Sauerkraut is one of a delicious family of lacto-fermented pickles that include pickled cucumbers, kimchi, curtido. Most cuisines have their own lacto-fermented side dish, so I'll be using the word kraut as generic short-hand for the basic brine and fermentation technique that is used for all of these pickles.
Bonus: we'll be pickling them inside a sealed bag to make the entire process super-simple and stink-free. These are the same kinds of vacuum bags you use for sous vide, or for freezing food, so are easy to find.
In a hurry? Here's the basic recipe:
- chop and weigh vegetables
- add 2.5% salt by weight
- vacuum-bag, seal, and store in cool dark place for 4-6 weeks
- open and store in the fridge
Why eat sauerkraut and kimchi? And why make your own in a bag?
It's delicious, good for you, cheap, efficient, and amazingly low-effort.
- When beneficial bacteria pre-digest your food, they eat the things that can cause digestive upset and create or liberate all sorts of nutrients, making krauts a great source of vitamins B, C, and K. Homemade kraut is also full of probiotics, unlike store-bought kraut which is usually pasteurized (which kills the good bacteria) for shelf-stability.
- Kraut is a great way to use up leftover vegetables from your garden or CSA, or simply to clean out your fridge of overly-optimistic purchases.
- Kraut stores beautifully, so is a great way to prepare for a long ocean voyage (no scurvy!), or a post-apocalyptic future.
- It's FAST! It mostly depends on how fast you chop: the salting and bagging takes about 2 minutes per bag.
- It doesn't smell when made this way! If you've heard stories about burying kimchi jars in the back yard, fear not - the bag contains any fermentation odors, so you can safely store these in your house.
- This method selects for bacteria (mostly lactobacilli) that can live in a high-salt, acidic environment without oxygen or light. These are the good "probiotic" bacteria mentioned above: it's a hostile environment for yeasts and toxic bacteria, so you get flavorful crispy kraut every time.
Step 1: Tools and Ingredients
- cutting board
- sharp knife
- peeler (optional)
- vacuum sealer and bags
- I have a fancy chamber vac, but a FoodSaver is just fine. Ask around, you can probably find a friend who got one and hasn't used it. CraigsList is also a good source for unloved FoodSavers, if a new one is outside your budget. Try one to see if you'll use it enough.
- Scale (that measures in grams)
Ingredients:pick a tasty-sounding combination of hard veggies, greens, and herbs. Mix and match to your taste.
- salt (NON-iodized, as iodine can kill your bacteria. That means Kosher or sea salt is fine.)
- cabbage (purple, red, napa, savoy, Brussels sprouts)
- bok choy
- dried fish powder, tiny dried shrimps, or liquid fish sauce
- fennel bulbs
- dried spices (fennel seeds, caraway seeds, red pepper flakes, etc) in moderation
- garlic in moderation
- ginger (use in moderation, or it can kill your bacteria)
- kale (any type)
- scallions/green onions
- fresh herbs (basil, mint, thyme, oregano, tarragon, etc) in moderation
- caulflower (any color)
- radishes (daikon, red, black, watermelon)
- beets (use in moderation - they're full of sugar and the bacteria get excited)
- winter squash (use in moderation first time - some types can get the bacteria excited)
- other leaves, hard vegetables, etc that you want to try! Use in moderation the first time to see how they behave, then go nuts.
Step 2: Select Your Vegetables
What vegetables do you want to use? I recommend starting with a basic set, perhaps matching a sauerkraut or kimchi you've eaten before and liked, then start experimenting. Note that "chop all the things and throw them together" is a perfectly viable recipe.
Here are some of my favorites to get you started:
- 1 medium head green cabbage, cut to bite-size ribbons
- 1 small bunch dinosaur (lacinato) kale, cut to thin ribbons
- 2 onions, quartered and cut in thin slices
- 1 medium bulb fennel, chopped to thin coins & slices
- 4 carrots, chopped to thin coins or small chunks
- fennel seed
- 2.5% salt by weight
- 1 medium head napa cabbage, cut to coarse chunks
- 2 medium onions, quartered and cut in slices
- 1 bunch green onions, chopped
- 4 carrots, chopped to thin coins or small chunks
- 1cm cube ginger, finely chopped or grated
- 3-6 cloves garlic, finely sliced or minced
- 1 tablespoon chopped seaweed of your choice (optional)
- 1/4-1/2 teaspoon dried fish powder, dried tiny shrimps, or fish sauce (optional, but tasty)
- korean spicy red pepper flakes to taste
- 2.5% salt by weight
Step 3: Chop Your Vegetables
Think about your favorite types of sauerkraut or kimchi - chop your veggies to match. You may also want to change size/shape to match the food you plan to eat them with.
