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The Truth About Almond Pasteurization Methods

While there are four main methods of pasteurizing almonds, steam processing, high heat treatment (roasting), blanching and highly toxic fumigation treatment with propylene oxide (PPO), two of them are the primary methods that are used most often.. These two are steam processing and PPO fumigation.

Steam processing is the method delineated to the organic sector of the almond industry. While this is probably the cleanest method of pasteurizing almonds it is still an option reserved for those who have the budget to use machines like this.


As you can imagine, most organic almond farmers likely do not have the budget or the desire to invest in this type of equipment leaving their only option being contracting with other businesses that do have this type of equipment. Of course this is unrealistic because the farmers will have to transport their entire harvest from their farm, to the facility where this equipment resides (that could be anywhere in relation to where their almond farms are located) and then back to their farms before they can even prepare their harvest to be sold to their customers. The extra expenses this adds to the production of the almond crops eats a massive potion of the profit (if not all of it), making it a losing option for most producers and that is assuming they have access to this type of equipment, which most don’t.

“On top of this unrealistic expectation on organic farmers as assumed by the USDA, the farmers are then left with almonds that have been Steam processed using surface treatments. Multiple proprietary steam treatments are currently being utilized by the industry which meets USDA Organic Program standards. Regardless of claims to the opposite, these short bursts of steam do indeed impact the nutritional integrity of the almond. These treatments do not heat proteins-and diminish vitamins and minerals. The nutritional and sensory characteristics of the almonds ARE changed when treated with steam.

They are exposed to steam for 8 seconds at 210-215F. Then for 44 seconds they are moved through a high-heat dehydration tunnel to remove the moisture resulting from the steam. The circulating air temperature is 391- 395F. During this process the almonds reach 220-221F. This eliminates both good and harmful bacteria and also reduces critical enzymes, vitamins and minerals. ” www. preventdisease.com This has been the fate of countless organic Californian almond growers who have been subjected, with no say whatsoever to the 2007 federal mandate dictating their immediate implementation of steam pasteurization.

Due to how quickly this mandate occurred, most almond farmers were not able to comply, leaving them literally in the dust. Millions of dollars that once supported the thriving organic almond industry had now been averted into the hands of big corporate almond producers and pasteurization equipment producers.

The second primary almond pasteurization method is called propylene oxide fumigation(PPO).

PPO is the pasteurization method reserved for non-organic almonds. PPO is a chemical so nasty it was banned by both the American Motorcycle and the National Hot Rod Associations, where it had been used as a fuel before they recognized how dangerous it actually was. PPO is a verified carcinogen that is highly flammable with noxious fumes that are incredibly hazardous to a human beings personal health. Even the EPA has declared PPO a carcinogenic chemical that is responsible for neurological, gastrointestinal, respiratory, immune system dysfunctions and liver disease, to name a few.

In addition to the American Motorcycle and National Hot Rod Associations banning it, countries such as Mexico, Canada and the entire European Union have banned it because of its known carcinogenic risks to human beings!

Here is a hazard summary as reported by the EPA:

“Propylene oxide is used in the production of polyethers (the primary component of polyurethane foams) and propylene glycol.  Acute (short-term) exposure of humans and animals to propylene oxide has caused eye and respiratory tract irritation. Dermal contact, even with dilute solutions, has caused skin irritation and necrosis in humans. Propylene oxide is also a mild central nervous system (CNS) depressant in humans.  Inflammatory lesions of the nasal cavity, trachea, and lungs and neurological effects have been observed in animals chronically (long-term) exposed to propylene oxide by inhalation.  Propylene oxide has been observed to cause tumors at or near the site of administration in rodents, causing fore stomach tumors following ingestion via gavage (experimentally placing the chemical in the stomach) and nasal tumors after inhalation exposure.  EPA has classified propylene oxide as a Group B2, probable human carcinogen.”

Even if you are a person who cares less whether your US grown almonds are pasteurized or not, do not, I repeat DO NOT eat non-organic almonds grown on American soils unless you also don’t mind subjecting yourself to a chemical so toxic that its use was banned by National Motorcycle and Hot Rod Associations!



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  1. So does other almond products such as almond milk or almond butter contain this ppo

    • Hi Jackie- PPO may be used to pasteurize non-organic almonds- so yes any product made with those treated almonds contains PPO. Organic American almonds do not use PPO- but they are still pasteurized. We use European almonds which are not pasteurized.

      • I bought Raw Almonds from Trader Joes and they are not organic but they say they use the steam method of pasteurization. I soaked them and they began to sprout. Does that mean that they have live enzymes and have not lost nutritional value? Or is the fact that they sprouted irrelevant to their enzyme content and nutrient value? Thanks very much!!

