Most of us obtain thick, rich fermented dairy using my method of prolonged fermentation and addition of prebiotic fiber. But some people occasionally obtain a foul-smelling end-result with grotesque separation into curds and whey. This is due to contamination from a foreign microbe obtaining access to your mix. Let’s therefore discuss how such contaminants enter the picture.

We call it “yogurt” even though, by FDA standards, it is not yogurt. By the FDA’s definition, yogurt is obtained by fermenting with Lactobacillus bulgaricus and Streptococcus thermophilus, two traditional but unremarkable species that yield little in the way of health benefits. Instead, we ferment using human-sourced microbes, especially species such as Lactobacillus reuteri that nearly everyone has lost due to its susceptibility to common antibiotics.

As the L. reuteri and SIBO Yogurt experiences have grown worldwide, we are learning new lessons on how people are introducing contaminants. Among the sources of contamination that we have identified include:

• Contaminated utensils—The most common culprit are devices like spatulas or stick blenders in which there are microbes living in the crevices and joints. In the spatula shown above, for example, contamination can come from where the wood inserts into the silicone or rubber.
• Contaminated bowls or jars—This seems to be a less common source, but consider if you dry with a used towel, leave the bowl open to air for extended periods, or simply failed to clean adequately. If, for example, you had potato salad or green vegetables in the bowl previously, foods contaminated by microbes, a small residue on an inadequately cleaned bowl could cause contamination.
• Preparation in the path of airflow—If a heating or air conditioning vent blows in the vicinity of your yogurt prep, it can become contaminated with fungal species. This won’t cause separation, but discolorations in orange, pink, green, or black. Just scrape off the discolored area and discard; the remaning yogurt is safe to eat, provided you don’t see discolorations deeper into the yogurt. One of my Inner Circle Members also found that her nearby oil diffuser was a source of contamination and had to remove it from her kitchen.
• Contaminated prebiotic fiber—I obtained the Certificate of Analyses on around 10 different commercial brands of inulin. Every one cited “<900 CFU/gram” of Bacillus species, most commonly B. cereus, a spore-forming species. B. cereus is ubiquitous and difficult to eradicate, as it is resistant to heat, UV radiation, and other methods that eradicate other species. Even boiling or baking will not kill B. cereus. Contamination with this microbe can cause food poisoning: abdominal discomfort, nausea, vomting, diarrhea within several hours of consumption. While <900 CFUs/g is not enough to make you sick, a tablespoon of inulin used to start fermentation yields around 13,000 microbes at the start, greater with fermentation that proceeds at approximately the same temperature as L. reuteri and other microbes we ferment.

That last item—contaminated prebiotic fiber—is the toughest of all to deal with. Should you suspect that your foul end-result is due to contamination, consider getting a new batch of inulin. Unfortunately, that is no guarantee that the next batch of inulin won’t be contaminated, also. You can boil your yogurt mixture before adding microbes, but that only kills non-spore forming microbes, not Bacillus. I therefore explored whether we should irradiate the inulin, e.g., UV wavelengths, but the logistics of doing so were prohibitive (since UV has poor penetrating power and you would have to expose the inulin as a very thin layer for several hours). I recently found a supplier, however, who provides the inulin sterile. We submitted for confirmational testing and it was indeed sterile. I will be making this available to everyone in coming weeks.

Another potential solution that we’ve been toying with is to start a batch with higher counts of microbes, e.g., 40 billion of MyReuteri. That way, you may have potential to “overpower” any contaminant.

Source: Stop contaminating your "yogurt" - Dr. William Davis (drdavisinfinitehealth.com)