It's basically impossible to do this wrong. You can cut into large chunks, small chunks, long thin ribbons, or tiny mince - you can also shred things in the food processor, slice them on a mandoline, or use any other technique to make them bite-size and increase their surface area.
The more exposed surface area, the faster and more efficiently your bacteria will work. Big chunks will take longer to ferment all the way through, so especially for harder veggies like carrots it's best to cut them into smaller, bite-size chunks.
Step 4: Combine and Bag
Toss your chopped veggies together, and scoop into your vacuum bags.
Turn down the top of your bag about 1.5-2" to keep the sealing surface clean, and only fill the bags to halfway so there's plenty of room for your bacteria to outgas and expand the bag as they ferment your veggies.
NOTE: if you are using large amounts of dried herbs/spices, say for making spicy kimchi, add these AFTER you weigh your veggies and add the salt. A sprinkle of fennel seeds isn't a big deal, but you could add them after-salt as well.
Step 5: Weigh and Add Salt
Weigh your bag, subtract the weight of the bag, and calculate the amount of salt you should add. We want 2.5% salt, so multiply the weight of your veggies by 0.025.
- Example 1: 113g (bag+veg) - 13g (bag) = 100g (veg) x 0.025 = 2.5g salt
- Example 2: 513g (bag+veg) - 13g (bag) = 500g (veg) x 0.025 = 12.5g salt
Weigh out your salt, and dump in bag. This is a great job for kids working on their basic math skills.
NOTE: if you're adding lots of dried spices, do it now after the weighing and salting.
Step 6: Seal Your Bags
Do this immediately after salting if you're using a FoodSaver, as you want to suck out the air while the bag is still dry. If you wait too long, the salt will start pulling water out of your veggies, and the liquid can cause problems with the FoodSaver. A chamber vac like the one above can handle liquids without issue, so no rush to bagging.
Flip the bag edge up, and seal according to the bag-sealer's instructions.
- If you're processing lots of veggies, get a bagging assistant! One of you can weigh and salt, the other can seal. It's a great job for kids who can't quite handle the salt math.
- Shake your salt around to distribute before bagging, as this will get things started faster. If you forget, not a big deal - as the veggies drop water, the salt will dissolve and self-distribute.
- Double-check that you've added your salt and dried spices before bagging!
Step 7: Store 4-6 Weeks, Checking Periodically
Store your kraut bags in a cool, dark place for 4-6 weeks. This helps select for the type of bacteria you want to grow, and keeps them from growing too fast.
The optimal temperature is about 60F, so if you have a basement this is the best bet. If not, check temperatures in your house or apartment, and stick them in a cabinet or box in the coolest area. If you live somewhere hot, you could bury a box or bucket in the ground in a shaded area and cover the top with dirt for insulation, or hook up a mini-fridge to maintain proper temperature.
Check on them periodically if you can to make sure everything is going well. Massage the bags or shake them around to redistribute your bacteria and their food sources for fast and even fermentation. See pictures 2 and 3 for before and after fermentation photos - the bags will inflate differently depending on the vegetables used, the fermentation temperature, and how long you've left them to ferment. Note that some batches won't inflate much at all - this is also fine, it just means your bacteria weren't particularly gassy.
Step 8: DANGER: OVERINFLATION
Beware! Some vegetables make your bacteria very happy (and gassy) because they're full of sugars. If you work with these vegetables, keep a close eye on their progress and open them before they're in danger of popping the bag and creating a giant stinky mess. You can also leave extra headspace with these vegetables for an extra margin of safety.
Here's a list of vegetables that have caused me problems - your mileage may vary with local varietals, temperature, and luck. Note that they still make delicious kraut, just require additional attention to avoid an unexpected explosion.
Things to watch out for:
- beets (we make sugar from these! they're also delicious kraut)
- cauliflower (my kids adore fermented purple cauliflower)
- some winter squashes
- any fruits (I generally avoid these entirely)
Step 9: Jar and Store
When you're finished fermenting your sauerkraut or kimchi, move it to the refrigerator. This will slow (but not entirely stop!) the bacterial fermentation.
I transfer mine to jars and store on the bottom shelf of the fridge. We go through kraut super-fast, as the kids love it - it's a great way to encourage them to eat their veggies. We serve kraut on eggs, pork, chicken, sausages, and any other greasy protein - it's also great with rice, and as a tangy side with any spicy food.
You can just toss the bags in the refrigerator to ensure they don't get more flavorful than you prefer. Note that there's nothing wrong with continuing to ferment your kraut, short of popping the bag and creating a mess - this was a method of long-term storage before we had refrigerators. However, most people have a preferred level of fermented taste, so use your refrigerator to maintain your preferred taste profile.
These will keep indefinitely in the refrigerator, so with a bit of pre-planning you can be fully stocked with delicious, healthy sauerkraut all year long.