Thursday, February 28, 2008

Secrets of Sauerkraut

After about five years of experimenting with making sauerkraut, I've finally figured out how to do it reliably. I'm going to share the secrets. Some I got from a version of the USDA Complete Guide to Home Canning that is no longer available online. Some was from Ohio State Extension. Some is hard-earned experience from making mistakes or having a lucky inspiration.

First, grow your cabbage. Sauerkraut is best made from freshly harvested cabbage. USDA says "between 24 and 48 hours after harvest". I suspect this requirement is because the lactic acid bacteria (lactobacilli) population that is native to the leaf surfaces begins to die off in stored cabbage. I pick and partly clean the cabbage the day before processing, cutting off roots, discarding dirty outer leaves, and rinsing off any remaining dirt. Soaking would probably be a bad idea. Then I just leave the heads out on a clean work counter overnight.

The timing of harvest and the variety of cabbage are important. My early trials were poor because I kept thinking of sauerkraut as a fall harvest task and trying to do it in late September. This is wrong for two reasons. One is that a certain temperature is needed for fermentation. The other is that cabbage tends to split as it gets mature and if there are cool nights with good soil moisture. Last year I chose an early-maturing variety, "Gonzales", a real mistake; I lost 1/3 of my crop to split heads even though I harvested over Labor Day weekend. Gonzales is meant to make "miniheads" for fresh eating during the summer - I must not have had my reading glasses on when I chose it. Other years I have grown "Stonehead", with some splitting but perhaps not so early. This year I'm going to try a mix of Stonehead and "Tendersweet", a flatter head that is said to be resistant to splitting. For the last two years, I have harvested and made the kraut around Labor Day, with good results. Temperatures are warm but not too warm during fermentation.

For processing, the heads are cut into quarters, outer green leaves and cores removed, and then shredded. Unless you have amazing technique, shredding with a knife blade is too uneven as well as tiring, and a food processor makes shreds that are too coarse. In past years I used a mandoline, inefficient and time-consuming but with good results. Finally I broke down and bought a real kraut shredder, or as they are called, a krauthobel. I have concluded that all these come from the same factory in Slovenia. It is like a huge mandoline made of wood with multiple blades and a square box that rides over them. No pressure is required on the cabbage to make the cuts.

I trust stoneware crocks best for fermentation and pickling. Some people use plastic buckets but the references I consulted warn against using anything but food-grade plastic. The crocks are prettier anyhow. Old ones are fine if they are not cracked, but new ones are a good investment. A 3-gallon crock will make 15 lbs of sauerkraut, and a 5-gallon crock will make 25 lbs. Then a plate that just fits inside the crock is needed to press down the cabbage and help keep out molds.

The salt used should be pickling salt, or kosher salt would probably work. Pickling salt is of a high purity without iodine. In old recipes you will find different amounts of salt used, but I try to keep to a strict ratio of 3 tablespoons to 5 lbs of shredded cabbage. I shred cabbage and weigh it in a large bowl until I have 5 pounds, then mix it with the salt and put it into the crock, with pushing down to express juice. I finally bought a hand-crafted sauerkraut stomper from Lehman's ; it looks like a table leg but really works.

After the crock is filled to a few inches from the top, put a plate (best fit) over the cabbage and press down. Brine should come up over the plate. If it doesn't, the cabbage can be topped off with boiled and cooled brine ( 1 1/2 tablespoons pickling salt per quart of water). Weight the plate with a couple of clean quart jars filled with water. By now the crock should be resting where it is going to stay for 4-6 weeks, in a place with low traffic and relatively constant temperatures. Drape a clean tea towel over the jars and crock, then a heavy bath towel over that. Disturb as little as possible, but check after several days and then weekly to see if any molds or yeast scum need to be removed. Some foam formation at first is expected, since the bacteria are producing carbon dioxide. According to Ohio, when temperatures are between 55-65, fermentation will take place in 5-6 weeks. At 70-75, it is 3-4 weeks. Much cooler and it won't ferment. I had to throw out my entire batch one year because it never fermented, and other years when it was too cool, the brine turned a dark brown over an exceedingly long fermentation time. Ohio says that above 80 the cabbage may spoil. According to my max/min thermometer last year, temperatures through September were 64-76 and the kraut was perfectly fermented in 5 weeks. Small amounts can be taken out with a clean fork and tasted to see whether it is "done".

My friend Dan, who helped last year and carried away some of the cabbage to ferment on his own, refrigerated all of his and is still happily eating it out of his refrigerator. He believes that the lactobacilli are healthful. I canned most of mine in glass jars (hot water bath method) and this is perfectly satisfactory for most cooked dishes. However, with Dan's encouragement, I kept several quarts in my refrigerator and this made a lovely fresh kraut slaw with just a little vinaigrette.
UPDATE:  A better description of the process as done in my kitchen, complete with stepwise pictures, can be found on The Farmer's Marketer post Homemade: Sauerkraut.  Highly recommended.


Mom said...

I love canning! FYI, the USDA guide to home canning can be found here on line:

Also, there is an Ann Arbor home canning group - it can be found here:
Hope this helps!

Vivienne said...

Hi Mom! I'm honored.

Thanks for the updated website link.


BloomingtonGirl said...

We put in a huge garden this year and we plan to make pickles and sauerkraut. Did you think a sauerkraut board or wooden crock topper is worth it?
I am going to buy a 2 gallon crock along with your recommended stomper.

Buttercup said...

Hey BG, sorry I didn't see this earlier. I hope that you haven't bought your crock yet because I recommend a 3 gal crock for general fermentation and pickling use. It will last for generations. A 3 gal crock will hold 15 lbs of sauerkraut.

The wooden crock topper is iffy. I bought two, one for each crock size. I like them and they are useful but being wood, they can warp and mold when not in use and if not cleaned adequately. I'd love for some enterprising potter to make ceramic weights to fit crocks so we don't have to search for the perfect plate.

Buttercup said...

New information: from the Weston Price foundation, I found this quote:

During the Civil War, some enlightened doctors fed sauerkraut to prisoners of war, reducing the death rate from smallpox from 90 percent to 5 percent--something we should take note of with the current concerns about the use of smallpox germs as part of biological warfare.