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Why doesn’t it mold?

Month-old commercial bread — no sign of mold

A month ago I bought a loaf of commercial bread for my annual ritual of the year’s first garden-tomato sandwich. Today I found the leftover bread on top of the refrigerator. There is not the slightest sign of mold. The bread label boasts that the bread contains no preservatives — at least no “artificial” preservatives. What is going on?

I found that, if I Googled for “Why doesn’t bread mold?” there were a lot of conflicting and confusing answers. I changed Google’s search parameters to show links less than a year old, thinking that there must surely be something new involved, and then the answers started looking more plausible.

The bread contains an ingredient called “cultured wheat flour.” That, I believe, is the magic ingredient.

It’s not clear how long “cultured wheat flour” has been in use. I suspect that it’s for less than 10 years. Clearly it is effective at preventing bread from molding. It is made from wheat flour that has been fermented with a bacterium called Propionibacterium freudenreichii. According to an article at BakerPedia, this bacterium is found in dairy foods including Swiss cheese, so it has been around forever and can be considered safe. According to the article, it is as effective as chemical preservatives at inhibiting mold. “As a result,” said the article, “it is growing in popularity in all natural and organic products.”

This bread is from a baking company called “Nature’s Own,” which is owned by Flower’s Foods. This bread is sold not only at my nearest Whole Foods in Winston-Salem, it’s also sold into the very bottom of the market — Dollar General stores. Apparently Whole Foods is satisfied that the bread passes muster.

The calcium-containing ingredients near the end of the list, by the way, are leavening agents that fizz when combined and are probably nothing to get terribly excited about.

The question I was trying to answer was whether it would be safe to give the leftover bread to the chickens. I think that the answer is yes. It’s scary, actually, to eat a food that resists being biodegraded. But fermentation is a natural process that does exactly that, and humans have taken advantage of fermentation as a way of preserving food for thousands of years.

Dissenting views? Please comment…


  1. DCS wrote:

    That’s the brand of bread that I get for Frank (I don’t eat bread), and the brand is available at every Food Lion from Winston to Wilmington. It has not killed Frank, and it has not killed the birds that eat all of our leftovers, so I guess it’s safe for your chickens.

    More seriously, that ingredients list does not look bad — i.e., overly long and complicated — for store-bought bread. I’m surprised there are not more unpronounceable words at the end. 🙂



    Saturday, July 29, 2017 at 5:43 pm | Permalink
  2. DCS wrote:

    There is more information about all of this in the book “Wheat Belly” by William Davis, M.D., here:


    Saturday, July 29, 2017 at 5:55 pm | Permalink
  3. Dan wrote:

    I agree with DCS; the list of ingredients doesn’t seem to contain anything too out of the norm. I would look to see how many grams of sugar servings have and maybe compare with other similar brands to see if its in the normal range.

    Our Sara Lee honey wheat, the kids’ favorite for PB and honey sandwiches, usually starts to mold about three weeks after we’ve unsealed it for the first use, when maybe only the last two or three pieces of the loaf are left. I normally don’t mess around even if it hasn’t been that long and throw it out anyway.

    Saturday, July 29, 2017 at 7:26 pm | Permalink
  4. Dan wrote:

    FYI – the Sara Lee we have has a few more big words but not many more, 2gs of sugar, 110mg of sodium.

    Saturday, July 29, 2017 at 7:30 pm | Permalink
  5. daltoni wrote:

    Dan, do the Sara Lee products also contain “cultured wheat flour”?

    Saturday, July 29, 2017 at 7:36 pm | Permalink
  6. DCS wrote:

    Very informative article about commercial bread-making processes here:

    You’re such a skilled bread-maker, guess you should stick to making your own if you truly want to control ingredients 100 percent. Otherwise, it looks like a crap shoot in terms of what chemicals go into bleaching the flour.


    Sunday, July 30, 2017 at 10:30 am | Permalink
  7. Dan wrote:

    I did not see cultured wheat flour on the list. There’s enriched wheat flour and whole wheat flour.

    Sunday, July 30, 2017 at 4:47 pm | Permalink

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