Hacker News new | past | comments | ask | show | jobs | submit login
Fermented foods probably deserve their healthful reputation (sciencebasedmedicine.org)
135 points by tokenadult on Nov 7, 2015 | hide | past | web | favorite | 49 comments



Two additions to the probably positive effects on health:

1. The author rightfully mentions it, but I'll repeat it nevertheless because fermented foods are often only characterized as "healthy" without any mention for their taste properties: it can simply be delicious. I stopped drinking soda in favor for water kefir [1], and I'm not missing Coke/Fanta/... It takes me 10 minutes to brew every two days and it's yummy.

2. When you make it, you know what's in it. My homebrew kefir is just water, sugar, figs, lemon, sometimes ginger, sometimes maple syrup (and kefir, of course). No concern for unknown colorants/conservatives/additives.

[1] http://nourishedkitchen.com/water-kefir/


I'm so glad you mentioned kefir! Lots of people have no idea what it is. My roommate in college used to make it all the time - every morning he'd have more kefir, and for maybe 2 minutes of work a day.

Yogurt is also extremely easy to make - just put a spoonful of yogurt in a smallish container of milk, and wait. It's also pretty easy to add things to, just like kefir. Fresh yogurt often tastes way better than storebought, and you know the bacteria are active!


Don't you have to heat it, though? I vaguely remember making yogurt once and I thought I had to keep it at just over 100F for hours on end.


I submerge my soon-to-be-yoghurt jars in 42°C hot water in a pot, then put that next to the radiator during the winter months, or in the sun during the summer months. Check up on the temperature maybe once or twice over the course of 6-8, then put in the fridge overnight.

I usually make 1.5kg of yoghurt that way, and it keeps for about one to two weeks — but it never survives that long (2-person household), so I make yoghurt around every three days. We use it for breakfast cereals, yoghurt with jam (home made jam for added benefit :-) and ayran. It's fantastic!


Didn't know about ayran, will try it, thanks :) . Do you prepare it just with by "mixing yogurt with iced water", or do you add flavor to it? (like Indians do with lassi [1]).

[1] https://en.wikipedia.org/wiki/Lassi


I do like lassi, from time to time (as long as it is without "black salt," which I consider an acquired taste that I probably won't acquire anymore) but I mostly drink ayran.

It is best prepared with just a couple of tablespoons of yoghurt (3-4) in a liter-sized bottle of water, with a teaspoon of (ordinary, white) salt added to it. Shake well, enjoy :-)


For safety, you should keep yogurt warm as it can be out-competed by harmful things, I once tried using something like this: http://smile.amazon.com/TAYAMA-YX-45A-Tayama-Vacuum-Pot/dp/B...

But I found it difficult to get a thermal pot down to the right temperature range to begin yogurt and switched to making only kefir. Kefir is less likely to lose to a contaminant at room temperature as it is a diverse cocktail.


In my experience, the easiest method is to wrap a heated blanket around a pot.


I make yogurt by heating the milk to 190F, holding it there for a minute or two, then taking it off the heat. The 190F helps break down the proteins (casein if I remember correctly) to help the yogurt setup. If your milk hasn't been pasteurized, this also pasteurizes.

I let the milk cool naturally to 115F, then I mix a tablespoonful of the warm milk with two tablespoons of my starter yogurt (for a gallon of milk). I continue to mix a tablespoon of milk into the starter until the starter is pourable. It then gets added to the pot of milk and stirred. If I'm making skyr, the rennet goes in at this stage.

The pot is usually at 112F-114F and get wrapped in towels and thrown into a warm oven, I usually heat the oven to it's lowest setting (200F) while the milk is warming, then turn the oven off while the milk is cooling. The milk sits in the oven overnight. The 105F-115F range is the "ideal" temperature for the bacteria.

In the morning, the curds get sliced, strained, and jarred.

Once you get used to it, making yogurt once a week takes an active 30 minutes of my time.


Do you have details/a link to what exactly goes into making skyr?


I don't have any links. The method I was taught is pretty well outlined in my comment above. Instead of yogurt being mixed in, skyr (Siggi's is what I use since it's what I can get a hold of) is mixed in. Additionally when the skyr is added to the milk, 1/2 of a rennet tablet is added.

I believe that traditional skyr is made from bacteria in baby goat stomachs; the rennet is substituting this. Additionally, skyr is usually pretty thick, so I strain the curds until I get softened cream cheese consistency.


If you use a mesophilic (rather than thermophilic) strain you don't have to keep it warm: it ferments at room temperature. The most popular strains in the US are all thermophilic, but Finnish viili and a bunch of other (primarily Scandinavian) strains are mesophilic and you can just plop it on your counter overnight. "Bad" bacteria won't have a chance as long as you started with clean materials.


One question, what about the sugar that doesn't get fermented? Two percent doesn't seems like an insignificant amount, although maybe I've been somewhat unfair, if we compare them with sodas or a candy.