        • Hi Sirah.
          Organic almonds are always steamed pasteurized, whereas, with non-organic- there are two main methods being used to pasteurize the almonds. One uses steam to sanitize the nuts, while the other uses the chemical propylene oxide, aka PPO, which is considered a possible carcinogen. Since pasteurizing with PPO is the standard in the industry and it is cheaper than pasteurizing with steam, many non organic growers use this method, but some may use the steam method. I would be make sure that they do!
          The other problem with non-organic almonds is that pesticides are used to grow them and almonds (since they have a high oil content) absorb these pesticides in higher amounts- http://www.whatsonmyfood.org/food.jsp?food=AL.
          We have heard some success in sprouting with steam-pasteurized almonds, but others say they have a hard time. And finally, some say the taste and texture of steam-pasteurization is not as good as raw:
          “When the law came down, Glen Anderson pasteurized a batch of the organic almonds grown on his farm in Hilmar, south of Modesto, in Northern California. He says steaming the nuts changed the moisture and taste of his product.The acute flavor that I’ve grown to expect in a good, organically grown almond just isn’t there,” says Anderson. The taste, he says, “leans towards cardboard, http://www.npr.org/sections/thesalt/2015/05/19/407760579/what-does-raw-mean-when-it-comes-to-almonds-you-might-be-surprised as opposed to fresh almonds.
          As far as the nutrition value- it depends on who you ask: “Heat pasteurization can change the composition of lipids (fats) in the nut, making them less healthy for our bodies, says Jayde Lovell, a science communicator and the producer of Did Someone Say Science? When heated to a certain temperature, fats and oils oxidize—which means they break down and acquire extra oxygen molecules that lead to spoilage. Whether this is a bad thing is a subject of debate. https://www.honeycolony.com/article/why-arent-our-almonds-as-healthy-as-before. Hope this helps…..SP

  2. I just purchased whole almonds …Kirkland brand from Costco..product of USA…they
    Are steam pasturized…..can you tell me if they are safe,,,,,I want to make almond
    Butter,,,,the recipe called for raw whole almonds and it said to soak overnight, dry
    And roast ……….thanks

    • Hi Sheila- Sorry for the late response. If the almonds you purchased are not organic then likely they are chemically pasteurized. I would buy only organic almonds, however with that said, any almonds you buy in a store that are organic have to be steam pasteurized by law. It will not harm you, but the nutrient value may have been altered. Hope this helps!

      • ALL natural almonds sold in the United States must be pasteurized. This is a federal regulation. I’m not sure what you mean by the term ”fresh” almonds. That’s not a condition or term used in the industry and almonds that have not been pasteurized or roasted to achieve the kill step may not be legally sold.in this country. Also, most farmers sell their raw crops to a licensed handler who completes the pasteurization step and processes the almonds further according to USDA GRADE requirements to prepare almonds for market. The farmers themselves do not do this. Pasteurization, steam or otherwise, is not a cost born by the farmer.

        • Hello- we any use organic almonds from Europe as they are not pasteurized. Thank you.

        • My understanding is that you can buy unpasterurized almonds directly from the farmer. Please clarify this for me. Thanks!

          • Hello- I am not sure of the process of buying straight from the farmer.

  3. Not sure if my question was submitted on previous attempt so I’ll repeat the submission.
    Do the almonds from Europe you buy go thru a radiation process? as that seems to be what Europe does to pasteurize food.

    • Hi Randy- (from our website) and thanks for asking! Some people are under the assumption that all foods that are imported into the US must be irradiated or pasteurized. This is simply not true. The only reason that customs will irradiate organic food is if there is something to suggest the need for it ie: pathogen, mold, bug infestation, etc. Then, customs will contact us because we are responsible to pay for the irradiation, under which case we will deny the shipment and the eat the cost. That is why we are very strict with our suppliers in making sure that they send us the highest quality product possible.

  4. Are unshelled nuts safe to eat and what process is used on them?

    • Yes, they are totally safe! Most nuts are shelled as soon as they are dried thoroughly at the location they are grown! We sell them Raw and also soaked in water to start the germination/sprouting process for better digestion and mineral absorption

  5. Could you tell me whether soaking nuts in salt water would remove the PPO residue that is left on the almonds? Or does it actually soak in to the almond meat itself? Also, do blanched almonds go through the same pasteurization process? Thanks for your information!

    • Hi Sally
      Don’t know if soaking nuts in salt water would remove PPO residue. Your healthiest option is to stay away from non organic almonds from California. Even organic almonds from California are pasteurized if you buy them from stores- but they steam them, instead of using chemicals. We get our almonds from Europe as they are not required to be pasteurized. Blanching is a different process than pasteurization. Hope this helps!

    • did you ever find out if you can remove PPO residue?

      • Hi Sally- We don’t have PPo residue on our almonds as they come from Europe and not pasteurized like U.S.Almonds

  6. Recently Helen Caldicott,PHD. in a report on radiation advised not to eat any foods from Europe. Where do you get nuts outside of the USA?

