It’s been established in the last two posts that water bath canning preserved food by creating an isolated environment, protected from oxygen, hostile to bacterial growth. On the other hand, fermentation using lacto acid bacterias are open to exchanges with their environment – they change and develop character according to their conditions. Like us as children and adults, early on they may appear as a beautiful vegetable, but by the time they reach maturity they have gotten weird and smell.

Safer than a bank

Not unlike water bath canning it’s very important to do things properly for both your own safety and to make a product that’s pleasant to eat, but calm your damn self and be aware that your ferment is going to probably be very safe. The smells and textures of fermenting meat, fish, and vegetables can be incredibly off-putting to those who haven’t grown up around them – enough so that they may question the safety of ingesting them. These are very old methods of preserving: a little bit of experience will tell you for sure if you’re doing it right or wrong.

The author has had to defend his moldy cabbage to multiple chefs and more than one health board. From experience, if you’re confident in the safety of your craft then you’ve got nothing to gain by hiding. Too many chefs and cooks hide their funky projects in secret fridges or in the back corners of walk-ins. Instead, learn your shit and educate your health inspectors. If you can prove it won’t hurt anyone, then it won’t be illegal. You’re making food, not cooking crack – do it in the open.

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These are the results of fermented cabbage and fermented turnip performed at the public health lab in London. The tests were for all the major pathogens dangerous in food service, as well as a pH test. Both kinds of pickles tested negligible for any harmful bacteria, and registered a pH low enough to be considered shelf stable. The cabbage notably had a pH of 3.2 (remember, neutral is 7, the closer to 0 the more acidic a product is) on par or lower than the acidity of apple cider vinegar with no vinegar added – it only soured with bacteria.

Both of those samples were also taken because they had a formation of mold on the top (which mostly can be solved by using fermentation weights or boiled stones to keep the fermented product submerged below their brine) which under close observation proved to not affect the final product. If your ferment gets moldy, just skim the mold and a bit (like a centimeter) or the product below the mold out and get rid of it. Your food is still safe to consume. And while this sounds maybe more disturbing than mold, maggots swimming around on top of your ferment are also not terrible – maggots won’t burrow deeper than an inch, since they require oxygen to survive. I mean, you should use cheese-cloth or something to avoid getting maggots, but if you do just skim those bastards right into the garbage.

Botulism revisited

Eventually your ferment will become anaerobic, as the available oxygen will be used up by the bacterial respiration. And here it is, a crock sitting out of the refrigerator. Is that safe? Yes. The point of fermenting with LABs is that they make the food acidic or sour, and by the time the deeper part of the ferment is anaerobic they will have produced a safe amount of acid to prevent botulism poisoning at ambient temperatures.


Many different bacterial cultures, molds and yeasts are involved in fermentation. We’ve talked about the ones that produce acid as their biproduct, but other things are happening in the crock as well. As the food gets broken down on a molecular level different flavor compounds are produced. Naturally fermented foods tend to have a complex set of flavors that are impossible to replicate in other ways. The same way that sourdough bread varies from region to region, France to San Francisco having different kinds of wild yeasts living in them, different places and conditions are favorable to different microbes that aid in fermentation. For many kinds of ferments the temperature and humidity conditions are closely observed not just to ensure the success of the ferment but to coax a different flavor profile out of it.

It’s worth saying that Lao pickles and the signature fish sauce padaek are, well, smellier than other kinds of pickles. The German sauerkraut relies on the bacteria present on the cabbage to consume sugars in the cabbage to sour it, and while sauerkraut can become a fairy rich and complex tasting and smelling ferment it eventually equalizes when there stops being food for the bacteria to eat. The Lao pickled mustard greens som pak gaht have the addition of cooked rice water added to them; cultures present on the rice add to the flavor of the pickle as well as the starches (sugars) present in the water give the microbes additional food, reaching a next level of dank.

In fact, the addition of rice products is what gives the Lao repertoire of pickles such a distinctive taste. In padaek rice bran is mixed with the naturally released fish juice and allowed to age for at least a year. Meat fermentation is a bit different than vegetable fermentation because of what the source material is. It’s the same on principle, since a microbial culture causes the souring of meat to a safe pH, but its not the breakdown of sugars that cause the fermentation, but instead of proteins. Thai fish sauce, for example, doesn’t add the rice bran to the mixture, allowing the cultures naturally present on the fish to mature into a rich caramel sauce. Adding rice bran to the mixture adds cultures present on the rice bran, as well as more food for the bacteria to consume, adding a deeper, penetrating funk. In a fish sauce and funk music analogy, padaek is to other fish sauce as what George Clinton is to Earth, Wind & Fire – on way more LSD.

Cooked sticky rice is also added to som moo. Usually cooked rice held at ambient temperatures is a high risk zone for the pathogen bacillus cereus. Bacillus cereus is present on the rice grains themselves. The pathogen may survive cooking and then produce a shitty toxin in the rice that hurts your tummy. They can survive temperatures of up to 100C, or boiling temperature. I can’t find data that supports that sticky rice is a less frequent culprit of bacillus cereus than other kinds of rice, but I’d suggest it is because it is steamed at high temperatures – as steam can rich higher temperatures than boiling water. In any case, som moo often has an acidifying power added to it – and like botulism, bacillus cereus can be controlled with acid.

Now we’re all up to speed, so lets get to making some Lao pickles!


One thought on “Fermentation pt. 2

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