't be fit for human consumption. Some of the carcasses I threw in the freezer had sat as leftovers in the fridge for a little too long and seemed a bit "off". So, this batch of broth will not get eaten, but in the future I'll be careful to segregate any questionable pieces when I put them in the freezer. Then the good stuff can be made into an edible, mineral-rich broth. Most of the carcasses already had been made into stock once, but I've been in the habit of only simmering them for a few hours--not long enough to release the minerals in the bones.
Once the bones are soft enough, I plan to dilute the broth and spread it over the garden (for this batch). The bones I'll crush and bury in the compost pile. I took out some of the bones awhile ago to see if they had softened. Some of the smallest ones just crumbled between my fingers. The larger bones will need to simmer longer. I've read if you have a meat grinder, you should be able to send them right through. I don't have one, so for the larger pieces I'll opt to just mash them to bits with a hammer.
How did I deal with the issue of using too much energy to do all of this? Easy. I have baseboard electric heat in my house. I turned off all the heaters and for the past day have been heating the house with just the heat from the simmering bones. It's been relatively warm this week, so that little bit of heat is just enough to keep the house comfortable. In the future, I'll need to plan to do this only during the heating season. Twice a year would probably be often enough, since I don't go through much meat--so early in the heating season (say, the end of October) and then again late in the heating season (sometime in April). That way the heat from cooking can also serve as needed heat for the house.