Pickled green walnuts are made from unripe whole nuts. Once pickled, they become like dry, black olives in texture, with a flavor similar to pickled artichokes. Fermenting them is a several month-long process, in which they are submerged in several types of brine with honey and malt vinegar. In the cookbook, Balla and Burns say they use them in their sweet potato salad, but that they pair well with olives and blue cheese.

There were also two sodas in their secondary stage of fermentation, sumac and honey ginger turmeric.

Sodas in their secondary stage of fermentation. Photo: Wendy Goodfriend

They source very few products from far away (ramps, sour cherries and bottarga, or Mediterranean cured fish roe, are a few), but sumac is another; on a visit to Madison, Wis., where Burns went to college, they were at the farmers' market and came upon a farmer selling the fruit, which is most often ground into a sourish powder to spice up Middle Eastern cuisine (fans of the Yotam Ottolenghi books will no doubt have it in their pantry). The farmer shipped some to Bar Tartine, where they soaked the stems and pods in warm water to extract the tannins. Later, they added whey, a byproduct from their house-made yogurt, and apple and pear juice with a bit of honey for sweetness. Fermenting causes natural carbonation to occur, resulting in a refreshingly sour soda. Their honey ginger turmeric soda is made from a probiotic non-dairy kefir (kefir is usually a fermented milk product) made with fresh turmeric grown in Sebastopol.

House-made honey ginger turmeric and sumac soda. Photo: Wendy Goodfriend

In another section, there is their house-made farmer cheese, butter from kefir, yogurts and sour creams.

Another unusual find: carrot caramel, which is made from slow cooking carrots for 12 hours, caramelizing them in honey, which they use for carrot cake.

Leaving that fridge, we turned the corner into the main part of the kitchen, where Burns was most excited about a jar of their house-made paprika. While they had been drying and dehydrating their own peppers to make the pungent spice for years, they found that nothing they did could match the flavor of paprika from Szeged, a region of Hungary known to have the best. Especially important is the essential oils found in the peppers from the region.

Jar of house-made paprika. Photo: Wendy Goodfriend

Some years ago, with help from Balla’s mother and step-father, who were visiting, they deseeded pounds of Hungarian peppers, and gave the seeds to Juston and Mindy Enos of Full Table Farm in Yountville, who were already growing food for the restaurant.

Now, they have locally grown paprika made from peppers in Yountville: “It’s better than the Hungarian stuff we were getting,” Burns said.

In addition to the various paprika, we were wowed by the various jars of powders. As anyone who has seen the cookbook knows, these chefs take their powders extremely seriously.

Paprikas and other items in pantry. Photo: Wendy Goodfriend — Various paprikas and other items in pantry. Photo: Wendy Goodfriend

Several pages are devoted to how they make them, with six pages devoted to the allium family alone. The items are usually dehydrated (timing varies, it depends on what the vegetable is and its water content), and then ground into a powder, which is then sprinkled into a recipe to add layers of flavor.

The allium family includes: charred green onion powder, green onion powder, sweet onion powder, smoked onion powder, black garlic powder, and green garlic powder.

They mostly go into soups and stews.

“Onion powder goes in anything,” said Burns. “It’s a natural way to create sweetness, so if you have a dish that needs a layer of sweet but you don’t want to add honey to it, if it has an allium base, onion powder will layer that sweetness into it.”

They also have burnt bread powder and burnt eggplant powder, as “anything we can burn, we burn, as we’re really into that aroma,” said Burns. “We char all kind of stuff.”

Yogurt powder gets added onto a wilted kale dish, “it brings in an acidic lactose aroma, and is mainly there for acidity,” Burns explained, while sauerkraut powder functions like salt, but with a built-in hint of acid, too.

Powders: onion, burnt eggplant, yogurt and more. Photo: Wendy Goodfriend

Other vegetables like mushrooms end up in powdered form as well; parsnip powder is in heavy rotation, due to the fact that the chefs prefer not to use refined sugar in their desserts. Given parsnip’s inherent sweetness, parsnip powder is their go-to to be sprinkled on desserts to add sweetness rather than powdered sugar.

“We try to use as little refined sugar as possible,” said Burns. “We’re not about being anti-sugar necessarily, but it doesn’t have as good flavor, and we like working with things that have great flavor.”

One section is devoted to flowers and herbs, some of which are used in their teas, and some in their food, like elderflower, for example.

Herbs in the Bar Tartine pantry. Photo: Wendy Goodfriend

“We’re not bringing in loose teas at the moment, and we’re seeing if we can get farmers to grow tea and ferment it,” said Burns. “We haven’t formed any good relationships yet with people where we know the source.”

While they try to get almost all their spices grown for them locally, of course they have to rely on a few commodity spices, black pepper and coriander are two.

“We’re trying to get someone to grow a pepper tree, but we’d need a field of them with how much we go through,” Burns joked.

