I had an interesting call this morning. A woman wanted to know whether Hall’s Hardy variety of almonds had to be processed to remove the cyanide to make them safe for eating. I knew apple, cherry, peach and nectarine seeds (all in the same family as almonds) have cyanide in them, but never gave any thought to whether almonds did. Rarely would we eat enough seeds of apples or peaches to get a toxic amount of cyanide. However, we often eat almonds in quantity without getting sick.

Could almonds be poisonous? I asked our Cooperative Extension nutrition and food safety specialist about this. She called the American Almond Board for information. Turns out there are sweet almonds and bitter almonds. The person at the Almond Board looked up Hall’s Hardy variety and couldn’t find it in any of their lists of sweet almonds. He suspects it must be a bitter almond rather than a sweet almond. Sweet domesticated almonds are grown commercially and due to a genetic variation from their bitter cousins, they do not contain the toxic chemical glycoside amygdalin, the precursor to hydrogen cyanide (prussic acid) that occurs in the bitter almond. Sweet almonds require very little processing to eat; although since 2007, there is a law in the U.S. that commercial almonds grown in the U.S., including those labeled “raw”, must be pasteurized to eliminate the risk of salmonella.

In bitter or wild almonds, the chemical compound becomes toxic hydrogen cyanide when the almond is crushed, chewed or injured with mechanical handling. Approximately 100-200 milligrams of cyanide when eaten can kill an average-sized person within minutes. Each raw bitter almond can produce 4 to 9 milligrams of hydrogen cyanide (Shragg et al, 1982. Western Journal of Medicine). Just a few handfuls of bitter almonds can kill a person; lesser amounts can cause serious health problems such as kidney failure.

Even with the danger, some people still grow bitter almonds for the almond extract oil used in sweets or cooking. Reducing the hydrogen cyanide requires crushing the seeds, drying the crushed seed powder into a cake, soaking it in water to break it up and then distilling the product. Yet, just 7.5 milliliters of bitter almond oil has resulted in death.

When I was unable to find anything definite on Hall’s Hardy, the caller checked with the nursery where she purchased the plant and was told it is an edible variety.

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11 Thoughts to “Sweet versus Bitter Almonds”

  1. Phil C.

    Most almonds are of the sweet variety, containing negligible amounts of amygdalin to begin with, so I would think there would be no difference between eating them raw or pasteurized. Does pasteurization have any effect on amygdalin content at all?

    Some sources say the cyanide is tightly bound in the amygdalin molecule, so amygdalin is essentially harmless in the bloodstream. In a living body, the cyanide radical is catalytically released by an enzyme called beta-glucosidase, which is not present in normal, healthy cells. However the enzyme may be present in the gut flora and is present in cancer cells. The cyanide can also be released with sulfuric acid, but that is not a concern when foods containing amygdalin are consumed. Amygdalin is found to a greater or lesser degree in over 1,000 different plant foods, not just almonds. It imparts a bitter flavor, and as plant breeders breed out the amygdalin content to satisfy consumer palates, cancer rates around the world continue to rise.

  2. andrina sofos

    We have baught two Halls Hardy Almond Trees from a Nursery in Carson City,
    Nevada. We planted them here in Reno and they are beautiful in the spring
    blooming great, But in the fall they produce these hard shell almonds which
    are hard to open, as they recommend a plier or hammer, or some type of Vise.
    But they are bitter. The Nursery people said that they are edible.
    Is there cyanide in these bitter almond and do they have to be boiled and roasted
    as some sites suggest.
    In the old country, Greece, they bake a lot with bitter almond, its their delicacies over there, even in my home town of Galaxidi Greece, they use
    this almond as a paste and serve it by the teaspoonful, its their specialty
    the women there make.
    All we want to know if it is safe to eat. Last year I cracked open a lot of them
    quite some time cosuming, and baked almond cookies,which are still in my freezer. Its a lot of work, and they are not the good size almond that youbuy in the store.

    I am concerned of the cyanide in them?

    Any input you can offer will help. Can they be grafted with a peach tree?
    A. Sofos

  3. Americans have lost all of their common sense. Wake up people! Humans have been eating bitter almonds and raw milk for thousand of years, AND STILL DO in other countries. Use your critical thinking skills and think it through. Don’t just follow the “leader” and believe everything they tell you. If the pharmaceutical companies can’t patent/profit on it, the government agencies will discredit and/or criminalize it.

  4. Steph Walts

    I been doing alot of research since my mother in law got cancer and am finding out quite alot of things. Raw bitter almonds contain vitamin B17 which is a cancer killer. Check the facts more than once, we’ve been lied to quite alot Im finding. There are more peeps makin $ off peeps with cancer than there are that actually have it. Fun Fact; microwaves are outlawed in other countries. If u put a cup of milk in the microwave for 1 min by the time u take it out 95% of the vitamins are destroyed along with u just filled it with radiation. Dont listen to mainstream, theyr not looking out for our best interest. I hope this helps open someones eyes

  5. Ryan Ehlis

    This is bullshit! the cyanide in almonds and fruit seeds is a chemical called vitamin B-17 and is very safe and healthful! The FDA is trying to scare people not to take it because it cures cancer! YES IT CURES CANCER! The cyanide is only released when it comes in contact with cancer cells in the body killing the cancer only, but doing no harm to surrounding tissue. This vitamin B17 has the ability to save millions of lives and bring an end to toxic noneffective cancer treatment! I have eaten hand fulls and it has not bothered me at all! Unlike chemo therapy that will kill you!

  6. Bruce McNeese

    I wish I could get the truth about eating bitter almonds vs sweet almonds. will eating bitter almonds kill you, or not?
    If so, will roasting remove the bitter taste and make them safe? Thanks.

  7. I have a Hall’s Hardy almond and got almonds last year. It is one of the few almond varieties that will produce here (they bloom early). Some nuts like cashews do need to be roasted before eating. All nuts benefit from some roasting (google times, etc) as it improves the flavor and storage length. Almonds can be successfully grafted onto peach and nectarine trees/roots.

  8. Kim delana

    I purchased a almond tree from the adobon society. Amount other trees. Not knowing I should have kept my info ……..Now I don’t know if it’s a sweet or bitter tree. How can I tell?

  9. Dino Martini

    Bitter almond blossoms are pink and sweet almond blossoms are white. Bitter almonds are totally edible once roasted. Bitter almonds are used in making marzipan although it only makes us 5% of the almonds used to make it. Almond macaroon cookies are best when they’re made with a small amount of bitter almonds. My parents were born in Italy and have been using bitter almonds safely for centuries. Grafting apricots onto almond root stock give the apricot a unique and wonderful taste. Does anyone know whether that particular fruit has a unique name in English?

  10. Cheryl

    How long do you need to roast bitter almonds in the oven for, to make them safe to eat?

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