According to "Scientific Criteria to Ensure Safe Food.", berries are allowed to be sold with 60% mold count:

TABLE D-1: Food and Drug Administration Levels of Natural or Unavoidable Defects in Fruit and Vegetable Products that Present No Health Hazards for Humans

Product Defect Defect Action Level Defect Source (Significance)
Berries, drupelet, canned and frozen (blackberries, raspberries, etc.) Mold Average mold count is 60% or more Postharvest infection

—Adapted from "Scientific Criteria to Ensure Safe Food." (2003)

How is this even possible? 60% would mean half or more the berry is mold, wouldn't it?

  • 1
    I don't know whether the laws are different in the US but in Germany in some stores or markets you can buy fruit/ vegetables that are clearly moldy or otherwise well beyond their best before date. They are heavily discounted and it is up the buyer to decide whether they can still use the good looking parts.
    – quarague
    Oct 14, 2021 at 10:08
  • 4
    @quarague Bear in mind that the fact that you can find moldy fruit at some markets doesn't per se tell us whether it is legal or not to do so.
    – JBentley
    Oct 14, 2021 at 12:12
  • 15
    this is more a misunderstanding of the language in a regulation than anything else.
    – jwenting
    Oct 14, 2021 at 12:17
  • 6
    While well-intentioned, I'm flagging this for improvement/removal. It's not challenging a claim.
    – Dancrumb
    Oct 14, 2021 at 21:00

1 Answer 1


According to the Food Defect Levels Handbook (FDA.gov):


Refers to the results of the Howard mold count method which is reported as the percentage of positive microscopic fields that have been scored as either positive or negative based on the presence or absence of a minimum amount of mold hyphae.

Many web pages describe the method as "standardized", but I haven't found a clear statement of the standard online. An article in an industry newsletter goes into more detail about evaluation of tomatoes, which are the fruit for which the method was first introduced:

The measuring cell into which the tomato paste is filled has a grid-shaped measuring field divided into 50 equal fields. Each grid field containing microscopically recognizable mold is evaluated. The Howard mold count is given as the percentage of positive fields in relation to their total number.

If blackberries, raspberries, etc. are evaluated in a similar way, then the presence of as few as 30 mold hyphae in a sample might be judged unacceptable, if they happened to be 30 different fields. On the other hand, the FDA document refers to a "minimum amount" and not "any amount", so the threshold for scoring a field as positive may be higher.

In any case, "average mold count is 60%" refers to small quantities of mold contamination seen under a microscope, and not to a product that is 60% mold.

  • 37
    So the 60% isn't the amount of mold, but the proportion of tested samples which show "a minimum amount of mold hyphae"? Oct 14, 2021 at 8:41
  • 5
    @WeatherVane correct. It doesn't mean the amount of mold per volume or weight at all, but the presence of any amount of mold at all on a number of samples. If the fruit is visibly mouldy it'd be inedible and therefore no doubt be illegal to sell under other rules even if it somehow managed to skip this requirement (unlikely though it is).
    – jwenting
    Oct 14, 2021 at 12:17
  • 13
    Regarding your first paragraph, the linked website is to NCBI, which, while part of the NIH, hosts a number of databases of third party content of use to scientific researchers. The listed book actual is a publication of the US National Academies, "private, nonprofit institutions that work outside of government to provide objective advice". -- They may be a reliable source, but not a governmental one, nor part of the NIH.
    – R.M.
    Oct 14, 2021 at 12:19
  • @R.M. I deleted the first paragraph, which was not appropriate for an answer anyway.
    – benrg
    Oct 14, 2021 at 19:25
  • 1
    @LangLаngС I added some more information. The method seems to be well known in the industry but I know nothing about it myself.
    – benrg
    Oct 14, 2021 at 22:17

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