Sauerkraut II - the science and art of lactofermentation

[Troy McClure]

Ok I've been reading up on all the different ways people make sauerkraut - its fascinating stuff. Here is what I found out so far:

The science of fermentation is based on creating anaerobic conditions - i.e. no oxygen. We want the anaerobic lactic acid producing bacteria to proliferate. RULE #1 - No Oxygen.

There are 2 ways of creating an anearobic environment:

1. Using Brine - either the juice from the vegetables, or by adding salt water (usually a combination of both is employed).

2. Sealing the container

These 2 methods have been known since at least Roman times (they are mentioned by Pliny).

Method 1

We add salt to the ingredients because salt draws out water via osmosis (cabbage is 90% water). This can take up to 24 hours, which is why you may not get much juice at first. (this is what happened to me!)

The juice is important because it is this which contains the sugars on which the lactobacteria can feed and proliferate.

Pack and tamp the ingredients into a crock.
Place a plate on top, inside the crock, and place a clean weight on top.

Periodically (every few hours) press down to force water out until the brine rises above the plate.

If this doesn't happen within 24 hours, add salt water to bring the brine level up to the plate. (1 teaspoon salt to 1 cup water).

This method doesn't require a sealed lid - just something (e.g. a cloth) to stop things falling in to your brine.

Place the jar in a dark place where it won't be disturbed and where it can ferment at a temperature of 70 to 75 degrees F. Check the jar frequently -- every day or two -- for signs of scum or yeast. Remove any spoilage immediately.


Method 2

Again we pack the ingredients in as before. But this time we fill the container until not much air is left. This time it doesn't matter so much how much brine there is as the air supply is limited. Though you obviously need a container with an airtight seal, and my guess is that you should almost fill the container so that not much air remains.

A couple of really useful guides I came across:

This first one has a great set of pictures of the entire process. Very simple:
http://www.kitchenproject.com/german/sauerkraut/

This one is a great guide telling you all the things to watch out for, and many ways to extend the basic recipe:
http://www.wildfermentation.com/makingsauerkraut.htm

Finally this is for the geeks amongst you! Some real science:
http://www.splammo.net/foodapplmicro/applkraut.html
That page looks at "wild fermentation" of sauerkraut - where no exogenous bacteria is added, instead the normal flora of the cabbage leaves is relied upon. Amazingly there is a 3-stage succession of dominant flora, governed largely by PH. Initially a coliform bacteria starts fermentation. As acid is produced a strain of Leuconostoc bacteria takes over. Finally as ph continues to drop, a strain of Lactobacillus takes over. The experimental results at the bottom of the page indicate that this process takes roughly 5 days, by which stage lactobacteria count is maximal. This count declines somewhat with age, as more lactic acid is produced up till full maturity at 5 weeks.


Enjoy!!

Some questions which remain unanswered:
1. How does the size of the shredded cabbage affect the packing and brine quantity? My guess is that finely shredded cabbage may be easier to pack and produce more brine.

Answer: Apparently you want long thin slices of cabbage. Thin because you want as much surface area as possible for the fermentation to act upon.

2. When using the seal method, how much air can we get away with containing?

3. How long will fermentation take? Nourishing traditions says 3 days. Kitchen project says 10-14 days. Wildfermentation says 1-4 weeks.

Answer: According to the most authoritative guide - the 3rd link above - which details the science behind lactofermenation, 5 days seems long enough. Also endogenous fermentation takes longer than when an external source is added (e.g. whey). Adding whey (or some other starter culture) speeds up the fermentation process drastically.

Also Wild Fermentation says: "My practice is to start tasting ferments when they are young and continue enjoying them as their flavors evolve. After about 3 days I can usually taste a distinctive sourness, that intensifies over weeks and sometimes months. Usually I like about 2-3 week old kraut best. Much depends upon what the room temperature is; higher temperatures speed the process, cooler temperatures slow it. Similarly the time of fermentation varies with salt levels; the saltier it is, the slower the process. Hope you enjoy the kraut! It's my favorite food."


4. What does finished sauerkraut look/taste like?
According to Wild Fermentation:
"Sauerkraut should taste decidedly salty, but not unpleasantly so. The brine will likely be cloudy, and more so over time. The solid volume will reduce and the liquid will rise a bit in the early days. You may see bubbling or even some foam. It is not uncommon for mold to develop on the surface of the kraut. Skim it off as best you can."

5. The smell during fermentation is almost overwhelming. Any suggestions?

WF: The only suggestion I have is to find an out-of-the way place: a porch, basement, garage. Fermenting sauerkraut has a distinctive smell.

