Saturday, May 11, 2013

Rye Contamination In Wheat

I have some rye contamination in a wheat field that is being grown for fine SRWW or soft red winter wheat flour.  I can rogue the heads out but how bad is rye contamination in a load of soft red winter wheat?  Is it a small problem or a large problem?

Rye contamination is not uncommon in wheat production.  Where we use so much cereal rye for cover crop, there is always the possibility that some rye could escape our management practices and show up in the wheat.  In certified wheat seed production, rye is a no-no.  The field must be rogued of the rye or the field is disqualified for seed.  If it's disqualified, it goes into the wheat supply.  How does the miller deal with it and how much of a problem is it?

Many wheat flours contain some rye and many rye flours contain some wheat.  It is not like the joke about garlic showing up in a load of wheat and should not be discounted because the miller can make garlic flavored crackers out of it.  It doesn't work like that.

"I am not sure if or how significant this problem might be in commercial wheat grain fields. Each year we receive a few calls on identifying Rye in wheat fields. This usually results from fertilizer spreader contamination in the course of top dressing fields.  Furthermore, over many years of attending the Soft Red Winter Wheat Researchers Conference, I have not heard research or technical papers presented on this issue. In commercial wheat, rye grain is a dockage contaminant and high levels result in discounts.

Rye flour has its own characteristics for baking and the baking industry obviously prefers uniform soft red winter wheat flour that has low or no problems with Mycotoxins (Fusarium) infested wheat grain and has other desirable levels of protein, break flour yield and cookie diameter quality factors. Lastly, the milling industry in Ohio, to the best of my knowledge, does not utilize Identity Preserved grain programs for field or post-harvest sample inspection, so OSIA has no file data on this issue. Another question relates to the potential and extent of  other GMO crop contamination in wheat grain, introduced by un-cleaned harvesting, storage and conveying equipment."

A farmer had a question about rye in wheat this morning.  I answered "There is more rye in wheat than usual this year. I was wondering what happens to the wheat flour if milled. Contamination is common and wheat is usually in rye bread and rye is often found in wheat bread. SRWW is pastry dough though so contamination would potentially be a bigger problem.

Volunteer wheat and rye is both fairly common around here. A shot of grass herbicide in the fall and early spring helps control it. Most rye kernals are smaller than wheat so they will be separated to a point but the contamination is going to be in the grain and in the field no matter what we do.

It's a big no no in seed wheat of course so the field is inspected for seed and will be rejected with rye heads at harvest."

Do you see any rye or other contaminants in wheat fields this spring?"



  1. From a friend in Missouri, "It is a concern but remember there is Italian Ryegrass, Tetraploid annual ryegrass, and diploid annual ryegrass. The safest to use as cover is "Bounty" annual ryegrass a diploid. No telling which of the 3 the original poster or subsequent posters have w/out more info. The gents in the south probably have either Italian or Tetraploid as they have been used in the south for forage."

  2. From another friend in MO. HHhhmmm Unsure how safe it is. Only hope it is safe. Variety unstated, and blends will get some in trouble. Safest way I know, don't use it.

  3. The FDA has tolerable level of all kinds of bad things..

    The Food Defect Action Levels

    Wheat flour Insect filth Average of 150 or more insect fragments per 100 grams

  4. Yep, looks like the thread is about rye-grass, not rye.
    Rye-grass is probably the "tares" weed mentioned in Matthew.
    The generic French name of the species is also the name used in the Bible, and gave us the words "enivré" and "inebriated" (from the same Latin root), from the slightly toxic seed of the darnel weed.
    Even if plain rye-grass, not darnel, it is sometimes infected by a fungus that is slightly toxic to cattle.

    There is still a common expression "to separate the wheat from the tares" in French, from the same Matthew parable, but somehow it changed to "chaff" in English.
    The Greek name for darnel persists in another French expression "to sow tares" ("semer la zizanie") meaning to sow discord, and in the genus name for wild rice, zizania. Funny biologists...

    Rye is not welcome in wheat because of its susceptibility to the highly toxic ergot, which hippies said in the 60-70s has an effect similar to LSD, called St. Anthony's Fire since the Middle Ages.

    So, rye-grass or rye, none is welcome in wheat.
    No possible confusion in French, rye is "seigle", "rye-grass" is "ray-grass", probably imported and "Frenchisized" together with the British perfect lawns.


    WHEAT Insect damage
    (MPM-V15) Average of 32 or more insect-damaged kernels per 100 grams
    Rodent filth
    (MPM-V15) Average of 9 mg or more rodent excreta pellets and/or pellet fragments per kilogram
    DEFECT SOURCE: Insect damage - preharvest and/or post harvest and/or processing infestation, Excreta - post harvest and/or processing animal contamination.
    SIGNIFICANCE: Aesthetic

    WHEAT FLOUR Insect filth
    (AOAC 972.32) Average of 75 or more insect fragments per 50 grams
    Rodent filth
    (AOAC 972.32) Average of 1 or more rodent hairs per 50 grams
    DEFECT SOURCE: Insect fragments - preharvest and/or post harvest and/or processing insect infestation, Rodent hair - post harvest and/or processing contamination with animal hair or excreta.
    SIGNIFICANCE: Aesthetic

  6. I think I would rather have rye than that in my wheat flour too, Brad!

    Good post.


  7. Chimel, your post is excellent, too. I did not know that per se but what you wrote makes good sense.

    How do you find all of this stuff?


  8. I was raised on Belgian comics, like Tintin and Asterix the Gaul.
    This one is called La Zizanie in French:
    So I had to look it up. But the expression "to sow zizania" is quite common.

    You are the one responsible for triggering these memories! ;)

    First came Matthew's Parable in Bible school as a kid, but didn't look it up until after studying farming. Met ergot around that time too, I was cataloging all plants with a possible usage since a teen, and that included plants with psychotropic effects, even though I never consumed shrooms or even pot.

    By the way, you were saying gardening is the best gift you can make to your kids and grand-kids, but Tintin and Asterix and Lucky Luke really build up a family (and national) culture too. Even today, I still use arcane expressions that were born in these comics and are immediately understood by most French people. Captain Haddock has a range of dozens of almost politically correct expletives like "waffle iron" that would delight any kid too.

    Tintin: The adventures of a reporter and his friends, fighting against oppression and illegal trades.
    Asterix: The adventures of a Gaul and his village at the time of the Romans. Great way to learn about the Roman culture, even translated into Latin!
    Lucky Luke: The adventures of a cow-boy and his horse in early America.

    I own full series of most other Belgian/French comics too, they are unlike anything else in the world, including American comics, with great drawing artists but great stories too.

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