    • Hi Joyce. We get our almonds from Spain and Italy. We listened to Helen Caldicott presentation as well. We also did some research too. The Chernobyl radiation fallout affected mostly Eastern Europe and Scandinavia. Incidentally, The more recent radiation from Fukushima is affecting the west coast now (http://enenews.com/category/u-s-canada/us-nuclear-facilities/west-coast). California, is the largest producer of almonds, except they are pasteurized now (both organic and non-organic).

      • May you please share the Helen Caldicott link. I would love to listen to it! Thank you so very much.

  7. I would like to see the evidence based research articles where you found this data regarding the high content of acrylamide in steamed almonds. I have not been able to find this information. Thank you!

    • Hi
      This article was written 4 years ago- so I am not sure if they were using a specific steam method of high heat? I know they made advances in steam technology. I therefore updated the article with respect to this technology (from preventdisease.com) There was also talk about a year ago that all nuts produced in the US would be pasteurized and public opinion was being sought. I haven’t heard anything new regarding this. Thanks for writing to us.

  8. Hello there! I could have sworn I’ve been to this blog before but after checking through some of
    the post I realized it’s new to me. Nonetheless, I’m
    definitely delighted I found it and I’ll be bookmarking and checking back frequently!

  9. Is it possible to grow almond conventionally (not certified organic) but remain unpasteurized? What are the differences between conventionally grown unpasteurized and organic almonds? Which kind has more nutritional value?


  10. i eat only organic nuts, and now i am about to order directly from you (thanks for the great article!) but i am wondering where you get the research that says steaming causes acrylamides? i have not found this information anywhere else, and am very curious.

    • Hi Lisa.
      Not sure where you found that info- What I found in one of our bogs is that roasting causes acrylamindes- here is the quote:
      Scientists have tested for possibly harmful levels of acrylamide, a threatening by-product produced from the amino acid asparagine, in roasted nuts such as Almonds and Hazelnuts. In addition, acrylamide is a chemical that can form in some foods during high-temperature cooking processes, such as frying, roasting, and baking.

  11. So I have been eating garbage for the last year? Makes me so mad. love your sight. thanks.

  12. Thank you!

    I also read that blanching and roasting takes care of the pasteurization issue. Is this correct?

    • This from the almond board:
      To date, FDA has approved oil roasting, dry roasting, blanching, steam processing and propylene oxide (PPO) processes as acceptable forms of pasteurization for almonds. Hope this helps!

  13. Hi Seth,

    Interesting tid bit on the pasteurization process of almonds. You mention the cost involved with pasteurization. Specifically, that most small organic farmers do have the financial ability to purchase pasteurization machines and therefore would need to truck their entire farm to a facility with the capacity to do this.

    So my question is this. How do the almonds get to your facility? From what I know they need to be shelled and not every organic farmer has the ability to own these shelling machines. Do you shell by hand? Or do the truck the almonds to a facility that shells and then send them elsewhere to be cleaned and then finally sent to the teams that package and distribute?

    Just looking for a little bit more info.

    Keep up the good work.

    • Jacob. We actually import our shelled almonds from Europe because all U.S. almonds are pasteurized by the methods previously stated. We do not believe almonds should be pasteurized and that pasteurized almonds are not raw. We know this has been a hardship on small farmers. The Cornucopia Institute has been on the front lines on educating people about this topic. Thanks for contacting us…

  14. How about drinks made with almonds?Do companies like SilkPureAlmond use the same kind of pasteurization methods?

    • Hi Katia,
      In response to your question. any U.S. handler of almonds (like manufacturing companies that process almonds) must either use pasteurized almonds grown in the U.S. or submit their own treatment plan to be approved by The almond board. The board only approves certain methods for pasteurization. So in essence their almonds are pasteurized- but may differ from the pasteurization methods on the growers side.

  15. Can anyone tell me what happens to the enzymes once the steam pasteurization has been done?

    • Our research shows that through pasteurization the shelled and hulled almonds are steam treated with temperatures up to 200 degrees. Not only does this high heat kill any pathogens that are present, it destroys the value content of the nut itself. Any time a food is heated above 115 degrees, vital enzymes are depleted.
      Thanks for your question

    • Cassie,
      Studies have suggested that enzymes are destroyed during the heating process

  16. Thanks for asking! Our almonds are from Europe where they do not pasteurize the nuts. Most almonds in the U.S. are pasteurized, unless you buy it directly from the farmer at a roadside stand (limited amount), according to the U.S. almond board. Additionally, all our nuts are certified organic too!

  17. Yes, that appears to be true…Thank you for your comment!

  18. Yes- that is why it is important to check the source for the food and to make sure it is certified organic.Thank you

  19. Thank you

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