The crock I used is a European style fermenting crock. There are other methods found on You tube which can be used. I only have experience with the European style crock with water seal lid.
The crock can be found online on Amazon and through this link:
Basic Sauerkraut for 5liter crock
5 lbs shredded cabbage, removed larger outer leaves and set aside.
3 tablespoons sea salt
a mixture equivalent to 2 teaspoons of
1 tablespoon juniper berries or whole peppercorns
4 oz. buttermilk
Toss the shredded cabbage, salt and seasonings together in a large bowl. Add to the crock. Using very clean hands , a potato masher or sauerkraut stomper, which I recommend: stomp and smash down the cabbage mixture , packing tight in the crock. Leave at least 1/5 head space in crock as the carbon dioxide produced in the fermentation process needs room .
Continue to stomp cabbage mixture until juices are released . Ideally you want enough juices from cabbage to cover the top of the packed mixture.
Make sure mixture is firmly packed.
Once the mixture has produced all the liquid it can, add the buttermilk. Sometimes the cabbage does not create enough juice. In that case make a brine of salt water the strength of sea water, boil it allow to cool before adding to cabbage mixture.
Place the reserved large cabbage leaves that were removed prior to shredding over the top of the cabbage mixture. Put the weight stone, which in my case came with the crock on top of the whole cabbage leaves. Press down firmly so that the liquid covers the stones at least 1-2 inches. Add cooled brine water to compensate ,if need be.
Place the lid on top of crock and fill basin with water. This creates the air tight seal needed to begin the fermentation process. Set the crock in a cool place out of the way undisturbed for anywhere between 2-6 weeks or longer. Do not open the lid during this time. With the crock I used , you do have to add water to basin as evaporation occurs to maintain airtight seal. The time spent fermenting depends on your taste preference. It’s something you must experiment with.
After the desired fermenting time has elapsed, remove lid.
There may be a whitish scum floating on top. Don’t be concerned. It’s perfecting normal yeast formation. Carefully using a spoon , spoon it out and discard.
You may not get all of the yeast scum, that’s okay. It won’t hurt you.
Remove the weights and large cabbage leaves from the top.
Begin placing you sauerkraut in sterilized jars that seal air tight. Top off each filled jar with the liquid in crock. Make sure the sauerkraut is covered with the liquid and seal jars.
You could seal jars in a water bath and store on shelf. I did not do this however I store mine straight into the refrigerator. It will last up to 6 months in the refrigerator providing its in a air tight container and the juice is over the top of the sauerkraut.