I have a wonderful Harsch fermentation crock. But, I haven’t used it to make sauerkraut in a long time. That is mostly because I don’t have much need of 5-liters of sauerkraut these days. I would rather make a quart or two of sauerkraut at a time.
There are many ways to ferment foods in small batches. The most simple method is putting the salted food in a jar and covering it with a lid. However, this method tends to be messy and carries the risk of exploding jars (i.e., due to the build-up of fermentation gasses).
Some people have borrowed a little know-how from the beverage industry, and adapted their airlocks to fermentation in a canning jar. Airlocks for canning jars are usually added through a hole bored in the jar lid. A Google search will turn up several tutorials on how to make a DIY canning jar airlock. I planned to make my own. But after a couple of years of planning to do so, I have realized that I am just too busy. So, I purchased some fully constructed canning jar airlocks.
A variety of canning jar airlocks are available for purchase. I purchased a set of three Kraut Kaps (#1 and #2). The Kraut Kaps include an airlock and a plastic canning jar lid with a hole drilled in the center. The jar lid includes a silicone washer that lines the hole, and a silicone sealing ring that goes inside of the lid. I also purchased three Crock Rocks(#1 and #2). They are heavy glass weights that are sized to fit inside a wide-mouth canning jar.
To make the sauerkraut, I first gathered my supplies (#1). That included a quart-sized mason jar, the Kraut Kap, the Crock Rock, canning salt, cabbage, a scale, a knife and cutting board. I washed the jar, lid, airlock and crock rock in hot soapy water, and put them on a clean paper towel until I needed them.
Then I peeled off the outer layers of my cabbage, removed the core, and then sliced it as finely as I could. I put all of the cabbage into a bowl on a scale, so that I could weigh it (#3). As you can see, I didn’t do a great job, but I was going with it any way.
The general rule of thumb is that you need three tablespoons of canning salt for every five pounds of cabbage. Since I needed about 2-pounds of shredded cabbage to fill my quart jar, I also needed about 1.3 tablespoons of canning salt.
After I shredded and weighed the cabbage, I sprinkled the salt over it and stirred (i.e., tossed) it well with my hands. The goal was to get the salt fairly well-distributed throughout the cabbage.
Then I let the cabbage rest for about 30-minutes. Every so often, I tossed the salted cabbage with clean hands, and then firmly squeezed it in my hands. During that time, the salt began to draw out the juice from the cabbage. You might think that it would get mushy, but it doesn’t. This process just reduces the volume of the cabbage and makes a brining liquid.
After 30-minutes, I tightly packed the cabbage into the mason jar. (I had too much cabbage, so I rinsed off the left-overs and gave that to Mr. PR for a snack. It was salty but still tasted good.) I placed a cabbage leaf over the top, and a crock rock on top of that. I also added the brine in the bottom of the bowl, so that the cabbage was covered by more than an inch. I was supposed to leave at least 2-inches of head space, but it turned out I didn’t measure very well (OK I just estimated and didn’t measure), because my jar eventually cracked (more on that below).
I screwed on the lid (with the silicone gasket inside of it) until fairly tight. Then I assembled the airlock (#4 and #5). The airlock uses water to create a one-way gas valve, so that fermentation gasses can get out, but air can’t get back inside the jar. The prepared airlock was pushed into the hole in the center of the lid.
I kept the jar on a shelf over my kitchen sink (no window there). It is convenient because it is a warmer location (we are keeping out house down around 60°F) and I see it all of the time. I have found that I forget about my ferments if they aren’t where I see them all of the time.
After an hour or so, I noticed that the inner part of the air lock was pushed up to the top (lid) of the device. At about 8-hours, I noticed bubbles forming (#6). I also noticed that the cabbage has expanded quite a bit. In fact, the top of the brine was almost touching the inside of the lid. Since the cabbage was full of bubbles, I think the bubbles pushed some of the brine up out of the cabbage.
At that point, I probably should have opened my jar and taken out some of the cabbage. But, I thought that I might still have some headspace left. The brine wasn’t coming out of the airlock, so I thought it would be OK.
Well, I was wrong. 🙁
Sadly, pressure built up in the jar and the jar cracked. Thus, I had to throw away my partially fermented cabbage.
Oh well. Tomorrow I will pick up some more cabbage and give it another try. 😀