Here’s an easy way to add both probiotics and prebiotics to your life: Fermented raw potatoes. The mildly tangy flavor of these fermented raw potatoes go well tossed into a salad, though you can just eat them right out of the jar, too.
Because they are raw, there are zero net carbs but plenty of fiber. (When heated, however, fibers depolymerize or break down into sugars. When raw and unheated, fibers remain in polymer form.) Raw potatoes therefore provide you with prebiotic fibers to nourish bowel flora.
When you lactate-ferment these raw potatoes, you also cultivate beneficial bacterial species such as Lactobacillus, Bifidobacteria, Leuconostoc species and others that add to healthy bowel flora.
Fermented raw potatoes are therefore an easy and convenient way to add both more probiotic species and prebiotic fibers. I found potatoes to be easier to ferment than most other veggies, as the potatoes, chopped into half-inch (one centimeter) cubes, sunk to the bottom of the jar, thereby not requiring any device to weigh them down to keep them below the air-water interface. (Recall that lactic acid fermentation is an anaerobic process and is inhibited by the presence of oxygen. Veggies must therefore be kept below the air-water interface. The dense cubes of potatoes accomplished this all on their own.)
The recipe is very simple, but there are some reminders to make sure that fermentation can proceed. First, use filtered or distilled water, as tap water that contains chlorine or fluoride will block fermentation. Likewise, when making the brine solution, do not use iodized salt, as iodine will block fermentation, also. (I have used sea salt many times with success.)
To make fermented raw potatoes, place approximately 4 cups of filtered water into a jar, followed by enough salt to generate the level of saltiness you desire (e.g., 1 tablespoon).
Chop potatoes (unpeeled; if any green tinge is present on the skin, remove) into half-inch cubes, then add to water. Cover with paper towel, cheesecloth, or other non-air-tight device.
You will see the water turn cloudy over the next 48 hours, along with tiny bubbles, all reflecting the process of fermentation. If any white film appears on top, remove with a spoon and discard. When the water is moderately cloudy and potatoes have that lactic acid “zing,” transfer jar to refrigerator. Consume within the next week.
Couple of questions.
1. How many should be consumed in a day
2. Is there a good/bad time of day to consume them
3. should they be eaten with/before or after a meal.
Love the idea of them sinking to the bottom as I tried using marbles tied in cheesecloth to sink vegetables below the water line with only some success.
Laurent wrote: «Couple of questions.»
More than a couple answers.
re: «1. How many should be consumed in a day»
That question could be about prebiotic fiber or probiotic organisms.
On prebiotic fiber, program guidance is to work up to 20 grams/day, mixed and varied. If someone encounters a reaction when adding prebiotic, that’s suggestive of a dysbiosis that needs separate investigation.
More than 20g/day doesn’t seem to be a problem, if adapted to it. Extant hunter-gatherer cultures are getting over 100 (but have radically different gut flora). I probably get 40-50 grams/day, due to the amount of green banana in the morning smoothie.
On the probiotics, with fermented foods you are likely to hit a prebiotic limit before you hit a probiotic limit.
re: «2. Is there a good/bad time of day to consume them
3. should they be eaten with/before or after a meal.»
Some sources suggest that for maximum likelihood of probiotics making it to the lower intestine intact, take prior to the meal, perhaps prior to the first meal of the day. I don’t recall any specific WB/Undoctored program advice on timing, so it may not be that big a deal.
re: «…tried using marbles tied in cheesecloth to sink vegetables below the water line with only some success.»
Circular glass weights are available specifically for this application. If you happen to have just the right bottle and barware, a tall glass full of water can also be used to push down the veggies.
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Why are we using a non airtight container everything else I ferment I closed the lid and burp it daily or use a vacuum bubble
Hello…how many potatoes should be used per 4 cups of water and are there other veggies that would work with this concept? Thank you..
Carol J StJohn wrote: «…how many potatoes should be used per 4 cups of water…»
I doubt that question really has a generalized answer, due to the variation in potato sizes. With the water in the jar, cutting up potatoes one at a time, and adding them until within an inch of the surface, would closely match what’s depicted above.
re: «…are there other veggies that would work with this concept?»
