F3, A Canola of Worms
Part II: Go Nuts
In Part One, I recommended that the F3 project switch from canola and soy to animal fats, both for frying and for fuel. Another option is to switch to black walnut oil. Black walnut oil is not suitable for frying, but frying is not very healthy for people or the planet anyway. Black walnut oil is very rare, very pricey, and very prized for lower heat applications, mainly baking. The oil is not ideal for biodiesel either, but black walnut shells may be usable for fuel.
Black walnuts are about 60% fat. This aromatic oil must be stored carefully because, like flax oil, it is 94% unsaturated (mostly omega-6). This makes black walnut oil inappropriate for high heat applications. However, the flavor of black walnuts, said to be five times stronger than that of the English walnut, is very desirable for other culinary uses like baking. Hammons Products Company, the largest black walnut producer in the country (family owned for over 60 years), has a lot of recipes on their FB page.
Native only to Eastern North America, black walnuts are somewhat expensive (though less than macadamia nuts and even pecans) because the average yield (by weight of meats from unshelled nuts) is only 8%. Fortunately, the unshelled nuts are cheap to come by. The first option is to plant trees, and The Biltmore could surely plant enough to eventually ensure their own supply. According to PFAF, black walnut trees are fast-growing, with yields at least 2.5 tonnes (MT) per hectare, and most trees produce well every other year. The rest produce steadily each year or at least every three years. Black walnut also yields one of the most expensive and sought after American woods. You can make ketchup from the green fruit, and even tap the tree for syrup at a sap to syrup ratio of 67:1 (for comparison, maple syrup is 40:1 and birch is 80:1).
But what black walnut is most well known for is ice cream. This is what 40% of the black walnut harvest currently goes into. Brands include Baskin-Robbins, Blue Bell, Edy’s, Mayfield, and many others. Some companies report that it is their third best-selling flavor, and sales are increasing (source).
One of the noblest and grandest trees in any American forest is the American black walnut, and while a little slow at the beginning of its career, it is only a question of time when it will overtake all others. It knows no disease or pests, and he who plants it lays a foundation for 20 to 50 generations to come as well as for himself and those of his own household.
J.C. Cooper, Walnut Growing in Oregon, 1910
Wild black walnut trees start to fruit at about 5 years and can live to about 250, but they don’t reach large fruitings for about 20 years (wiki; much more detailed cultivation information here). Fortunately, there are already hundreds of mature black walnut trees in Asheville proper alone, where homeowners complain about the mess they make each year. So much the better for those of us who value them. Here’s my veteran apprentice a block from my house. She’s not sure she wants to share!
Are there enough black walnut trees in Asheville to supply the project? That depends, of course, on F3’s goals. Hammons goes through, on average, at least 25 million pounds a year of unshelled black walnuts. These are collected at 250 stations spread across about 15 states. That’s 100,000 pounds per station. With each tree yielding about 100 pounds per season, that’s 1,000 trees. Asheville proper is a little over 40 square miles. That’s one tree for every 25 acres. I couldn’t find figures but surely we have at least this many. That comes out to 8,000 pounds of nut meats a year, which Hammons sells for $12 a pound (more for smaller quantities).
Practically all Hammon’s black walnuts come from wild trees. These trees grow themselves. They don’t need to be watered, fertilized, or sprayed with pesticides. They are “beyond organic.” This is possible because, in the past century, despite the huge value of black walnut wood, some people were thinking further ahead than a year’s profits, including the creator of corn flakes:
Unfortunately, the black walnut now has at least one serious disease. Thousand Canker Disease (TCD), which has the potential to drastically reduce the population of black walnut trees in our region, was previously known only in western states but has recently been found in Virginia and eastern Tennessee. Infected trees take 8-10 years to show symptoms and then 1-3 years to die. The nuts do not spread the disease and there is confidence that it can be contained, so that “at this point in time there is no need for walnut producers in the eastern US to alter any production practices or marketing plans” (source).
If so, the best part is that the project wouldn’t have to go and collect the nuts: people would gather them and bring them to you. Nearly every one of the millions of nuts that Hammons uses is gathered by hand by private individuals. These individuals (or families) bring them in the hull (or husk; see photo below) to over 250 buying locations, where the nuts are hulled by a machine and people are paid for unshelled nuts usually less than ten cents a pound, i.e., $80 to $120 a pickup load of unhulled nuts.
Last week, Hammons announced that this has been the worst year’s harvest since 1990. They blamed it on a drought, not TCD, but offered 13 cents a pound, the highest price they have ever paid, and still “only” got 6.5 million pounds. In the next 2-3 years, however, they expect a bumper crop of 30 million pounds (38 million pounds in 2008 was only its third largest crop ever). If the project gets cracking, so to speak, maybe it can catch the bonanza when it happens.
