Black Walnuts

Harvesting your own black walnuts is a labor of love gaining popularity with more and more foragers. This post will show you everything I've learned: harvesting, cleaning, storing, cracking, cooking, and everything in between.

Like a lot of other people, I have memories of tripping and stepping on ugly, gooey black walnuts in the yard when I was growing up. They were a serious pain when I had to mow the lawn, and I thought they were weird, not food--no way they could actually be related to regular nuts that we eat, right?

As I worked my way through the culinary industry, black walnuts took on a new identity as a treasured, expensive product that was near impossible to source. When I was opening up my first restaurant, I looked at buying them from an exclusive purveyor and did a double take when I saw the price tag: over 40$ a lb.

Black Walnut vs English Walnut

Both walnuts are related and are in the Juglandaceae family. Black walnut trees are Juglans nigra and are common wild walnuts. and English walnut trees are Juglans regia-the same walnuts sold in grocery stores.

The trees are slightly similar and both have opposite, pinnate leaves but the nuts are very different. The pictures below illustrate some differences between both trees.

English walnuts have very thin shells compared to black walnuts, and the flavor is very mild, where black walnuts have incredibly hard shells and a very strong, earthy flavor. If you like the flavor of both nuts they can be interchangeable in cooking.

Where to Buy Black Walnuts

Hammons is now the premier supplier of black walnuts in the United States, who sell them at industrial scale at an affordable price. When I need large amounts I order from them. They're also the only supplier that sells black walnut oil.

Hammons nuts, while available in bulk, are mechanically separated, and they take a beating during the process in flavor and shape. Simply put: cracking black walnuts by hand is how you get the most intense flavored, perfect-looking nuts possible.

Why would you harvest your own black walnuts with large scale purveyors in business, you ask? One word: quality.

You'll be able to smell the bowl of nuts as you crack them, and pressing them between your fingers will yield a fresh, aromatic oil. You'll be able to see black walnuts as a luxury, and brag to your friends about your command of a lost art.

Harvesting Black Walnuts

There's plenty of methods and opinions out there, but after a couple years of harvesting, here's what I've found to be the easiest for me. Once the trees start to drop their nuts around early October, I wait a bit for the hulls to soften before I gather them.

What happens here is that fly larvae will get into the thick green hulls, and begin feeding on them. After a bit, the hulls soften a little. From here, I go outside with a plastic tub, and, wearing gloves and using boots, I rub my heel over each nut, and the once hard green hull simply melts away.

Some nuts may need to be stomped a bit, and that's fine. What's happening here, is that I'm allowing the fly larvae (walnut maggots) to digest the hull, soften it, and in the process do a lot of the work of hulling them for me.

If you harvest the walnuts green, with the hulls firm, you'll need to find a way to remove the hull yourself, and you can find plenty of ideas for how to do that online. My advice, is make your peace with creepy crawlies, and let them help remove the green hulls for you.

Nuts can also vary drastically in size from tree to tree, so you'll also want to look around and find trees you like the best.

Processing Black Walnuts  

After removing the hull the nuts will still be covered in black goop and need to be washed. Fill a big Rubbermaid or plastic container with them, get the hose, and fill the tub with water.

Using a stick or some other crude tool, swish the nuts around in the water to help loosen clinging bits of hull. Dump the water, then repeat the process a few times until the water runs clear.

Discard any nuts that float, and do not leave the nuts in water for longer than it takes to wash them, or they can mold during the curing process.

Drying / Curing

Once the nuts are drained they need to be cured/dried. Put the nuts in a wide container to dry in a cool place with ventilation--a porch or garage is fine but make sure squirrels can't get into them.

A net bag works, as will laying the nuts out on screens, or in a cardboard box as long as you have a fan or something to move air over them, as even a small amount of water in the bottom of a container can cause the nuts to mold.

The most important thing is that your nuts are bone dry. There's a few ways to dry the nuts I'll go over below.

Box Fan Method

I like to use sheet trays and a fan in my garage, as illustrated below. It typically takes 2-3 weeks for my nuts to dry completely.

Dehydrator

You can also dry black walnuts in batches in a dehydrator, (use a large square model like Harvest Maid or Excaliber) and it is the fastest way to dry them.

Putting them on cookie sheets in an oven with an adjustable temp around 150 could work too, but I would crack the door to avoid cooking them. Use this as a last resort.

Allow the cleaned nuts to dry and cure for roughly 3 weeks or until they're completely dry. From here, the nuts are shelf stable, and can last for a few years, allowing you to crack and enjoy them as you like. 

Outsmarting the squirrels 

It can be tempting to store the nuts outside after washing, especially if you don't have room to put the nuts on screens, but squirrels are talented nut thieves, and, if you leave the nuts out unattended for even a few days they will find your stash and help themselves.

I learned the hard way when I picked and processed all the black walnuts I could find one year, left them in a box outside, only to find that over the course of a week, the single squirrel that runs around our yard had helped himself to over 2 gallons of nuts.

Cracking 

The most difficult part, and why I swore I would never crack my own black walnuts. One taste of a freshly cracked black walnut though and you'll be a believer.

Black walnut shells are amazingly hard--much harder than English walnuts, and you won't be cracking these in a rocking chair with Grandpa for Christmas, rather, you and grandpa need to go to the garage and make a little nut cracking set up. Here's what you'll need.

