Gluten-free oat production: Purity protocol versus mechanical or optical sorting: Does it matter to you?

Gluten-free oat production: Purity protocol versus mechanical or optical sorting: Does it matter to you?

We are in a new era of gluten-free oat production. Gone are the days when oats and oat products labeled gluten-free meant the grain was produced under a purity protocol. Single- and multi-ingredient oat products labeled gluten-free may now include “regular” oats that have undergone mechanical and/or optical sorting to remove wheat, barley, and rye grain (this is now true in both the US and Canada). Many in the gluten-free community are in the process of working through this brave new world of gluten-free oat production and wondering whether sorting is as good as a purity protocol. Some of us are worried that the use of cheaper “regular” oats by gluten-free manufacturers may mark the end of the availability of more expensive gluten-free oats produced under a purity protocol. Whether we continue to have available to us oats grown under a purity protocol is largely up to the gluten-free community and how we choose to spend our dollars.

Gluten Free Watchdog Position on Oats as of June 17, 2015: Gluten Free Watchdog supports the use of gluten-free oats by the celiac disease community that are produced under a purity protocol. At this time we do not support the use of regular oats that are cleaned at the “end” of production via mechanical and/or optical sorting to be “gluten-free.” Before we can support the use of oats “cleaned” in this manner to be gluten-free we must be provided with thorough testing data. We can then compare this data to the thorough testing data provided to us for oats grown under a purity protocol.

Note:  I will be meeting with General Mills in July to discuss gluten-free Cheerios. This meeting will be between General Mills and me and will take place at their new mill facility–it is not another “Cheerios Forum.” Those who are involved with testing oats/Cheerios for gluten at Medallion Labs also will be present. General Mills has been advised that it is important to provide me with detailed information about their testing protocols as well as allow me to view test results. This is necessary so that years of testing data on oats produced under a purity protocol can be compared to testing data on oats “cleaned” at the end of the production process using mechanical sorting. Gluten Free Watchdog will also be testing gluten-free Cheerios once they are available.


Gluten Free Watchdog recently learned about the companies Marshall Gluten Free Milling and Pro-Cert. Read on for more information about oats grown on certified gluten-free farms.

Q: Michael, please tell me a bit about yourself and your company.

A: My name is Michael Marshall and I am the President and C.E.O. of Marshall Gluten Free Milling ( After 15 years of working in the natural and organic grain and food ingredient business doing every job there is from sweeping the floor to being general manager of entire operations, I decided that it was time to make a difference in a segment of the marketplace that needs some help. The gluten-free space has become a feeding frenzy for companies capitalizing on it so much so that I saw a post on Facebook of someone selling gluten free haircuts… That frustrated me. I understand that for folks with celiac disease, eating gluten-free isn’t a choice.  It is not the “next flavor of the week.”

Q: What does Marshall Gluten Free Milling do?

A: We are the world’s first company that provides ingredients to manufacturers that are produced on third party Certified Gluten Free FARMS by Pro-Cert a worldwide leader in third party organic certification. It is a program that closely mirrors organic certification. Each farm must be free from gluten-containing products for two full years and on the third year of production the crops can be marketed. No gluten-containing product can be stored, handled, transported or conveyed with any infrastructure or equipment on the farm. Marshall GF Milling staff then control the dedicated trucking to a gluten-free only certified cleaning facility where the product is cleaned and sized to maximize quality. The oats are then shipped in a dedicated gluten-free truck to a third party certified gluten-free mill (GFCO, PRO-Cert, etc.). So the mill, cleaner and farm are all certified.

Q: What crops are available in your program?

A: Organic oats and flax at present. However interest has spread to non-organic producers as well. We are expanding the offerings to lentils, peas and possibly quinoa. We need to keep a sustainable crop rotation for the producers in the program. Primarily right now the focus of our ingredient marketing is oats as this is where the 3rd party certification of the farm is most crucial to developing a sustainable gluten-free crop rotation.

Q: Recently General Mills announced that five varieties of Cheerios will be labeled gluten-free. The company is using regular oats cleaned at the “end” of production via mechanical separation. According to General Mills there are not enough oats grown under a purity protocol to produce Cheerios. Based on your industry experience, do you feel that mechanical/optical sorting is sufficient to ensure the gluten-free status of oats?

A: General Mills is a trusted brand; they value their name. I am sure they have done their homework on the process. In my experience in the grain business and within the food industry, mechanical and optical sorting equipment has been used for quality control as well as for food safety precautions for years. I wouldn’t call it a new idea. The technology has come a long way but I think even General Mills would have to agree it does not reduce the risk to zero. In particular, I have concerns when it comes to dust residue. However, I do not know the dust control system used by General Mills. In my opinion, using contaminated conventional low cost oats in gluten-free foods is risky.

To address the shortage of oats grown under a purity protocol, I would answer that with a question… If General Mills could purchase 3rd party certified gluten-free oats from the farm, would they buy them if the volume needed was available?

Q: Does your program guarantee 100% pure gluten-free oats?

A:  Frankly speaking there are always going to be anomalies. However, if you look at the protocols in our program there are standard operating procedures in place. These procedures include:

Planting seed that is verified pure.

Using gluten-free only planting equipment.

Using buffer strips around the field–At harvest, the crop within the buffer strip cannot be binned with the gluten-free product (this protects the gluten-free crop from outside contamination).

Strip testing every load that comes off the field before it is binned.

Sending a representing sample from every bin to the lab for testing using the R5 ELISA R7001 assay (testing occurs prior to the crop being shipped to the mill).

Testing at the mill before the crop is unloaded.

