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Home made Sauerkraut

Sauerkraut is very good way to preserve cabbage over a long period of time. It's rich in vitamins and the lactic acid bacteria, which are at the heart of this process, have health benefits too. The normal sauerkraut you buy in tins or bags at the store is "dead". They have to cook it otherwise the fermentation process would continue and the package would pop. Home made sauerkraut is the only one that has beneficial life Lactobacilli cultures in it.

delicious home made sauerkraut

The science behind Sauerkraut

Sauerkraut is about fermenting cabbage in an environment that allows lactic acid-producing bacteria to grow quickly. The lactic acid reduces the the pH and creates an acidic environment that is unsuitable for the growth of unwanted bacteria.

We have two main enemies at the start of the fermentation process: mold and yeast. We have to create an environment that prevents them from growing and favors lactobacilli. For this process to work in favor of lactobacilli (the lactic acid-producing bacteria) one has to ensure that there is no oxygen (or very little) in the fermentation container (a crock works well).

Mold and yeasts and are all more robust with regards temperature range and salt concentration than lactobacilli but both mold yeasts need oxygen. Lactobacilli however grows best without any oxygen. Thus to get good Sauerkraut you have to minimize the amount of oxygen. We achieve this by salting and compacting the fresh cabbage until all the cabbage is completely covered in its juices.

A 10 liter crock

The container has to be big enough to hold 4-5 medium sized cabbage heads. I recommend to use a crock made of pottery clay or porcelain. A 10l (3 gallons) crock (or bigger) works well. You need a good amount of cabbage to get enough liquid out of the cabbage by compacting it. The surface exposed to air has to be very small compared to the total amount of cabbage.

A medium sized, 1.5kg white cabbage head, it's the type we find in any supermarket

It's a good idea to buy at least some of the cabbage from a farmer and not a supermarket. The reason is that supermarkets require that all salad and vegetables are free of living insects. To achieve this requirement all cabbage sold via supermarkets is dipped into a liquid that is toxic for insects. This removes unfortunately not only larger insects but as well a lot of the naturally occur lactobacilli from the cabbage heads. There will still be some lactobacilli left and it will eventually work but the start of the fermentation process works better with more natural cabbage.

Different cabbage types, the big cabbage head on the right is known as Baladi Cabbage

There are as well different cabbage types. All of them seem to be sold under the name cabbage so I don't know if there is actually a distinguishing name for those different types. The best cabbage is a softer type that comes in big heads which are not round. They are squished and flat at the top and this type of cabbage produces more juices. It's the cabbage head shown on the right in the above picture and it is not easily found in the normal supermarket. It is known as Baladi Cabbage.

Let's make Sauerkraut

Shred the cabbage with a cabbage shredder, one cabbage head at a time.

A simple cabbage shredder

I use a large plastic bowl to hold the shredded cabbage. The large bowl makes it easy to add salt evenly to the cabbage after shredding.

Shredded cabbage

It's very important to use the right amount of salt to get good sauerkraut. You need about 15g - 20g (one tea spoon) of salt per cabbage head. The salt causes the cabbage to free its juices and this makes the brine which is very important for the fermentation process.

Give a few hand full of cabbage into the crock and then compact it. A round arm sized piece of untreated wood works well as a compactor. I recommend to use wood that does not change the flavor of the cabbage. Avoid e.g ceder and oak. Birch, maple and beechwood work well.

A cabbage compactor.

You can add fresh wine leave to the cabbage.

Fresh wine leaves

I add a layer of shredded cabbage. I compact it and add a wine leave before I add the next layer of cabbage.

Do not fill the crock to the edge with compacted cabbage. Leave about 2 inch (5cm) space. The fermentation process will produces gases (CO2) and the brine will raise a bit while the gas bubbles slowly to the top.

Keep compacting the shredded cabbage until you see juices coming out of the cabbage. Close the crock and cover the cabbage with plate that is just small enough to fit into the crock. Put some weight onto the plate (a big jar or a large vase full of water works well). You should see a bit of brine appearing in the small space between crock and plate. Nice juicy cabbage produces a lot of brine but sometimes I had rather dry cabbage and I would not see brine immediately. To prevent oxigen from getting into the sauerkraut it has to be covered in liquid. You need to add brine if there is not enough natural brine.

Adding additional brine: Boil water in a pot in order to remove the chlorine and any oxigen disolved in the water. Cover the hot water and let it cool down to room temperature. Add some salt (about a table spoon for 1 liter of water). Add this brine to the cabbage until it is completely covered. Normally you will not need much additional brine. A cup or two is usually enough.

The gases formed during the fermentation process in the lower layers push the brine up to the top. You have to make sure that there is enough space in the fermentation crock to allow the brine to raise without overflowing. You will usually see the most amount of brine after about two days. The level will go slightly down as the fermentation process slows down.

The brine between cover plate and the crock wall will keep oxygen away from the cabbage and prevent the formation of mold or the growth of yeast cultures.

The brine keeps oxygen away from the cabbage

The sauerkraut needs about 2 to 4 weeks (depending on the temperature) until it is ready. You will have a mild sauerkraut after 2 weeks and it becomes stronger (more acidic) over time. It can be kept and eaten over course of several month.

I have obtained the best results when the crock was kept at a temperature of around 15'C (60'F). It seems to me that warmer temperatures favor mold and yeast over lactobacilli especially during the first few days.

A well ventilated garage that is attached to the house is a good place to keep the crock. A well ventilated garage is not only good because the exhaust fumes form the car can dissipate. The fermentation process produces gases and they smell a bit. It's not a strong odor but you don't want it in your living area either.

White film, mold, slime

It may happen that some mold forms on the walls of the crock above the actual Sauerkraut. The cause is usually an individual piece of cabbage sticking to the wall or some foam bubbles form the brine sticking to the upper wall of the crock and starting to dry out. Just take a wet cloth and remove the mold. The mold is not harmful because it has not been in touch with the brine or the actual sauerkraut.

A white film may form on top of the brine or on cabbage piece that is sticking out of the brine. It's a friendly pro-biotic yeast. You can remove it with a spoon if it is excessive.

A thick white slime can form if not enough salt was used to prepare the cabbage. Remove the slimy layers. The sauerkraut underneath will usually be OK and can still be eaten.

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© 2004-2024 Guido Socher