Adventures with Almonds, Part I: The Marvelously Fragrant Hall’s Hardy Almond

This is the first part of a two-part series. I’ll publish the second, on making marzipan, shortly.

In the meantime, you might check out two articles I recently published with Mother Earth News, Finally, a Good Thermometer for Home Preserving” and Fun to Watch, Fun to Eat: Pickled Mixed Vegetables Brined in Glass.”


Hall’s Hardy almond tree

I finally got around to cracking last fall’s crop of Hall’s Hardy almonds, my biggest in the five years since I planted the tree. I had more than half a cup of nutmeats!

Hall’s Hardy is actually a peach-almond cross. But because it blooms late, resists fungal disease, and self-pollinates, it is considered the only almond variety suitable for growing in the Pacific Northwest. Or so it was considered until recently, when Jim Gilbert of One Green World introduced several Ukrainian almond varieties, all of which are said to have the same virtues as Hall’s Hardy, plus more: They are true almonds, with soft or semisoft shells. But the Ukrainian varieties are yet unproven in Oregon. For now, I’m grateful for my tiny almond harvest, especially because these almonds have something the soft-shelled true almonds almost certainly lack: the lovely flavor of almond extract—that is, the flavor of bitter almond.

Hall's Hardy in shellCracking a Hall’s Hardy almond is problematic. Once freed of its husk, the nut looks like a peach pit, and it’s just as thick and hard. I tried using a kind of nutcracker, meant for walnuts and pecans, that surrounds the whole nut; as you press the two arms together, the hinged central cup hugs and squeezes the nut inside until the nut breaks at the seam. I cracked two or three nuts with this cracker, and the small kernels, to my delight, turned out whole. And then the hinge sprang.

hammering almonds, bestSo I got out a hammer, an old bread board, and a dishtowel I’d consigned to the rag bin. With the hammer method it’s important not to use a board or a towel that you care about, because you’re bound to damage both. You place a few nuts at a time on the board, lay the towel over, and then bang, bang away. You remove the towel and collect all the nut pieces, most of them itsy-bitsy. And then you toss out a mountain of thick shell pieces and sweep the stray ones from underfoot before they damage your floor or your flesh.

By this point some of you dear readers no doubt feel alarm, and not about the dangers of stepping on nut shells. It’s my mention of the flavor of bitter almond, right? The essential oil of bitter almond is nearly pure benzaldehyde, a chemical that signifies the presence of amygdalin, which enzymes in the intestines convert to prussic acid, also known as hydrogen cyanide. And cyanide kills. Some scientists say that eating 50 bitter almonds will kill an adult; a child may die after eating only 5 to 10. Other stone-fruit kernels—apricots, peaches, and plums—contain the same flavor, the same chemicals, and the same deadly power.

Despite its toxicity, amygdalin has a long history as a medicine. In China, for example, apricot pits have been traditionally used for coughs and constipation. But amounts taken were probably miniscule before the 1950s, when amygdalin in the form of laetrile, or so-called vitamin B17, became a folk treatment for cancer. In the United States, the popularity of laetrile surged after 1972, when a researcher at Memorial Sloan-Kettering Cancer Center reported that the drug inhibited secondary tumors in mice. Although other researchers were unable to confirm these results, desperate cancer patients traveled to Mexico to buy laetrile or got their amygdalin directly from stone-fruit pits—especially from apricots, whose kernels, even richer than bitter almonds in amygdalin, are used as a food flavoring in Turkey, Tunisia, and elsewhere in the Mediterranean region. At least a few children who might have survived cancer succumbed to laetrile poisoning instead.

Because some people will apparently force down the bitterest pill or nut if they think it’s good for them, bitter almonds cannot legally be sold in the United States. You can buy “pure” almond extract, which may be made from apricot or peach pits, or almond paste, probably flavored with apricot pits if not a synthetic imitation, but you can’t sell the almonds.