The bottom line is that we use testing at various steps in our SOPs to find gluten through the entire production of the crop to mitigate or eliminate the risk of contamination before it even gets to the mill. Once at the mill hi- tech sorting or mechanical separation will be for quality versus the only fail-safe measure to assure removal of gluten.

Q: With all the steps that are required of the farmer to be certified gluten-free by Pro-Cert it must increase the cost of oats significantly. Can you comment on that?

A: The answer is yes but not significantly. But they do cost more than regular oats. The producer is paid more for the additional time, resources and expense needed to produce under these protocols. I would say that under a program like this there is little volatility from year to year because it is a closed loop system so consumers shouldn’t expect huge spikes in the price that never come down and just seem to go up.

Q: How can you compete with General Mills or other companies that use regular oats and clean them at the back end of production (i.e., once they arrive at the mill) to be gluten-free?

A: That’s an easy question… We can’t, and quite frankly I’m not making Cheerios. If you have celiac disease and you want to eat Cheerios that are labeled gluten-free and you trust the brand, please eat Cheerios. If you want to eat oatmeal produced from oats grown under the Marshall Gluten Free Milling Program that are audited and inspected, and you trust that every precaution has been taken to assure you have a SAFE gluten-free product that has been 3rd party certified all through the system from before the seed is planted until it gets into your bowl, then buy our product. The cost per serving at the end of the day whether you eat a serving of Cheerios vs. our oat products is still much less than a dollar. At the end of the day the individual is the only one that can decide if they feel good eating either product.

Q: So in your opinion, how do you and the millers following a purity protocol stay in business and how can the gluten-free community help?

A: It is difficult for companies that exclusively buy and mill gluten-free oats to compete and keep a reasonably priced healthy oat product. It’s specifically hard to compete with other millers who choose to mill cheaper “regular oats” cleaned via mechanical and/or optical sorting and sell them as gluten-free.

I believe that the gluten-free community can help by understanding what the process is, realizing that if you start with the purest of pure product that is monitored and certified by a third party prior to processing and you protect that integrity through the entire process, you can rest assured that every effort has been made to give you a truly gluten-free oat product from the field to your bowl.

Q: How do consumers know the difference between oats grown under a purity protocol and oats that are cleaned at the backend of production?

A: Education and advocacy from respected people in the celiac disease world. The message has to get out that there are different types of gluten-free protocols. Not all of them are created equal. People with celiac disease have to make decisions regarding brands they will trust.

Q: Some people might say you have a lot to gain financially from this endeavor and some may be skeptical of your motives to take advantage of the gluten-free market. Can you please comment?

A: With full disclosure I will say this is a business that I want to be successful… but it has got to work for everybody. If the prairie farmer can create a niche and provide a sustainable living by producing only gluten-free products for our company to manufacture and market and people with celiac disease can have a healthy and safe alternative they can trust relative to what is on the market now and we can all be healthy and profitable then we all win. If any other miller wants on board we would be happy to put a program together to supply Pro-Cert gluten-free farm certified oats. We have 25,000 acres of both organic and conventional farmland under the certification program that will be available for the market in October. There are farmers lining up to get on the program and we haven’t even marketed it yet. It’s a big market to supply and I believe we can all benefit.

Thank you, Mike!

© Copyright June 2015 by Tricia Thompson, MS, RD for Gluten Free Watchdog. All Rights Reserved.


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Comments (6)

  • Donna Bruton Reply

    I am so thankful for the research you are doing in this area. I have a bag of Chexs gluten free granola mix – honey nut flavor – in my pantry right now. It is a General Mills product. Now that I am reading about this, I wonder about the source of the oats. Since the bag said gluten free, I thought it would be okay, but I was disappointed not to find anything about certified gluten free. Now that I see General Mills is the owner of Chex brand, I’m not sure my daughter, who has celiac, should eat this. I sent GM a letter today and asked them about the source. As i was looking on their website, I saw how many brands are GM, including Immaculate Baking, Annie’s, Larabar, Chex, etc. Are there other brands that have the conventionally grown and then cleaned oats in them or is it just Chex and Cheerios? Thank you so much!

    October 23, 2015 at 11:49 pm
  • James willis Reply

    I’m plowing up 400 acres of brush virgin ground near southern idaho would i be good candidate to produce gluten free oats is anyone out there willing to contract?

    November 25, 2015 at 2:21 am
    • Tricia Thompson Reply

      Hi James, My recommendation is to contact Marshall Gluten-Free Milling or GF Harvest for advice.

      November 25, 2015 at 1:27 pm
  • Pam Reply

    My question is : how can the consumer possibly know what companies use gluten free seeds OR cleaned grains? Shouldn’t companies label accordingly so consumers don’t have to second-guess?

    July 8, 2016 at 12:41 pm
    • Tricia Thompson Reply

      Please see

      Gluten-free consumers:

      If you want to know the source of oats in your gluten-free products, contact the manufacturer and ask.
      Do not assume that oat products bearing a certification seal from GFCO, GFCP, or NSF are purity protocol oats. None of these certifying bodies prohibits the use of mechanically/optically sorted oats.
      Manufacturers may be sourcing oats from two different suppliers; one may supply purity protocol oats and the other may supply sorted oats.
      If purity protocol oats are important to you, ask whether ALL oats are sourced from a supplier of purity protocol oats.

      July 8, 2016 at 2:04 pm
  • d. howell Reply

    I was wondering if there is any data that tell what percentage of us with celiac would be able to notice a difference in our health when we consume purity protocol oats versus mechanically/optically sorted oats? What percentage of us would have different biposy or endoscopy results depending on which type of oats we consume? Are there studies that show that most of us will have problems unless we consume only purity protocol oats?

    September 21, 2017 at 10:53 pm

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