The somewhat-green sauerkraut on the left has just been made and fermentation hasn’t begun. The white sauerkraut in the middle was made 2 to 3 weeks ago and is ready to enjoy. The brown sauerkraut is over a year old; it is soft in texture and sour in flavor but still edible.
There is a foolproof method for making sauerkraut and other ferments and that is to use glass canning jars, filled to the very top with vegetables and brine. I adopted this method when I was doing a lot of recipe testing for my book, The Pickled Pantry, and I haven’t had a ferment go bad or taste funky ever since.
Why is it foolproof? Glass, unlike crocks, never develop the hairline cracks that make a crock impossible to sanitize properly, and the cracks allow contaminants in. A glass jar with a lid and screwband excludes air without the need to weight the food to keep it below the brine. When you want to check on the ferment, you can see how it is progressing without opening the jar and introducing airborne yeasts and molds. And, when you want to taste your ferment, you open and taste from one jar, leaving the rest of the jars in your batch unopened and unexposed to air.
If you taste the unfermented cabbage, it will taste salty. As fermentation proceeds, lactic acid is produced as a byproduct of the microbial action, and the sour should balance out the saltiness. The more salt you use, the slower the fermentation and the longer the kraut will keep without softening; the less salt you use, the quicker the fermentation and the faster it will soften and discolor.
As the fermentation proceeds, you will see bubbles of gas – carbon dioxide – rising to the top of your jar. It will even push some brine out, which is why I always place my ferments on saucers to catch the overflow. If the fermentation is vigorous, it may even leave some some of the vegetables uncovered on the top. This isn’t a problem as long as the jar remains closed. When I open the jar to taste the ferment, I’ll top it off with more brine (or just water if the ferment tasted salty) to keep it all covered. Then the lid and screwband goes back on.
Potential problems? Just one: If you fail to loosen the screwband as fermentation begins and carbon dioxide begins to build up in the jar, you could get an explosion (It happened to me once with kimchi all over the kitchen; it won’t happen again!).
You can buy airlocks for glass canning jars. They aren’t expensive and they do work well, but the only advantages they provide are that the airlocks remove the need for placing the jars on saucers to catch an overflow and they prevent explosions. On the downside, when you open the jar to taste the ferment, the air you let in will contain yeasts and molds that will form a scum on the top of the brine, which you will then have to remove. To remove the scum, you have to open the jar, exposing the brine once again to the airborne yeasts and molds. And so on. (This same issue occurs with expensive crocks.)
The method of making ferments in canning jars is only slightly different from the standard method of making ferments in crocks or other vessels.
Step 1. Wash your jars and lids in soapy water. Rinse well and set them upside down on a towel to drain and dry.
Step 2. Trim the cabbage and weigh it. Measure out 1-1/2 teaspoons of canning salt or fine sea salt per pound of cabbage and place in a small bowl. Shred, grate, or chop the cabbage and place it in a large bowl or food-safe bucket. If you are working with multiple heads of cabbage sprinkle on a portion of your measured salt as you fill the bucket with the shredded cabbage.
I like to use a mandoline for shredding cabbage. Cabbage grated on a box grater or with a food processor looks chewed up to me and sauerkraut made from chopped cabbage doesn’t fit neatly on a hot dog.
Step 3. Mix the cabbage and salt. If you like, walk away and let the salt pull the liquid from the cell walls. If you want to wrap the job up, smush, smash, and massage the cabbage until you have mechanically broken down the cell walls and drawn water out of the cells. (A combination of both — time and massage — is fine.) The sauerkraut is ready to pack when it has a good amount of brine in the bowl. Note: Sauerkraut made with freshly harvested cabbage generates brine easily; sauerkraut made with cabbage that has been pulled from the root cellar may need added brine (see step 4).
A few hours after salting the cabbage, the cabbage is wilted and brine has collected in the bowl.
Step 4. Pack the cabbage into the canning jars, tamping down with a dowel or spoon. Fill the jar with cabbage to within 1 inch of the top of each jar, tamping down as you go. At the top of the jar, you should have about 1 inch of brine, filling the jar to the very top. If you don’t, make some brine by combining 1 cup spring water (i.e., non-chlorinated water) and 1 teaspoon canning or fine sea salt and add as much as needed. Place the lid on the jar, place the screwband on the jar to secure the lid, and gently finger-tighten. Place each jar on a saucer or place all the jars in a plastic bin to catch the overflow.
I use a dowel to tamp down on the cabbage as I fill the jars.
I fill the jars to the very brim, then top with the lid and screwband, and place on a saucer to collect overflowing brine.
Step 5. Let the fermentation happen. Sauerkraut takes 7 to 14 days to ferment in glass jars at 60 degrees to 70 degrees F; it will be slower at colder temperatures and faster at warmer temperatures. I keep my ferments on the counter (or where I can see it) for 2 weeks. If the lid bulges at any time, loosen the screwband. If there is no brine overflow after 2 days, loosen the screwband. After 2 weeks, the ferment should no longer be pressing out brine, and a jar tipped on its side will not show many or any gas bubbles rising up.
Step 6. Taste. The ferment should taste pleasantly sour. If it does, it is ready to be stored. If it is still not sour, let it ferment longer. Remember to taste from only one jar, and to refill to the top with more brine (see step 4) if needed.
Step 7. Store. Keep never-opened jars in a cool place (a cool basement or a refrigerator) for up to a year. It can go even longer, especially if extra salt is used, but the longer it is kept, the sourer it becomes. Once a jar has been opened, keep it in the fridge. Try to avoid having anyone eat directly from the opened jar. If it ever turns out the sauerkraut is too salty to enjoy, give it a quick rinse under running water.
Andrea Chesman has written more than 20 cookbooks, including The Pickled Pantry, Recipes from the Root Cellar, Serving Up the Harvest, and The Backyard Homestead Book of Kitchen Know-How. She teaches and does cooking demonstrations and classes at fairs, festivals, book events, and garden shows across the United States. She lives in Ripton, Vermont.
All MOTHER EARTH NEWS community bloggers have agreed to follow our Blogging Best Practices, and they are responsible for the accuracy of their posts. To learn more about the author of this post, click on the byline link at the top of the page.