How to make the best sauerkraut?

Our family recipe, but I don't remember the exact values especially for the caraway seed, so take it with a pinch of salt ;)

10 kg cabbage, sliced

200 g salt

1 kg carrots, cut into small slices (max 3 mm thick)

1 kg leek, cut into small slices (around 5 mm thick)

20 g caraway seeds

Correct sized stone for your jar, cleaned and cooked in boiling water for sterilization

• Cut everything but keep 2 of the outer cabbage leafs per jar, select good looking leafs and just clean them
• Mix everything in a big tube/vessel really well, so the salt starts extracting the liquid from the cabbage
• Put the mixture into the jars and use your fist to make it compact
• Important part 1: there needs to be at least 1 cm of salty liquid above the kraut at the end, if there isn't just add 10 g salt to 100 ml water and add enough of that solution as necessary
• put the two leafs on top of the kraut to push it down and keep all the small bits from flowing around in the salt solution
• place the stones (in middle Europe you can buy special ceramics like this for this purpose, but a simple stone of the right size or 2 is enough) on top of the leafs to push them down
• close the jar and fill the groove with water
• important point 2: the grooves has to be filled with water all the time to stop mold from forming
• now place the jar for 2 weeks in a normal heated room. Check the water level in the groove. You will hear air bubbles flowing through the water trap, which tells you that the fermentation is proceeding nicely.
• when no air bubbles are forming for a day, fermentation is over and you can eat it and place it in a cold room for better storage.
• again: keep checking the water level in the groove
• when you take out sauerkraut, always check that the walls above the water level are mostly clean and not to many loose parts are swimming through the salt water. Those are the regions where mold will start forming.
• also refill the water level inside with the salt solution if too much evaporate.
• always clear the solution with the leafs and put the stones on top and you will enjoy it for a long time (5 months are possible)
• you can also freeze fermented sauerkraut to thaw it when needed and stop it from molding

My Polish father in law makes it with bacon and it is by far the best fermented food I've ever enjoyed. I'll see if I can get the recipe.

The Germans I know don't make sauerkraut, they buy it (usually; my grandma probably knows how to make it, even if she doesn't always do it). Ain't nobody got time fo dat!

A mandoline slicer makes the chopping much faster if you have one.

I like caraway seeds in mine.

I ferment on the top of my cabinets in a mason jar, then move to the fridge when it starts tasting right.

Not German (except by ancestry), but my advice is that you might want weights or airlock lids for the jars.

(Not sure what the pros/cons are of the two different styles of keeping the cabbage submerged.)

Otherwise, a Ziploc bag full of water can do the same task in a cheaper/jankier way.

Once it's finished becoming sauerkraut, you store it by putting a regular airtight lid on it and putting it in the fridge. I suppose it could also be canned to make it shelf-stable long-term, but you're going to want to look up reputable advice for that.

As far as what to add beyond salt and cabbage, since you have a bunch of jars I suggest experimenting with a bunch of different things.

My step-grandmother made it in a 10 gallon barrel and used the end of a baseball bat to pound it down. Then put an ancient plate with bricks on it to keep it compressed while it cured. Sadly that seems to be all I remember.