How To: Cleaning Black Walnuts
Monday, November 07, 2011
My wedding anniversary came to pass a few weeks ago, and my husband, as usual, gave me a gift. No, not jewelry or flowers—a box of foraged black walnuts.
True, it’s an odd gift, but certainly not one I’ll ever turn away. My husband collected the walnuts from a tree near where he works, and they’ve been resting on our back porch ever since. What have I been waiting for? Well, the outer hulls need to soften up. You’ll know it’s time get rid of the hull when you can easily dent it with your thumbnail. Any harder, and you won’t be able to cut into the hull with any degree of success.
If you’ve never attempted to de-hull black walnuts, be forewarned: it can get messy. The flesh inside the husk can permanently dye everything in its path dark brown, so pick up a pair of protective gloves—latex is good. Some people recommend gloves that are rated to withstand solvents. It’s not a terrible idea, but not entirely necessary…as long as the gloves are strong.
Okay, so you’ve got your gloves. You also need a sharp knife, a bucket of water, a trash bag, and a bunch of newspapers over which to work. Slice into the hull with your knife, but don’t press in too hard. It’s not that you’re going to damage the walnut shell—but the shell is so hard, it’ll dull your knife. Drag your blade around the hull of the walnut until you’ve got a solid slice around the equator. Another word of warning: you may see maggots (husk fly maggots, to be exact). They’re gross, but it doesn’t mean the inner nut is bad.
Twist the two hull halves apart, drop the hull in the trash, and the nut in the water. Repeat until you’re all finished up. And yes, it’s best to toss the hulls in the trash instead of adding them to your compost heap because there are compounds in black walnut hulls that are toxic to plants. Granted, if you hunt on the internet hard enough, there are ways to use the hulls—making ink, herbal hair dye, etc.
When you’ve got a bucket full of walnuts, stir the water with a stick. I don’t just mean a leisurely stir, either—agitate the crap out of the water and nuts because you’re trying to encourage the remaining bits of hull to fall off. Drain the water (remember: walnut hulls are toxic to plants, so don’t pour the water directly onto your prized peonies—it can also kill off earthworms) and fill up the bucket with clean water. You may need to repeat the process up to four times to get clean walnut shells.
At this point, spread the walnuts out in a box or on a screen and allow them to air dry for a few hours in the sun. Having an overcast day? No worries—put the walnuts on a cookie sheet and place them in an unlit gas oven for 24 to 48 hours for drying. If you don’t have a gas oven, you can try drying them in your oven after you’ve baked something: the oven needs to be at around 100 degrees.
But you’re not done yet! Gather the dried walnuts into a mesh bag and hang on your back patio or some other ventilated indoor area for a period of 4 to 6 weeks. This is technically described as the curing period. Don’t attempt to shell them until you can shake a nut and hear the meat rattle within.
So you wait it out, and your walnuts are finally ready—this is where the hard part begins. Ever tried to crack a black walnut? It’s really tough—the process and the shell. I’ve heard of people running over black walnuts with a car to help crack the shells. I personally have attempted to de-shell them by banging the crap out of a walnut shell with a hammer. Probably the easiest way to crack black walnuts, though, is with a vise: place the nut end-to-end in the vise. Place a container under the nut. Crank the vise until the nut just cracks. Some people recommend soaking the nuts in water again for an hour or two before you undertake cracking—it allegedly cuts down on the amount of flying shell debris. When you’re finished with the cracking, turn your attention to the bowl of nuts. It’s unlikely you’ll get many whole pieces of walnut freed from the shell during this process. Yes, you can use a pick to pry the meat out, but if you would rather have whole meats you’ll need some kind of cutter to remove more of the shell. I’ve read that some people use wire cutters.
Use the nuts within the next few months—there is quite a bit of oil in the nuts, so they can go bad. If you wish to store them long term, you’ll need to freeze the nutmeats.
Yeah, it’s a lot of work. Why would anyone bother? Well, a few reasons, really. First and foremost, black walnuts taste better than regular walnuts. But also, they’re really nutritious—chock full omega-3 fatty acids, which are good for our brains.
Aside from eating them out of hand, there are some really interesting things you can do with black walnuts. I love this recipe for acorn squash lasagna with black walnut cream—you can make it almost entirely out of locally grown ingredients. Other options: banana-black walnut cake with caramel frosting, black walnut ice cream, black walnut shortbread cookies, black walnut pumpkin pie and pumpkin bread, black walnut brittle, pork tenderloin with black walnut mole sauce, pickled walnuts, shiitake and black walnut tartare, and black walnut stuffing with figs and bacon.