So how do supply costs for the oil measure up? First you have to add in hulling and freight. Hulling runs about three cents a pound. At ten cents a pound, the total cost with hulling and freight runs about 17 cents. But freight would not be relevant if the only hulling station is right at the processing plant. In that case, your total cost would be about 13 cents.
Now, math is not my forté, but at 8% yield, that’s $1.63 a pound for the meats. At 60% fat, that’s $2.71 a pound for the oil. At a typical fat density of .91 g/cc, a pound of oil is about 17 fluid ounces, which comes out to 16 cents an ounce. I found three companies including igourmet selling black walnut oil at $1.25 an ounce and one at $1.625 an ounce. Only Hammons sells it cheaper — for 88 cents an ounce.
So that’s, on average, about 800% markup. Of course you have to figure in the cost of shelling (assuming you have to shell the nuts first to be pressed for oil, and I’m not sure you do), pressing, and packaging the oil. But it sounds like there plenty of room for that.
Would people in Asheville be willing to bring their nuts to a collection station for ten cents a pound? If that’s $80-$120 a pickup load, that’s almost twice what you’d get for firewood (a pickup holds about half a cord, which currently goes for $60-75). Or take aluminum cans: in WA at least, you can get 45 cents a pound for them. Wild black walnuts weigh about 12 grams. Aluminum cans are 13.6 grams. It takes about thirty of either one to make a pound.
How long does it take to cut and split half a cord of wood, or to collect a pound of aluminum cans (assuming you have plenty of supply)? I don’t know. But as far as black walnuts go, one author reports that one can pick 6 to 8 bushels an hour beneath relatively abundant trees. Is that accurate? This October, an apprentice and I gathered only about three bushels of nuts from a tree on Lakeshore in a couple hours:
That’s only 3/4 bushel an hour, but that’s because we spent 90% of that time husking the nuts on the spot. Hence her lovely henna’d hands:
Subtracting husking time, it took .2 hours to collect 3 bushels, or 15 bushels an hour, or 7.5 bushels a person. This matches the author’s estimate.
The author goes on to say that ten cents a pound for husked nuts comes out to 88 cents a bushel for unhusked nuts. How did he come up with that? This ag paper gives a hulled to hulled weight ratio of .4-.6 to 1 (this one says .4:1). At 7.5 bushels a person-hour and 50% yield, it means you’re gathering about 3.75 bushels of husked nuts an hour. Hulled black walnuts are about 40 pounds per bushel, so that’s 150 pounds of hulled nuts an hour, which actually comes out to $15/hr. The author doesn’t show his work, but he concludes that a person can make only $7 per hour (not counting delivery/sale time). That matches this article which claims only 62.5 pounds an hour, which at ten cents a pound is only $6.25/hr.
Would people in Asheville gather and deliver black walnuts for $7/hr? If the 30M# that Hammons buys on average each year come in one pickup truckload (1000# given price figures above) per person, then 30,000 people, mostly in the midwest, do find this to be worthwhile. It seems to me that in this economy, unemployed or not, plenty of people would be willing — or willing to employ their kids — to do this. But if necessary, there seems to be plenty of margin to pay a lot more per pound.
This could be a huge good publicity campaign for Advantage West and The Biltmore, and I’d be happy to be a spokesperson for it (though I probably wouldn’t say, “sell us your nuts“). I’m already starting a similar initiative this spring, The Afikomen Project, which trains children to gather mushrooms to sell to The Asheville Wild Foods Market. This will be the first wild foods market in North America and will likely start out as part of The Asheville City Market. People can bring their nuts there or, during the week, to the same place we’ll be buying wild produce for resale (TBD). Details on how black walnut buying stations actually work can be found here.
As far as collection mechanization goes, there is a machine resembling the kind used to pick up golf balls that is said to make the job much easier. This simple one sells for about $52. This bigger, rolling design starts at $375. The only way I can see one of those being cost-effective would be for a lawn maintenance company to buy a more commercial model such as the Savage harvester and pay people for the walnuts. F3 could consider collecting the nuts itself this way or offering that option.
Here are some commercial walnut expeller presses for sale. Normally, I’m sure you would have to shell the nuts first. Here’s how Hammons does it. And on the left is how the Buncombe Fruit and Nut Club did it for their big festival this past October.
The social benefits of nut cracking parties aside, for the purpose of oil extraction, I wonder if the whole nut can simply be pulverized and fed through the machine. If so, I wonder if the pressings could be used in poultry feed since birds eat gravel on purpose for their digestion. Otherwise, it can surely be fed to insects or microorganisms or used for fuel…
Here is a powerpoint on “Using Walnut Shells For Power Generation” and analysis data listed here. Finally, here’s a video of a homemade walnut shell gasifier. Be sure to see the mobile version! I can see it now: a nut collection mobile running on walnut shells. The pun potential is enormous.
These are my recommendations for F3, which would of course require a new name, but for me, that’s the easy/fun part! Here’s to a vibrant local, nature-based economy in WNC.