“I went to the woods because… I wanted to live deep and suck out all the marrow of life…”
Recently, we were given the bones of a large, healthy cow, and I knew it was time to enact a dream that I have had for a while now – rendered bone marrow. Bone marrow is pretty much mineral rich fat, traditionally wherever cultures depended on larger mammals for food, they prized bone marrow as an essential source of nourishment. Marrow can be consumed as bone broths, the bones broken open and simmered gently for a long period, it can be eaten raw – straight out of the bone, and if you have enough of it, it can be rendered for storage just like any other animal fat. Traditionally, pemmican consisted of dried, pulverized meat stuck together by rendered marrow fat.
For the uninitiated, what I mean by ‘rendering’, is heating tissue fat until the oil liquifies and separates from the proteins. The best example of this process is bacon – when you cook bacon, the bacon grease left over is rendered fat, it was seperated from the protien (bacon) through heating.
Most of the marrow lies inside the ‘marrow bones’ – long shaft like bones of that make up the front and hind legs (femur, ulna, all those shafts..). Ribs, shoulder blades and the spine do not (usually) have extractable chunks of marrow in them. For rendering, we smashed the marrow bones open, and took all the greasy chunks out…
At this point, the raw marrow is absolutely amazing! Apparently it contains stem cells, crazy nourishing growth hormones, no doubt eating it raw is the most amazing. We wanted to render it at the lowest heat possible, so we chose the ‘wet’ rendering process, putting all the marrow in a pot, covering it with water, bringing it to a low simmer for quite a while (it was on the woodstove, maybe 3 hrs very low heat?), then letting it cool overnight.
The oil seperates from the water, rises to the top and solidifies. It is then skimmed off, and gently heated in another pot just enough to liquefy and evaporate some of the excess moisture that might be kicking around. Pour the liquid oil into a jar, and, if you want my advice, store it uncovered, in a cool place. We store all of our rendered fats uncovered, and have noticed they do not go rancid or mold half as quickly as rendered fat that can’t breathe. If you have a fridge or a freezer, putting a lid on it likely won’t do any harm, but if it is at all warm, we just tie a cloth around the mouth of the jar and leave it at that. If creatures scavenging your food (mice, rats..) is an issue, then you will have to figure something else out. After skimming off the fat, we rendered what was left in the pot again, for just as long or longer, and after cooling go just as much fat as the first skimming.
The rendered marrow is amazing! Buttery yellow, rich, one of the best fats I have ever tasted (in my top 3).