Sauerkraut in a crock. Originally from China, sauerkraut can be made fresh at home

OF all the discoveries and inventions the Western world has inherited from the Chinese, the one that might surprise you is sauerkraut. The builders of the Great Wall were fed rice and cabbage. When winter came, the cabbage was preserved in rice wine.

It fermented, and sauerkraut was born - rich in vitamin C, potassium, and fiber - and low in calories.

The Tatars carried fermented cabbage to middle Europe where a new version evolved - cabbage fermented in brine rather than in wine.

If the only sauerkraut you've tasted came from a can, you have a treat in store when you make your own.

A small batch can be made in less than a half hour. Then it takes about three weeks to ferment.

Just you wait!

To make sauerkraut, you need cabbage, kosher or pickling salt, a crock, a tablespoon measure, a large enameled pan to hold five pounds of shredded cabbage, a scale, a stamper, boiling water, and some way to cut the cabbage.

The first step in preparing sauerkraut is to rinse all the utensils with boiling water to discourage growth of unwelcome microbes.

The second step is to trim the cabbage of unwanted leaves, rinse it if necessary, and cut it into halves or quarters.

The kraut is best if the cabbage is sliced to the thickness of a dime. These days the thoroughly modern cook might use a food processor for this purpose.

When you have shredded five pounds of cabbage into an enameled pan, add three level tablespoons of salt, mix it well to distribute the salt evenly, then let it sit for five minutes to wilt and weep. You may use clean hands to mix in the salt, or a scalded stainless steel spoon.

Place the crock where you want it to be for the next three weeks. Now dump the shredded and salted cabbage into the crock and tamp it down, gently but firmly.

Firm packing is one of the secrets of excellent sauerkraut. You don't want to leave any air in the crock.

You can tamp the cabbage by hand, though I've never tried it. We use a stamper, or stomper, made from an old broom handle fastened into a solid wooden cylinder five or six inches in diameter and eight or nine inches long. Stop when the cabbage is within five inches of the top of the crock.

If the brine doesn't cover the cabbage, you can add brine by boiling some water, cooling it, and adding to each quart of water 1 1/2 tablespoons of kosher salt.

Cover crock with two heavyweight plastic food bags, one inside the other, filled with brine and tied shut. The filled double bag must fit snugly against the inside of the crock to exclude air and airborne invaders.

Fermentation begins the first day and will be completed in three to six weeks, depending on the ambient temperature. At 75 degrees F., it will take about three weeks; and at 60 degrees F., about six weeks. At temperatures greater than 75 degrees F., the whole batch will probably spoil.

Once the fermentation is complete, the sauerkraut should be refrigerated. If you have a cold cellar where the temperature stays below 50 degrees F., you can trundle your crock of kraut into it and use it as needed, being careful always to replace the plastic bag carefully.

A second way to keep the kraut is to pack it into clean canning jars and process them in a boiling water bath for 15 minutes. This means the kraut has now been cooked.

That brings us to a third method for keeping the kraut - the one I use. I simply stuff the kraut into pint or quart zip-top freezer bags and pop them into the freezer. Frozen sauerkraut is as good as fresh from the crock.

Suppose you open your kraut crock and find that the sauerkraut has spoiled. What did you do wrong?

If the sauerkraut is soft rather than crisp, you may not have used enough salt, or may not have distributed the salt properly.

You may not have stomped out all the air, or put enough weight on top. Or the ambient temperature may have been too high during fermentation.

If the kraut is rotted, or dark, there was not enough brine to cover it, and it was exposed to air.

Suppose your kraut is pink. Start over again. The brine was too strong, the salt was not evenly distributed, or the kraut was not weighted properly during fermentation.

But - as should happen - suppose you open the crock and find the kraut is crisp and delicious. You'll want to do something besides heat it with caraway, coriander, or cumin.

So here is a recipe for you to try.

This sausage recipe was first prepared for me by a Hungarian woman, so I consider it to be, if not Hungarian, then middle European.

Sausage and Sauerkraut 1 1/2 to 2 pounds loose sausage 1 large onion 1 cup raw converted rice 1 egg 3 pounds sauerkraut

Mix sausage, onion, rice, and egg. Shape into large egg-shaped meatballs. In large kettle, put a layer of sauerkraut, a layer of meatballs (not too close together), a layer of sauerkraut, a layer of meatballs, ending with a layer of sauerkraut. Cover with water to about an inch above the kraut. The rice will absorb the water. Add more water during the cooking if it seems to need it.

Cover with a tight-fitting lid and simmer 11/2 hours on top of the stove. Keep warm until serving time. Serves 6. Serve with rye bread and sometimes with mashed potatoes. It is excellent reheated.