Some businesses do sell them, however, and those businesses include Trader Joe’s and Costco. Or so say consumers of Marcona almonds from Spain. Apparently, a bitter almond or two appear now and then in a bag of roasted Marconas, a variety with rounded kernels that are especially rich in oil. One bite of a bitter Marcona leads to spitting and gagging and a foul taste in the mouth that lasts the whole day through. Or so say these startled consumers.

This never happens with California almonds. You might occasionally taste a rancid California almond, if your nuts have been stored for too long. A rancid nut may make you spit and gag, but rancidity is not the same as bitterness.

The problem with Spanish almonds is something biologists call xenia, after a Greek word for hospitality. Xenia happens when the pollen of a plant of one genetic strain affects the seeds and fruit of the fertilized plant. This effect is distinct from the effect the pollen has on the next generation. Xenia is the reason gardeners plant their sweet corn far away from any field corn, popcorn, or ornamental corn, even if they don’t plan to save seed for planting in a subsequent year. The pollen of any of these other types of corn could turn the sweet corn starchy. In the same way, ears of white corn pollinated by yellow corn will turn out yellow, and the kernels of popcorn pollinated by sweet corn will turn out sweet and, probably, shriveled.

In the United States, all our commercial almonds are grown in California, in Central Valley orchards so extensive that beekeepers from all over the country truck in their hives for winter forage (this annual gathering of the hives is largely responsible for the rapid spread of various bee pests and diseases across the continent). Blooming California almond orchards are a lovely sight to see, as you race up or down the interstate, but they are a picture of modern, industrial farming. No doubt Spain, the world’s second largest almond producer, has orchards much like them, but I haven’t seen them. Traveling through Andalusia one winter, I got a different view of almonds in flower. Masses of pale-pink blooms were scattered here and there over the landscape. The almond trees, some small and some towering, marked old fence lines, roads that might have been buried in sand, and other past and present boundaries where the trees had grown up from seedlings and thrived without care. Almonds have been growing here since Roman times. Although bitterness in their nuts is a recessive trait, controlled by a single gene, bitter almond trees dominate in numbers because critters avoid eating their nuts—that is, their seeds—and also, apparently, because sweet almond trees are less tolerant of very dry, sandy soil.

In Spain, sweet almond orchards are mostly planted in damper, coastal areas. But sweet almonds can also grow on irrigated land or on dry land without irrigation if the scions are grafted to bitter almond trees or to peach-almond hybrids. It is in these dryland orchards, I suspect, that xenia happens. The sweet almond flowers are supposed to be fertilized by the pollen of other sweet almond varieties that bloom at the same time and are interplanted in the same orchard. (Self-pollinated varieties are yet a novelty in both Spain and California.) Every once in a while, however, a bee carries pollen from an almond tree growing wild in the fencerow or anywhere else in the vicinity; honeybees, after all, often fly two miles from the hive in search of pollen or nectar. Xenia happens when a bee brings pollen from a wild, bitter almond tree to a sweet almond tree with a recessive allele, that is, an allele—or gene variant—that when matched with another recessive allele will cause bitterness. Marcona almonds, like most of the other varieties grown in both Spain and California, is heterozygous for sweetness. From the flower where the bee deposits pollen, a bitter nut develops.

The more bitter the nut, the more amygdalin it contains. A study of Spanish almonds found amygdalin ranging from 2.16 to 157.44 milligrams per kilogram in nonbitter almonds, 523.50 to 1,772.75 milligrams per kilogram in semibitter almonds, and 33,006.60 to 5,3998.30 milligrams per kilograms in bitter almonds. The least bitter bitter almonds, then, had 210 times as much amygdalin as the most bitter nonbitter almonds. The most bitter bitter almonds had 25,000 times as much amygdalin as the least bitter nonbitter almonds.