You can wait until bacteria and yeasts eat up all the sugar, or leave residual sugar in there. The problem is, without residual sugar you will get a vinegar-y taste.

I switched to milk kefir for that reason - I don't want to drink sugar every day, as my SIBO returns quite quickly if I do.


Not sure I'm getting your question; yes it's up to you to decide the quantity of sugar you like.


There is always residual sugar, which doesn't get fermented no matter how long you leave it. If you really want to avoid all sugar, then you just have to avoid these drinks. I don't think there's a way around it.


Yeah. See also manmal's answer, which covers something important if you do want to absolutely avoid sugar: you have to leave it ferment for a longer time, and it gets vinegar-y.


Speaking of fermentation, I recommend that anyone who enjoys bread has a a sourdough starter. It's one of those things where a tiny investment of time (a few minutes per day, or less if you're storing an already-started starter in the fridge) makes for a large payoff of great-tasting bread.

This is probably the simplest and easiest guide I've found, and it's the one I've used to greatest success: http://slice.seriouseats.com/archives/2010/11/how-to-make-so...


Where I live it's named an `Herman' cake or bread. You are supposed to cut it into four parts and distribute three of it to friends or strangers and restart the thing with the remaining part. It's kinda fun. Kids love it :).


That's a neat concept! I might do something like that among my family this year -- I've been looking for a fun, frugal/minimalist approach to Christmas gifts.


I've found the rise time of starters to be too unpredictable. These days I make my bread with a small (1/2 tsp or so) amount of yeast, but let the sponge grow overnight. Results in very tasty bread that rises on my schedule.


One thing that I missed the most after coming to US was sourdough bread. I couldn't stand this sweet, sponge-like "bread" that was available here. I didn't have to use fermentation starter in Poland, because there you can get all kinds of fermented foods straight from the store. The explosion of taste I had after I tried my own-made sour bread is beyond means of expression available to human race.

If someone in bay area would like to try baking their own bread, but they don't want to grow the fermentation starter from scratch, let me know, I can share mine. it's based on whole-grain flour, and it's pretty stable (6 months old now!).


Fermentation is indeed one of the most traditional and simple ways of preserving food, and has been practiced since millenia by almost all traditional and modern societies. There is also some scientific evidence that fermented foods are good for your health.

Unlike what most people think it is also very safe and easy to do at home. Making sauerkraut or Kimchi is a fun experience and the result can usually compete with most of the produce you can find in supermarkets.

If you're interested in home fermentation make sure to check out Sandor Katz's "The Art of Fermentation", which is a great reference:

https://www.google.de/search?q=sandor+katz&oq=sandor+katz&aq...


Looking at dietary benefits is very complex. For example, there is one study that suggests there are no known benefits to yogurt. http://www.medicalnewstoday.com/articles/292809.php

The point is that when I see numbers of test subjects, duration, measures of benefit, etc I feel more confident that some thought has gone into understanding benefits. However, Unless a test subjects only ate that one product or all test subject diets were controlled, it's difficult to measure benefits.

After reading this article, I was unsure of how rigorous this research was. Despite many references, the strength of the data wasn't analysed in a way that was quantifiable. This article isn't alone. One of the few miracle vitamins (vitamin c) also has its critics when it comes to potential benefits.

In summary, I wasn't convinced one way or another by this research.


> Looking at dietary benefits is very complex. For example, there is one study that suggests there are no known benefits to yogurt.

Well, apart from its being food, protein and fat. :)

I once spent part of an evening reading the labels of all yogurts in my local chain supermarket, looking for the smallest counts of "ingredients that aren't yogurt" and carbs (I'm type 2 diabetic, hence my interest in carb count over the day). For my supermarket, that turned out to be Fage greek yogurt. I eat their full-fat product almost every morning, and I can state without a doubt that it is food. :)


Naturi yogurt has even lower sugar. (But looking at their website, they don't seem to be available nationwide -- east coast only)


That study that the news article links to is pretty weak: there is no control and they only did a single baseline assessment of yoghurt consumption. Whereas some of the articles on outcomes referenced in the article are review articles.

But my main takeaway from this was not so much about outcomes (I would need to look into those studies more closely as you suggest). Rather it is that studies show that fermented foods are capable of surviving digestion and altering gut flora.

Overall I am really happy to see an article based on research citations rather than that it was published in NYT.


Vitamin C is easy: there are no benefits, assuming you've already reached the amount you need.


OK, so we had this big news fit over how cured meats are bad because something something nitrosamines something colorectal cancer.

As far as I am aware, the same compounds are present in e.g. vinegar-pickled cucumbers and can lead to esophageal cancers. That appears completely lacking from the discussion in this article, though perhaps the purely-bacterially-fermented vegetables result in different compounds.

Does anyone have any recent information about the relative risks of the nitrosamines present in pickled vegetables vs e.g. bacon? If bacon is in the hazard category of "causes cancer", aren't also pickled vegetables?


