Over the past few years, research has increasingly highlighted the importance of the gut micro-biome. The bacteria inside us, it appears, play a large role in everything from obesity to cancer, from creativity and intelligence to autism and depression.

At this point, gut bacteria research is still in its early days; there’s much more that we don’t yet know than we do. But, at very least, it’s clear that having healthy, diverse gut bacteria is broadly important in a healthy life.

As eating probiotic foods aligns well with ancestral health practices (one of the ‘check-sums’ we use in Composite’s approach – if generations of pre-industrial health wisdom aligns with new science, it’s usually a good sign), we regularly recommend our clients eat a variety of probiotic (and pre-biotic) foods.

But like with many healthy eating recommendations, adding probiotics to your diet can come at a premium. Because probiotic bacteria are only effective if they’re still alive when you ingest them, manufacturers have to carefully monitor production and control temperatures during distribution and display, which quickly jacks up prices.

The probiotic supplement VSL #3, for example, has been well studied, and clinically validated in treatment of conditions like IBS and ulcerative colitis. But taking VSL at the dosage used in most of those studies runs about $4000 a year, well beyond what most people can spend as just one piece of optimizing their health.

Fortunately, there’s an equally effective, and far less expensive, alternative: make sauerkraut at home.

An ounce of sauerkraut contains the same count of probiotic bacteria as clinical doses of VSL #3, and far more than what you’d find in less expensive store brands of probiotic capsules. A recent lab analysis of homemade sauerkraut concluded that one 16-ounce batch contained the same amount of probiotics as eight 100-capsule bottles of probiotics.

I realize that making sauerkraut at home is slightly intimidating. But it’s incredibly easy, and very safe. (The FDA recently declined to add regulations around sauerkraut, noting that there had been no recorded cases of illness caused by sauerkraut and similarly pickled foods.)

Here’s what you’ll need:

1. A big head of cabbage;
2. Some salt;
3. A food scale;
4. A knife;
5. A big bowl;
6. A quart jar, or a similar container to hold the kraut as it ferments.

And here’s what to do:

1. Slice the cabbage into thin strips.
2. Weigh the cabbage strips, then weigh out 1/50th as much salt. (e.g., if you have 500g of cabbage, you need 10g of salt.)
3. Put the cabbage and salt in the bowl, then knead it with your hands for about 10 minutes, until the cabbage starts to feel limp.
4. Press the salted cabbage down into the bottom of the jar.

Voila. That’s the whole thing. Now all you need to do is wait.

Leave the jar somewhere room-temperature (i.e., out of direct sunlight). Over the course of the first day or so, liquid will leach out of the cabbage, creating a brine. You want the cabbage to be completely submerged in that brine (as cabbage that peeks out can mold rather than ferment), so you might want to place something like a glass filled with water into the mouth of the jar as weight on top of the cabbage to keep it pushed down.

After about a week, taste the sauerkraut. It will still be pretty sharp-tasting, though it will continue mellowing (and becoming more-probiotic rich) over time. You can safely leave the sauerkraut pickling for well over a month, though I tend to find two to three weeks is about right for me. Once you hit a point you like, put the whole thing in the fridge, which will grind further fermentation to a halt.

You can use the kraut as a condiment, though it’s also pretty delicious eaten straight. (For some reason, this sounds intimidating to a lot of people, though most people will happily eat kosher pickles straight from the jar. Good news: this is exactly the same thing, with the same taste, just with cabbage rather than cucumber.)

Again, a forkful a day vastly exceeds the probiotic value of even a big handful of probiotic pills. And at just a couple of bucks a batch, you certainly can’t beat the price.