Sauerkraut is amazingly delicious and when eaten raw it's full of many species of probiotic bacteria! Sauerkraut is also full of prebiotic plant fiber, making it a gut health super food. Be sure to check out our Science of Fermentation blog, to gain a thorough understanding about the process of fermentation!
- One or two heads of cabbage (Savoy cabbage is what we used for this recipe)
- Cultured Guru Fermentation Salt
- 1 cutting board
- 1 well sharpened knife
- 1 large mixing bowl
- large glass jar(s)
- Fermentation weights
Brine Method: The brine method we use to make sauerkraut is to weigh your vegetables and add 2.5% of that weight in salt. Read the science behind getting your brine started here.We highly recommend just investing in a kitchen scale for about $10 from Target or Amazon. If you're going to master fermentation and select for the best bacteria in your ferments, you'll need one to weigh salt in grams. The scale we use in our home kitchen is this one.
- Remove the outermost leaves from the cabbage and lightly rinse it off. Don't remove too many leaves, just about the four outermost leaves. Next, chop the cabbage in to small pieces.
- Once the cabbage is all chopped up, place a large mixing bowl on your kitchen scale, set it to weigh in grams and tare off the weight of the bowl. Add the chopped cabbage to the bowl on the scale and record the weight of the produce.
- Multiply the weight of your cabbage in grams by 2.5% (example: if my cabbage and carrots weigh 2,270 grams.... 2,270 grams x 0.025 = 56.75 grams). This is the amount, in grams, of salt you will add to the chopped produce!
- Place a small separate bowl on your scale and tare it. weigh out your salt in grams.
- Add the salt to your mixing bowl of cabbage and thoroughly mix in with washed hands.
- You should be able to feel water being drawn out of the cabbage as you mix in the salt. This is the brine beginning to form! The longer you mix it in the bowl the better.
- Once you have mixed in the salt thoroughly, it is time to add the mixture into the jar. We use a one gallon glass jar, which is great for larger fermentation batches. Before you add in vegetable pieces, you need to dump all the liquid from the bowl into the jar. Then tightly pack in the vegetable pieces, removing air pockets and leaving room for a fermentation weight. You want the liquid brine to come above the vegetable matter when it's packed in the jar.
- Once the kraut is packed into the jar weigh everything down with fermentation weights. Put the lid on your jar, and place the jar at a moderate temperature away form direct sunlight.
- If there is not enough brine after tampering everything, you may add a small amount of 2.5% salt water solution to cover the cabbage (it MUST be a 2.5% solution). A 2.5% salt water solution is made by weighing one quart of water in grams, then multiplying the weight of the water by 0.025. The number you get is the amount of salt in grams you add to the water. This water can be saved in the refrigerator for multiple uses.
- During the first few days of fermentation carbon dioxide and bubbles will be produced. During this time you will need to burp the jar. To burp the jar, just remove the lid to let the gas out and check to make sure everything is still submerged below the brine. You must make sure that your fermentation weight and cabbage pieces are staying submerged BELOW the brine. You may have to press everything down with a clean spoon/tamper a few times.
- If you lose brine during the first few days (which is common in very full jars when bubbles are produced) see step #9 to make some salt solution to replace the lost brine. You can only replace lost brine in the first 1-4 days. Replacing it after the 4 days mark can dilute the acid starting to build up in the ferment, making it unsafe.
- The sauerkraut needs to ferment at least 3 1/2 weeks, so that all the stages of bacterial succession can occur. 3 1/2 weeks also allows enough time for the final stage Lactobacillus bacteria to produce enough lactic acid. Visit our Science of Fermentation blog to read more about the stages of fermentation!
We tracked our kraut throughout the fermentation process. By checking the progress of microbial stages under the microscope we have provided you with this handy timeline! If you follow our recipe and directions, your timeline of sauerkraut fermentation should approximately match ours!
24 - 48 hours: The brine should form, and all contents in the jar should be submerged beneath the brine. At this time there are still Gram negative bacteria and possible pathogens present.
48 - 72 hours: After 48 hours you should start to see lots of bubbles being produced. This is when the ferment enters stage two of vegetable fermentation. Leuconostoc bacteria begin to thrive and Gram negative organisms die off.
3 - 10 days: The bubbles in the brine will decrease, as the ferment leaves stage two and enters stage three. The ferment will become cloudy and start to develop a pleasant sour smell. Lactobacillus species are most abundant during this time period.
10 - 21 days: Lactobacillus make up majority or all of the microbial population. They produce copious amounts of lactic acid, and make the ferment smell even more pleasantly sour. This is the time in which the vegetable mixture becomes kraut and is preserved. This is when you want to smell and taste test.
21 - 28 days: Wait for the kraut to smell and taste as you like, and refrigerate when you find the smell and taste most pleasant! We like ours best when we refrigerate at about 25 days.
Peace, Love and Microbes,