Workbench or other firm surface

Cracking surface. I use a molacajete here, and I highly recommend it, since it's also the greatest spice grinder you'll ever meet.

Since they're made from basalt/volcanic rock, they're heavy and hard, and no amount of nut cracking or missed hammer blows will harm them. You can also use a vice.

The secret to getting whole ¼'s: a metal snips

Snips are indispensable and without them, even with a great hammer technique, you will never get the picture perfect nuts you see in my images. The snips are used to spot-treat problem shell parts, releasing the perfect quarters. See my video for a hands-on demo.

Nut pick, preferably homemade

Conventional nut picks are obtuse, useless tools for black walnuts and other nuts like butternuts and shagbark hickory. They're just too thick, and all they're going to do is crush your precious nutmeats.

The good part is, it's easy to make a homemade nutpick. Take a dowel, preferably made from birch so it won't split, and cut it into lengths a couple inches long. Pound a nail about halfway into the dowel. Next, pound the head of the nail flat using a hammer--this will be your "pick". Sam Thayer showed me his process of making these, and they're light years beyond conventional nutpicks.

How to crack by hand

Take each nut, and, holding them by the points or seams, give a good crack to the flat portion of the nut just until you hear it crack--don't smash them. Now rotate the nut and give them another crack on the seam (top or bottom).

With enough practice you should now have a cracked nut, with 4 whole quarters. Put the nuts in a bowl and continue until you have a large bowl of cracked nuts, then go though each of them, using the snips as needed to free the whole quarters.

After cracking, rinse and dry the nuts to remove any tiny shell particles that can crack teeth.

There's a few products on the market that make things easier, but one of them stands above the rest. The Grandpa's Goody Getter is by far the easiest, most efficient black walnut cracker I've ever used. It's an investment, but it's worth it.  

Cooking 

To me, black walnuts are really the Rolls Royce of nuts, and there's nothing like a freshly cracked black walnut with it's unique scent and curious aroma. The flavor is incredibly strong, and keeps throughout cooking in whatever you make, bread and baked goods like cookies and cakes, or just sprinkled over granola or yogurt.

Since you just went through a lot of work to get all those perfect halves, I think it's good to leave them in large pieces, generally. One of the purest ways to enjoy black walnuts is to simply sprinkle them on things. Ice cream is pretty epic too.

More Recipes with Black Walnuts

Additional Information

Do fresh nuts need to be toasted?

Once the nuts are shelled, the perfume and aroma is at its peak and there's no need to toast the nuts, contrary to what I drilled into my line cooks for years.

But, as nuts sit in on a shelf the flavor diminishes and, after a month or two, a gentle toasting will revive them a bit. I always toast nuts that've been stored or frozen.

Rancid nuts

Black walnuts are widely known for their tendency to go rancid stored at room temperature. How do you know if the nuts are rancid? If you eat it and it tastes terrible, like mold, it's rancid.

Always store black walnuts in the fridge after cracking. For long-term storage, vacuum seal them and freeze.

Yellow streaking

Once I started cracking black walnuts from trees in Wisconsin, I noticed that some had yellow streaks. Terrified of the nuts being rancid, I threw plenty of them out. That was a mistake. Referring back to rancid nuts, if your black walnuts are rancid, you will definitely know.

As far as I can tell, the yellow streaking is a harmless anomaly (Sam Thayer said it might be related to temperature) but, if you know the science behind yellow streaking in black walnuts, let me know. Rest assured, I've eaten plenty of nuts with yellow streaks, and they're just as delicious as other black walnuts. 

Uses for cracked nut shells and scrap 

After you've cracked some black walnuts, you'll have plenty of shelled nuts, and probably a few with small pieces of nut meat left inside. I save all my nut cracking scrap in a box in the garage, then I make piles of the spent nuts on a rock in the backyard.

Every morning I get to witness the birds and squirrels who come to feast on the nuts left in the shells—it's a great way to share your harvest!

Squirrel bait 

We know squirrels love to steal black walnuts. If you like to eat squirrel occasionally as I do, know that spent black walnut hulls and shells make some of the best squirrel bait you can find. Put some spent nut shells in a trap and watch them come. 

Green, unripe walnuts

Black walnuts, and other walnuts, give us a lot more than just nuts and oil. The green, meristematic nuts have long been used for making edible products and things from condiments to preserves and liquors.

Green walnuts are outside the scope of this post, but I do harvest plenty of them, typically in June in Minnesota and Wisconsin. You want them about the size of a ping-pong ball, or sometimes smaller, depending on the recipe you're preparing.

If a knife or pin can't be stuck through the young black walnut, it's too old, but can still be used to make nocino. Unripe black walnut leaves are also harvested to make different things, most notably black walnut bay sauce, a sort of vinegar infusion.

Butternuts: the white walnut or juglans cinerea

Butternuts are similar to black walnuts, but also very different, so different that I'll write about them in a separate post. For our purposes here, know that if you find some butternut trees, you're lucky, since they suffer from butternut canker, and they're numbers are dwindling.

In Minnesota, they're listed as an endangered species. The flavor of the nuts is nothing like black walnuts. Butternuts are fresh, buttery, and without any sort of tannins like English walnuts. They're delicious, but more difficult to find than black walnuts.