Given that my Hall’s Hardy almonds weren’t almonds at all but an interspecies cross, I didn’t know whether to classify them as nonbitter, semibitter, or bitter. (I will continue to call my almonds almonds, however, because genetists have determined that through millennia of development peaches and almonds have crossed repeatedly.) Because of their strong aroma of benzaldehyde, I figured that the Hall’s Hardies must contain more than a little amygdalin. I found an old gardening publication from Cornell University that recommended against growing either Hall’s Hardy almonds or another hybrid variety, called Ridenhower, because of the nuts’ bitterness and possible toxicity. But I could taste barely any bitterness over the strong benzaldehyde flavor of my nuts, and I tend to be extra-sensitive to bitterness. They tasted so good, in fact—so much more interesting than California almonds!—that I would have tossed all the kernels into my mouth if I hadn’t had other plans for them.

My plan: I would make my own, no-flavor-added marzipan.

23 thoughts on “Adventures with Almonds, Part I: The Marvelously Fragrant Hall’s Hardy Almond”

  1. That’s a very interesting explanation of the reason for some sweet almonds being bitter, thanks Linda.
    Something you might like to try if you have any left to crack, is to stand the nut upright on a hard surface (oak, locust, aussie hardwood, concrete, iron) and smack it as hard as you dare on the point with a hammer. With practice and confidence a single hit will split the shell while bouncing the hammer back into the air giving whole kernels. It helps to have a small hollow in the anvil to stop it skittering out sideways and holding the nut with long-nose pliers or some sort of tongs to keep fingers out of the way will help with confidence. I haven’t yet got around to making a wooden almond anvil and confess to holding with my fingers using the concrete floor of the garage, so far without incident but it tends to take a few blows.
    I have Fabrin to crack which have very thick shells but I do have trouble with the semi-papershell varieties.

    1. We crack our Hall’s hardy Almond with a hammer on a brick with a towel. Nice almond flavor, with little bitterness. We would like to learn a process on cooking the almonds, whether steamed, boiled or roasted does not matter. We just want to make a usable paste for using?. Making snacks

  2. So you grow almonds in Australia? And they are sometimes bitter? Do almonds grow wild in the area?
    Thanks for the tip about standing the nut upright. I did start to try that, but then I chickened out. I didn’t think to use an anvil with a hollow or long-nose pliers or tongs. I hope you’ll try these things yourself. You don’t want a permanently deformed thumbnail like my father’s from his years as a carpenter.

    1. Well here in NZ there are people playing around with small scale commercial orchards but mostly I think we are just enthusiasts seeing what will work. My trees are still very shy producers, I think that is partly because they flower when there are very few bees and then of course there are the late frosts that thin the early fruits but apricots are more sensitive. I don’t think there are wild almonds yet (no squirrels etc to spread the nuts) but there have been stuff-ups by nurserymen selling industrial (bitter) almonds as sweet by accident.
      Australia does have large orchards but beyond that I don’t know if they have bitter almonds in the mix.
      Your Hall’s Hardy look like they have thick flesh, our sheep consider almond husks a delicacy even when they’ve dried out.
      Incidentally my partner sometimes makes marzipan to a Norwegian method, no water just egg white and icing sugar but sadly we haven’t yet had enough to use our own almonds. It’s all done in the food processor and is ready when it forms a giant lump, sorry I don’t know the proportions but the egg white goes in last so probably adjusted to get the right consistency.

  3. I’d forgotten that you were in New Zealand.
    I thought the Hall’s Hardy husks might turn out to be not-very-good peaches, but I didn’t find them edible at all. I’m glad your sheep are less picky.
    Egg white is sometimes added to marzipan, I think, to help hold the paste together. I didn’t try adding egg white because some of my readers would no doubt worry about using raw egg. Besides, there is no egg white in the recipes in my favorite source of information about marzipan, Martha Washington’s Booke of Cookery and Booke of Sweetmeats, edited by Karen Hess. But traditional marzipan methods do tend to differ by country.
    Does icing sugar in New Zealand contain cornstarch, like confectioner’s (or powdered) sugar in the United States?

