Special to The Washington Post When Doug Wetzel sat down for Thanksgiving dinner soon after he moved to Petaluma, Calif., he surveyed the table. His hosts, who owned the artisanal bakery where he worked, seemed to have everything right: 'turkey and stuffing and oven-roasted Brussels sprouts.' But when Wetzel asked for the sauerkraut, he says, 'they all looked at me like I was crazy.' Wetzel, 26, grew up in Baltimore, where fermented cabbage is as commonplace as cranberry sauce for the November holiday, even for those without German names. 'I knew better than to ask for candied yams with marshmallows' at such a spread, says Wetzel, now pastry chef for Gertrude's restaurant at the Baltimore Museum of Art. 'But the fact that there was no sauerkraut was kind of a shock.' Richard Kissling, chief officer of A.C. Kissling Sauerkraut in Philadelphia, says his Charm City sales surge each year in early November to five or six times the usual volume. 'In Baltimore, it's just one of those traditions,' he says. 'I don't understand it.' The city's German immigrants accounted for about a quarter of its residents in 1863, when Abraham Lincoln declared Thanksgiving a national holiday. They brought their everyday dish of sauerkraut to the New World. 'Whenever people would get together for a special occasion, sauerkraut would be involved,' says William Woys Weaver, Pennsylvania food historian and author of the book 'Sauerkraut Yankees.' Sauerkraut-based dishes on Baltimore's Thanksgiving sideboards might include a bowl of the stuff straight from a bag or jar, braised sauerkraut with apples and bacon, or sauerkraut with ground pork, rolled in cabbage leaves. Sauerkraut can even be used for stuffing the bird. Plenty of Baltimore natives with Baltic roots remember a mother or grandmother brewing sauerkraut in a container in the basement. When Marc Attman of Attman's Deli was 9 years old, he was given the job of chopping cabbage for the sauerkraut served there. The finished product would sit in a barrel in front of the store, Attman says, 'and if someone wanted to try it, they'd just stick in their fingers and take a little bit.' Now the deli gets its kraut from Pennsylvania, and if someone wants a taste, 'we get out the rubber gloves and the tongs,' he says. Much has changed in the world; sauerkraut, it seems, has not. Weaver says fermented cabbage can be traced to the Byzantine Empire. It shows up in cultures all over the world, with close relatives in dishes such as Korean kimchi. High in vitamin C, the fermented cabbage is a breeding ground for lactobacillus, which helps with human digestion. It's a more earthy source of the probiotic than, say, the Activia yogurt hawked in television commercials by Jamie Lee Curtis. Generally available for less than $1 per pound, sauerkraut is relatively cheap nutrition. Though it involves only cabbage and salt, preparing sauerkraut at home requires a lot of planning. The process can take anywhere from three to eight weeks, depending on the temperature and a willingness to put up with the beery smell of fermenting leaves. Bonnie North, leader of the Baltimore chapter of Slow Food USA, has been dubbed 'Kraut Mother' by the staff at Gertrude's for her willingness to monitor four large, new plastic garbage cans of fermenting kraut in her basement. The finished product is served at the restaurant's annual Kraut Fest, held in early January. In a week or so, staff members at Gertrude's will start their annual process: shredding about 200 pounds of cabbage, tossing it with sea salt, then placing it in the 30-gallon containers a few inches at a time, mashing each layer to crush the membrane of the leaf until juice oozes out. The containers are then hauled to North's basement. 'There's no water involved,' North says. But as the lactobacillus eats away at the cabbage, natural liquids are released and bubble to the top. Every few days, North ventures down to her smelly cellar and dismantles the setup of each can: the heavy pail of water acting as a compressing weight on the large container, the clean plastic bag that keeps air out, the soaked napkins directly on the cabbage itself (which she either replaces or rinses). She then skims off any liquid and foam from the mixture beneath, checking that everything is the way it should be: moist but not soupy. 'I taste it to make sure it isn't rancid and then close it up again,' she says. Gertrude's Kraut Fest started about six years ago, when the restaurant's chef, John Shields, hired a sous-chef from Croatia. Shields, who delights in talking about his German grandmother, Gertie (for whom the restaurant is named), found a comrade in Tomislav Niksic. Niksic's own grandmother, Maria, had helped her village after it lost most of its men in World War II by taking on the strenuous task of pounding cabbage to make sauerkraut. 'She also went around the village helping people butcher the pigs,' Niksic says. While sharing Granny stories, the two found that, though their kraut-prep methods differed slightly, the outcome was the same. They decided to have a sauerkraut cook-off of sorts, each contributing recipes. What began as a couple of chafing dishes in Gertrude's bar area has evolved into a two-night party, with the restaurant closed for regular business to clear a space for dancing to live polka music. The menu of sauerkraut dishes includes vegan pasta, bratwurst and sauerkraut ice cream, with German beer to wash it all down. Niksic, now the chef at Le Meridien Hotel near Split, Croatia, says the main difference between the sauerkraut made in his grandmother's mountain village and the American version is that in his country, heads of cabbage are packed whole between layers of shredded cabbage. There's also a variation he calls 'winter salad,' in which pickled carrots, broccoli, cauliflower and peppers are part of the mix. In Croatia, the barrels are stored in the cellar. Some dirt-floored cellars were dug deeper than usual to ensure a cool, dark fermenting spot. Late-harvest cabbage with tight leaves was best for the job, so kraut generally was started in late autumn, at the time hogs were slaughtered. 'People also started making their brandy then,' Niksic says. 'November was a time of hard work.' By late December, the meat was cured, the brandy was ready and the sauerkraut had reached its peak, just in time for Christmas. 'Like everywhere in the world, a celebration means a full table,' says Niksic. And in some places, a holiday table isn't really full without sauerkraut. Martha Thomas is a Baltimore-based freelance writer who previously had encountered sauerkraut only on her hot dogs at Fenway Park. 