Surprised they don't mention wine, beer and chocolate (and to a lesser extent, tobacco) which also involve fermentation.


Don't be. The point is something that contains active "probiotics" and not something that is fermented before being sterilized or roasted before consumption (you also missed coffee in your list).


Beer, wine and tobacco, at least, aren't necessarily sterilised before consumption. Source: I brew, make wine and smoke tobacco:-)


Tobacco has a healthful reputation? Where?


> Tobacco has a healthful reputation? Where?

Nothing serves life and soundness of body so well, nor is so necessary as the smoke of the royal plant, tobacco. —Dr. Cornelius Bontekoe, 1685

Man, the creature who knows he must die, who has dreams larger than his destiny, who is forever working a confidence trick on himself, needs an ally. Mine has been tobacco. —John Boynton Priestley

[Tobacco] is the passion of honest men and he who lives without tobacco is not worthy of living. —Moliere


>Man, the creature who knows he must die, who has dreams larger than his destiny, who is forever working a confidence trick on himself, needs an ally. Mine has been tobacco. —John Boynton

That's an incredible quote. Thanks.


Is fermentation invlved in this?: https://en.wikipedia.org/wiki/Perpetual_stew


It is not clear from the article or its online references. I suspect that it is not fermentation. It sounds like the stew is kept at a simmer. Extra water is added to prevent burnt food and is sterilized for drinking. New ingredients are added whenever they are ready and allowed to stew for hours before eating. Assuming that my understanding is correct this is the exact opposite fermentation, keeping the stew hot will kill all but the most hardy bacteria.


Almost certainly not, since the stew is simmering frequently.

Back when I worked from home, I kept a pot of stew going for months. It was pretty nice: depending on the ingredients I added, I could get a French, an English, a German, a Mexican or an Indian flavour, and when I wanted to be lazy I could just let it go down a bit further than usual.


I really don't think so. Fermentation is something that happens at room temperature and warming a stew (even as much as 40°C) would kill all the yeasts.

Also, fermentation would render the stew sour, which I don't think is a good quality for a stew.

I think that the idea of the perpetual stew is the contrary: to keep the stew always boiling on the fire in order to prevent the microorganisms from growing and spoiling it.


I've recently starting trying my hand at brewing kombucha after trying some. The first batch was terrible, left it too long in the first fermentation stage. Will be bottling the next batch for secondary fermentation today, so hoping it will come out betterer.

I'm wondering if water kefir might be easier and how it compares to drink.


Milk-based kefir (I have no experience with water-based kefir cultures, but imagine they'd be similar) is fun to make. The grains are easy to handle. It's similar to kombucha in difficulty, but grows faster, and you make smaller batches generally. Like kombucha, it can get quite sour if you leave it too long. I stopped drinking milk so I no longer make it, but remember enjoying the process. I have a Flickr album showing the process here: https://www.flickr.com/photos/davidniergarth/albums/72157604...


I don't think water kefir is similar to kombucha in difficulty, kombucha seems much more fragile. I killed my kombucha mother at the first batch (not sure what went wrong), and never got any problem with water kefir. A friend who tried both reports the same experience.


I've done both. I found kombucha really easy to maintain. My biggest problem was getting over-ambitious and moving from a one-gallon glass container to a two-gallon container. The larger container made too much and got to be a hassle to process; it got to be a burden. I wish I had kept that smaller container.


One thing to be aware of is that many commercially available fermented foods (especially vegetables) have undergone pasteurization, which kills the beneficial bacteria. I've found that the refrigerated section of my local Whole Foods is the best source of unpasteurized kimchi, sauerkraut, and pickles. (Also check out the vinegar section, where you can usually find unpasteurized apple cider vinegar.) Look for the words "probiotic" or "unpasteurized" on the label; if a product doesn't have either of those words, chances are it contains no active cultures.


I'm still amazed at how the marketers are only starting to realize the health benefits of fermentation. 'Actimel' for example is a yogurt drink they sell in my parts, and the ADs for it always overplay the importance of it, as if probiotics are some life giving elixir.

What they overlook is that probiotics are indeed that: 'pro' in that they prevent rather than treat. Do I eat yogurt because I like it? Probably not, but I feel wonderful 2-3 hours after eating it, and can almost feel the PH in my gut getting more balanced.


Kimchi is also an awesome and inexpensive snack. I always have a big jar of it (from the grocery store) in the fridge to snack on when I'm too lazy to cook.


As an aside, this is the first time I've been to that website, and it's really good. We need more of this.


What a refreshing skeptical assertion. Is this typically the standard among health science journalists?


Sadly, no, but the author is also not a journalist. From her attribution at the bottom: "Lucy Shewell, PhD, is a research scientist in the field of molecular microbiology."

Science Based Medicine was also founded by scientific skeptics, so "refreshing skeptical assertions" will be the norm there.




Registration is open for Startup School 2019. Classes start July 22nd.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact

Search: