It wasn't until a few years ago that I learned about fermentation. I had thought the only way to preserve food was pickling using an acidic solution. I had no idea that nature could create its own way of preserving certain foods simply using salt and time. And if that wasn't amazing enough, it also creates an incredible probiotic in the process to improve your gut health.
My favorite routine thing to ferment is cabbage which converts into sauerkraut. It's literally just two ingredients - shredded cabbage and kosher salt. That's it! Jars of sauerkraut in the grocery store can sell for $6-9. One jar only uses one pound of cabbage, and one pound of organic cabbage is usually only $0.99-$1.50 at most. So making it yourself saves a substantial amount of money.
The trick to my recipe is math. When you ferment, you want to target 2.5% salt ratio to all other ingredients. This ensures enough salt for nature to do its thing with preservation. This means you'll need a scale and ideally a scale that measure in grams for precision.
The other trick is to make sure all ingredients are submerged in a brine (filtered water and salt equaling 2.5% of the water). To do this, you need a vessel and weights. For the vessel, you ideally want glass or ceramic, no metal or plastic. My go-to is a quart size, wide mouth mason jar.
For the weights, you want something that can cover the entire surface area so nothing floats to the top of the brine. You can buy weights specially for this. If you use a glass or ceramic bowl, you can put a plate on top. My go-to with the jars are river rocks that I had in my backyard that I wash and store in my kitchen.
A few other tips, I prefer green cabbage over red cabbage because the color pigment in red cabbage can stain things particularly in this process because of how wet and soggy it gets. For the filtered water, make sure there is no chlorine by either using bottled spring water or allowing home filtered water to sit out uncovered for 24 hours for the chlorine to evaporate. Otherwise this chlorine could kill the good bacteria in the cabbage that is needed to create the fermentation. For the salt, I like kosher salt since I have that in my kitchen. Sea salt also works. Iodized table salt does not because iodine can also kill the good bacteria.
Lastly the recipe below is for one pound of cabbage since that fits well in a one quart mason jar. But you can scale this easily by weighing the amount of cabbage (after shredding it to account for waste) and then multiply the weight by 2.5% to determine the amount of salt.
Now with those tips, follow this super easy recipe to create your own homemade sauerkraut.
- 1 pound of cabbage (about half of a large head of cabbage) - this is 454 grams
- 12 grams of kosher salt - 2.5% of the 454 grams of cabbage is 11.35 so I rounded up
- 120 grams/mL of filtered water (no chlorine) + 3 grams kosher salt. This is the brine solution for topping up the water level at the end.
- Grab a large mixing bowl (note this can be metal or plastic since this won't be used for fermenting).
- Shred the cabbage by quartering it, remove the core and then slice the wedges from top to bottom in thin strips.
- Weigh the cabbage and multiply that weight by 2.5% to determine the amount of kosher salt to add.
- Add the salt and mix into the cabbage. Allow the salt and cabbage to sit for 15-30 minutes to draw out some of the water and soften the cabbage making it easier to put in the jar.
- Add the cabbage and salt to the jar once scoop/handful at a time. Be sure to pack down the cabbage to the bottom of the jar as you go. And don't be afraid to be aggressive. I punch it down using my knuckles.
- If there is any water in the bowl, be sure to add that to the jar as well.
- Add the weights to the top of the cabbage and be sure the weights are below the lid line of the jar.
- Now look for the water line. If it is already above the top of the cabbage then you are done. If it isn't, add the brine solution until the water level is 1/4-1/2 inch above the cabbage.
- Do not overfill the jar with water. You'll want to keep 1 inch of space between the water level and the top of the jar. This is because fermenting creates air and bubbles that will cause the water level to rise.
- Top the jar with the lid and attach loosely because you want the bubbles and gas to escape as it ferments. If you attach it too tight, this could cause the jar to crack creating a mess and a hazard. For safety, I like to totally unscrew the lid on a daily basis just to be sure the gas is released, and I sit the jar in a bowl to catch any overflow solution.
- Now just let nature do its thing. The minimum time is typically 4 days but you can go up to 7 days. On day 2-3, you'll start to notice those bubbles. If you don't, then something is wrong. You either didn't use enough salt or something in your process had chlorine or iodine to kill the good bacteria.
- Also, if you ever see any mold form, this is not good and the solution should be thrown out. This is probably because the cabbage was not fully submerged in the brine solution. A few stray cabbage pieces floating on top are fine but ideally you want all of it submerged.
- When to stop fermenting depends on your preference on the amount of sourness. Day 4 is more mild. Day 7 is more sour.
- Once it is complete to your liking, remove the weights and give it a stir. You can now tighten the lid and store in the fridge. The cooler fridge temperature will slow down the fermentation, but gas may still build up. So be sure to use or open at least once a week to release the gas.
- The sauerkraut can keep for 30 days or so in the fridge and potentially longer as long as the cabbage is submerged but this requires keeping the weights in. Mine usually only last 1-2 weeks so I don't need to keep weights on it. I just make sure all the cabbage is mixed into the solution (nothing stuck to the sides of the jar) before I put it back in the fridge.