Then there is the sprouting section, where a variety of legumes are sprouting, and nuts are soaked to make nut milks.

Along one wall of the prep area are their multi-gallon plastic fermentation tubs. We saw a melon juice made from water kefir that will eventually be turned into a soda or sauce; kefir cream, which will be turned into butter and used in a sauce; red cabbage kraut and whole green cabbage leaves. We saw a green cabbage kraut with horseradish, and one made from mustard greens. One tub held pickling carrots and radishes, and another held a kraut made from Brussels sprouts.

Fermentation tubs with melon juice and kefir cream, red cabbage kraut and more. Photo: Wendy Goodfriend

They generally allow their kraut to sit at room temperature for over a month, though if they get desperate, they’ll serve it before that. “We let it go for as long as can,” said Burns. “I like it after a month or two.”

Back in another small fridge, we saw jars upon jars of various chile pastes, another condiment they take very seriously.

“Chile pastes are one of our passions,” said Burns. Again, in the cookbook, a section on pepper pastes features sweet, charred, chipotle and Southeast Asian sambal styles.

Peppers are first cooked or smoked and then pureed with salt. After fermenting for over a week at room temperature, they are dried in a dehydrator or low oven for 12 to 16 hours, resulting in a tomato paste-like consistency. Then the paste is pureed, and left to mellow in a refrigerator for at least three months, though it’s even better after six.

While there were jars of preserved lemons and limes on a shelf overhead, we also saw jars of a lime-pickle condiment in the fridge.

A variation of the South Indian achar lime pickles, they preserve limes with spices like fresh turmeric, dill, coriander, caraway, chiles, garlic and lime juice, and leave it to ferment for several months. To make the limes into a condiment, which they serve with their whole grilled eggplant or pureed and rubbed on grilled meats, the preserved limes are steamed and then cooked with onions, garlic, chiles and honey until it resembles a paste. That is then refrigerated for up to six months.

At the very back of the kitchen is the wood-fired oven, where Chad Robertson of Tartine Bakery, fires his famous loaves for the restaurant. If only that smell could be bottled or infused into this web page; the photos will have to do.

Chad Robertson of Tartine Bakery's bread. Photo: Wendy Goodfriend

Up at the bar, we saw a few soju infusions. Bar Tartine does not have a liquor license, but because the Korean spirit soju (made from rice) has less alcohol than traditional spirits, they infuse it themselves to make various cocktails. For example, one is infused with buddha’s hand, a citrus, and another with parsnips.

Cortney Burns at the bar in Bar Tartine. Photo: Wendy Goodfriend

Much of their inspiration comes from earlier projects. With the parsnip soju, Burns said “we had parsnip scraps from juicing it, but the scraps still had a lot of flavor, so we thought, ‘what would happen if we put parsnip in soju?’”

So when asked whether they keep a master list of all of their various kitchen projects at Bar Tartine, Burns laughed.

“Not at all,” she says. “We’re totally not organized, we’re not those people. We’re lucky to get dates written on, we have to remember to put the years.”

Now that they’ve been in business four years, it’s not uncommon for them to find a mysterious jar. Knowing what’s in it is usually easy to figure out, but then they ask “What year did we make this?”

It’s this kind of experimentation that keeps the food at Bar Tartine so innovative.

And if this article has inspired you to get fermenting or powdering, there’s one thing to know before you begin. Many people assume that preserving or fermenting is a great way to use food that is on it’s way out or was not that great to begin with. Big mistake, Burns warns.

“If you don’t start with something delicious, it won’t make it better by fermenting it, so that’s been a good lesson,” she said. “We’ve had to throw away a fair bit. People want to bring us 100 pounds of things, but the first thing we ask is ‘Is it tasty?’”

Vegetables headed for fermentation can be cosmetically challenged, she said, but they must taste as good as their better looking cousins.

And while many of these projects may seem way too daunting as well as unrealistically labor-intensive for the home cook, Burns said that many of them are much easier than they look.

“Buy our book!” Burns said. “The fermentation stuff in there is pretty straightforward. You can do almost all of it in your own kitchen.”

Bar Tartine's facade. Photo: Wendy Goodfriend

Recipe: Pickled Mushrooms

Used with permission from Bar Tartine: Techniques & Recipes (Chronicle Books, November 2014)

We see versions of these pickles in Russian markets and in Italian delis. Both types are equally addictive. We make our version with lots of paprika, which gives it a strong Hungarian accent. The draw of this dish is the combination of the savory garlic-laced paste that coats the outside and the sweet-and-sour, almost-creamy-textured inside of the button mushroom. This pickle is great to have on the table with all kinds of meals and with the Liptauer dip.

Pickled Mushrooms. Photo credit: Chad Robertson

Bar Tartine: Techniques and RecipesBar Tartine: Techniques and Recipes

Powders and Ferments Galore: A Peek Inside Bar Tartine's Project Kitchen