If by “this concept”, we agree that the resulting fermented product provides both a generous amount of prebiotic fiber, and a typical-for-fermented-food amount of probiotic cultures, then the list of candidate veggies might be fairly short. Many veggies just don’t represent that much prebiotic. I have a list here.
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Good to know for the future. Thanks for the post. We WB followers like some “strange” foods, don’t we? I now eat things that I would have formerly completely turned away from on a standard, higher carb diet. Things like ginger, turmeric, cloves and bitter vegetables. I’ll actually brew a cup of ginger and turmeric tea once in a while. It has an amazing relaxation effect. I remember Dr. Davis saying that his patient’s taste buds completely transform on WB a while back in a video. People seem to enjoy and want to cook up a bunch of non-starchy vegetables. I guess I’m not the only one here.
Of course! Brilliant! Ferment a vegetable that not only carries its own prebiotics but its own probiotics within.
I read the post, got up, and made a batch. The taters are soaking in salt water as I write.
Is it alright to peel the potatoes?
Mike from Wisconsin wrote: «Is it alright to peel the potatoes?»
It doesn’t appear so. Although not specifically addressed in the recipe above, let’s consider the question: where do the fermenting microbes come from?
Based on the fact that the photo shows cubes with skin, my presumption would be that they are the source.
If you want to use peeled potato, you’ll probably need to specifically add fermentation cultures (and I have no detailed advice on that).
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Very interesting! Glad I found this post and your website! I just made a small batch to see how it will turn out, sadly I’ve seem to overdone it with the salt – had a small taste right after putting everything together, it’s really salty – do you think if it’s much too salty for me, it’s too salty in general?
Tanja wrote: «…sadly I’ve seem to overdone it with the salt…»
How much did you use (vs. how much water)?
The recipe above was 1 tablespoon of salt and 1 quart of water, but evidently allowing for variation: “…enough salt to generate the level of saltiness you desire…”
re: «Glad I found this post and your website!»
That suggests that you might not be familiar with the wider Undoctored (and Wheat Belly) programs, which have a lot to say above major topics in diet; one of which is salt. People following consensus low-salt advice are not getting enough salt.
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I had to google what a quart relates to in the metric system (roughly one litre), and I’m afraid I used a teaspoon for a much smaller amount of water, roughly around 150ml. So that’s like 6 – 7 times the recommended amount :(
Oh today is absolutely not my reading day. You said tablespoon. I used a teaspoon. Anyway still a lot! It’s way beyond my preferred level of saltiness. I wonder if I should leave it like it is to see if it could still work, or rather either take out some water and replace it with unsalted water, or pour the whole thing into a bigger container and dilute it there. Will a jar with too salty brine eventually spoil, or just sit there like forever?
I’ve never really liked fermented foods, so I thought I’d start with potatoes because I love potatoes. I’ve had one potato cut up into 1/4 inch chunks fermenting for 3 days now. I have two questions.
1. Is that long enough to ferment it to get good probiotics?
2. How much of that potato do I need to eat at a time to get good benefits?
Thanks!
Adam wrote: «I’ve had one potato cut up into 1/4 inch chunks fermenting for 3 days now.»
How is it doing as regard the criteria in the final paragraph of the instructions above?
re: «How much of that potato do I need to eat at a time to get good benefits?»
Do date, what has been you daily intake of prebiotic fiber sources (in grams)?
If you haven’t been doing anything in particular, you might want to start with about 5 grams of the fermented potato (as most of that weight is raw potato, which is nearly 100% prebiotic fiber). Program guidance is to work up to 20g/day of mixed and varied sources, which suggests no more than 20g of this recipe on any given day.
The other aspect of this is the probiotics (the microbiota doing the fermentation). Fermented foods tend to amount to a topping-off, so at and below 20 grams/day of this potato, you’re probably not likely to overdo the probiotic benefit.
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