Further info: I just found this new yahoo group on Fermented foods - it looks great!
http://health.groups.yahoo.com/group/Microbial_Nutrition/

[shelley]

[Troy McClure]

Thanks Shelley - I've updated it. If you get time let me know what you think.

[shelley]

great again!

[ono]

Thank you for all the great links and research Troy! I love food and anything having to do with food. Nice to see others with similar interests!

[Troy McClure]

Thanks ono, I'll continue to update if I find/learn anything new.

Of course the more people that try the more experiences we have to learn from. So I urge anyone interested in fermentation to give it a go!

[Rozenkwarts]

Thanks for the great information.

I have been wanting to make sauerkraut for a while. This is just what i needed to get started. Just need to get the right jar or pot to make it in.
Is a mason jar one of those glass jars that are used for sterilising? The glass lid sort of hangs off the jar with a metal hinge and its got a red rubber seal? Or is a mason jar something else?

many thanks,

[Troy McClure]

I have to admit I didn't actually know what a mason jar was!

A quick google provided the following info:

"In 1858, John Landis Mason developed and patented a shoulder-seal jar with a zinc screw cap. The "Mason jar" had a threaded neck which fit with the threads in a metal cap to screw down to the shoulder of the jar and in this way form a seal. In 1869, a top seal above the threads and under a glass lid was introduced to the jar. The screw cap pressed tightly against the inverted lid, with rubber seal underneath, thus effecting an excellent seal. Preserving food in a glass home canning jar had now been taken a step further. A type of this closure still is in use today, although augmented with various other closure designs."



Click Here for more Mason Jar Pictures

But the point is that you can make fermented food in anything (non-metallic). It doesn't even need an airtight seal if you use the liquid covering method.

Ceramics, earthenware and glass are good. Even plastics are ok. At the moment I'm using an old tropical traditions 1 gallon coconut oil bucket!

Long term I would prefer something else, but it will do for now! The important thing is to get fermenting!!

[shelley]

I was surprised by how small mason jars are! At least, the ones we stock in our garage are quite small, good for just one single cabbage. For some reason I had pictured this huge huge jar that would take up the entire floor of the pantry.

[Troy McClure]

You are right Shelley:

"Regular and wide-mouth, Mason-type, threaded jars with self-sealing lids ... are available in 1/2 pint, quart, and 1/2 gallon sizes. The regular jar mouth opening is about 2-3/8 inches. Wide-mouth jars have openings of about three inches, which makes them easier to fill and empty."

At the moment I'm ferminting only one cabbage at a time(until I learn the ropes). But really fermenting is best done in batch, so the bigger the container the better.

Just take a look at these guys:

http://www.schmarder.com/dave/sauerkraut/

[shelley]

I'm not real big on regular sauerkraut, but I adore Kim Chee. I'm thinking of trying this recipe:

http://www.thegutsygourmet.net/kimchee.html

[Troy McClure]

I'll let you in to a little secret ... sauerkraut is just a means to an end!

I don't imaging making vanilla sauerkraut too often either. There are just so many yummy things that can be added to make either cortido (the mexican version) or as you say Kimchee (the korean version). I'm a spice junkie.

Or even a totally new dish - thats the great thing about fermented foods - each batch is entirely individual.

But the basic process is exactly the same, so Sauerkraut is a fantastic recipe to try. If you can make Sauerkraut, you can make any fermented food.

My sauerkraut should be done in a day or two and I'll move on to either Cortido or Kimchee.

[Rozenkwarts]

Hi Troy,

Thanks so much for looking up the mason jar info. I get the picture now

I'll let you know how the sauerkraut comes along when i eventually get round to making it!

For now, i just got some at the health food store. (the refrigerated kind, comes in a bag) I like it both warm with pork sausages and cold as a salad with lettuce, tomatoes, beets etc.

Take care,

[Rozenkwarts]

Hiya,

Just thought i'd let you know that i finally got round to starting my sauerkraut yesterday. I just sliced up a cabbage, added the salt and pounded it with the end of a rolling pin until there was enough juice, then i fitted a small plate on top. This morning there was already some brine leaking up over the plate so i think it's going ok. I didn't have any caraway seeds so didn't add anything. Would you add juniper berries to the sauerkraut?

Thanks again for the recipe and tips,

i'll let you know in a couple of days how it comes along

[Troy McClure]

Juniper Berries sounds great!

How did your sauerkraut come along???