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.