  4. I live in NY. I initially planted 4 almond trees. My Hall’s Hardy tree is now about 20′ high x 20’wide after only about five years, and I sometimes need to cut it back. It has been through an unprecedented hailstorm and the bitterest of cold weather. Yet it always produces an abundant crop of nuts.It’s not called “Hardy” for nothing.

    The pro side: We have a problem in suburbia with squirrels. The one nut that squirrels can’t crack is a Hall’s Hardy Almond! I’m at war with the squirrels as they often get the crop of the softer shelled Ukrainian varieties I planted.

    The con side: Humans also find harvesting these difficult. Realize that I need to harvest many hundreds of nuts from that tree and relieve them their of sticky, gooey husks. When done, getting this goo off your hands is tough going – it is tougher than most glues. Use waterless hand cleaner. Then comes the cracking. I use a bench vise. Typically half the nuts when cracked are either dried out or were ruined by moisture. It is one hell of a lot of work to produce a pound or two of nuts. But the ones that remain are delicious. I must be ‘nuts’ to keep doing this… LOL

      1. This year (2018) my almond trees produced virtually nothing. Despite the trees being mature, healthy, and that they always produced abundantly in past years, this year they produced few nuts and nothing that was edible. This was due to eight heat waves we had from June through September. And yes, I counted them. The unusual, recurring heat affected other vegetables I planted as well. We can’t fight nature, and no one can control the weather. Better luck next year…

    1. Cracking Hall’s hardy almonds or black walnuts or any hard shelled nut, you need a Grandpa’s Goody Getter nut cracker. You get whole nuts meats. It is an investment but will last generations, and will be appreciated by whoever inherits your Almond trees.

  5. Thank you so much for this post. I bought a property a few years ago (Sonoma, CA), clearly the tree in question is an almond tree, but was baffled why my de-husked almonds’ looked so much like peach pits (and not the yellowish looking softer shell I am used to). I literally cannot crack them with a nutcracker!! (but boy, when I do, they totally taste like almond extract and are amazing). I also got a big haul this year (maybe because of all the 2016-7 rains) and I guess I’ll be going to the hammer as well. But, I am at least so grateful for someone to help me understand why these look so different and are so hard. Hall’s Hardy, I will go read up some more on that.

  6. After we take off the soft outer coating, we put the almonds in the clothes washer with a tiney bit of dish soap on the longest cycle and they come out clean and fairly dry. Then I rput them in the food dryer overnight to make sure they are dry.
    Better cracking methods would be appreciated.

  7. This is our first year getting almonds from our Hall hardy almond tree. I told my husband I think we got a peach tree instead 😂 because the outer flesh smells like peaches. Are they supposed to dry on the tree? It’s late September here in Michigan and they have fallen to the ground. I cut off the fleshy fruit part with a paring knife. Let some of them dry on the windowsill. Haven’t attempted cracking any yet. Sounds like we better use a hammer 😂

    1. Jean, the flesh is peach-like but not palatable. If I remember right, the flesh dries on the tree and is easily peeled away. I wonder how my Hall’s Hardy almond tree is doing on the farm! I miss it.

  8. My grandson sent me a video of a person cracking a black hard shelled nut with a hammer. He is in Puerto Rico… his first time there. He showed the nut and said it is an almond. Didn’t look like any almond I’d ever seen, so I began my search online and discovered this information. Thank you so much. I feel much better now. I didn’t want him to be poisoned by eating something strange.

    1. Willie, I’m wondering if your grandson was eating the nuts of Terminalia catappa, which is called almendra because of its appearance but is not a true almond. Here’s the Wikipedia article on Terminalia catappa. Your grandson may discover all kinds of strange and wonderful foods in Puerto Rico!

    1. Sandi, I never made almond milk from ‘Hall’s Hardy’, but I don’t know any reason that you couldn’t. I imagine that the milk would be especially flavorful.

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