Walking through Zialena Winery is a study in old-world wines made with modernity in mind. The 7,000-square-foot, custom-built winery completed in 2016 sits among 120 acres of vines owned and tended by the Mazzoni family since 1931.

But the family's grape-growing roots go even deeper than that. Giuseppe Mazzoni, who settled in the Alexander Valley in 1897, began making wine alongside other immigrants. Later, he and his two sons, Fred and Jim, continued to make jug wine ("The Mazzoni Special") in what has become an iconic sight along a stretch of Highway 101 running through Sonoma County - a weathered old barn advertising "Dr. Pierce's Medical Discovery."

In 1931, younger son Jim purchased the 120-acre ranch that Zialena Winery sits on today, building a home on the outskirts of the property. Though the ramshackle barn-winery closed in 1977 and the family's winemaking fizzled to a halt when eldest son Fred died, Jim's son, Mike, established Mazzoni Vineyards, a sole-proprietorship company, around that same time, expanding the family's grape-growing business.

Today, Mazzoni Vineyards is home to 70 acres of Cabernet Sauvignon, 20 acres of Zinfandel (nine of which are the "Mazzoni clone"), 6 acres of Sangiovese, and a recently planted 3 acres of Sauvignon Blanc and Chardonnay. Mazzoni Vineyards sells about 95% of its estate fruit to big-name wineries such as Jordan Vineyard & Winery, Jackson Family Wines and Alexander Valley Vineyards.

It wasn't until 2011 that the Mazzoni family returned to winemaking. Lisa Mazzoni, fourth-generation owner and general manager of Zialena Winery, said her brother Mark made wine as a side project early in his winemaking career. After nearly 20 years of professional winemaking experience at various wineries, Mark was ready to make wines bearing a Mazzoni label - but he knew there was more to starting a business than just making wines.

"My brother said to me, 'I want to make wine under a family label, and I'm not doing it unless you do it with me,'" said Lisa Mazzoni, who has a background in hospitality and business management. "At the end of the day, we're going to run the vineyards anyway, and we thought 'Why not try to do something with it? Why not put our generation's mark on the family business?'" she said.

Cementing the winery's foundation
The first two Zialena vintages, released in 2014 and 2015, were created at a custom-crush facility. "Those facilities have a protocol, a barrel regimen, and you sign up for all of that at the beginning and they execute on your behalf," Lisa Mazzoni said, "You don't have any kind of flexibility."

It was that need for flexibility, the ability to experiment with their own wine grapes, that provided the impetus for the two Mazzonis to design and construct their own winemaking facility.

Mazzoni said her brother had worked at enough wineries to know what kind of space he wanted to create. The two sat down with architect Dave Siegert of Osborn Siegert Architecture in Santa Rosa, Calif., to sketch the layout and functionality of their ideal winery and tasting room.

The two buildings, which sit side-by-side in the center of Mazzoni Vineyards, are what Lisa Mazzoni calls "low-profile" modern architectural design. "We're along the valley floor, so we wanted a lower-set building to complement that," said Mazzoni, who added she didn't want a grandiose or "castle-like" structure to disrupt her scenic vineyard surroundings. She said she also wanted to play on the juxtaposition between her family's old-world winemaking and the modernity she and her brother bring to the family's story. "We're rooted in our family legacy but we're not re-creating the wines of the 1900s," she said.

The north- and south-facing walls of the tasting room each feature floor-to-ceiling glass doors, created by Progress Glass in San Francisco and installed by the Mazzonis' general contractor, Wright Contracting in Santa Rosa. The 3 acres of land directly surrounding the tasting room are currently decorated with little flags, indicating the recently planted vines of a future field blend of Zinfandel, Carignane and Mourvèdre, which they'll use for future vintages of Capella - a red wine blend created each year as a nod to the family's jug wine history.

The Mazzonis' pride and joy rests inside the winery - a state-of-the-art facility that includes a barrel room, a wine laboratory and the foundation of the building: 10 open-top concrete fermentation tanks.

The tanks were custom-built by Sonoma Cast Stone in Petaluma, Calif., and include the Zialena insignia, a ravioli stamp, on each tank. "When my Zia Lena (for whom the winery is named) passed away, my mom ended up with her brass ravioli stamp," Lisa Mazzoni said. She took that stamp to designer Aly Anderson at Notion Creative in Sonoma and has incorporated it into all of the winery's branding.

Sonoma Cast Stone worked alongside the architectural team to figure out how best to design the winery around those concrete tanks. Indeed, the fermentation tanks were the first thing put in place at Zialena Winery, with everything else constructed around them.

"They're actually structurally attached to the building," Lisa Mazzoni said. "When they were cast, they had to put bolt holes in certain places in order to attach it to the rest of the building."

It was Mark Mazzoni's decision to focus the winery around concrete fermentation. According to Lisa Mazzoni, her brother had attended a trade show showcasing the effects of concrete on wine: It's more porous, allowing more oxygen during initial fermentation; provides a richer mouthfeel; and imparts a kind of briny backbone to the flavor profile. "He was fascinated by the science behind it and the overall quality of the wines produced," she said.

Each tank holds 3 tons of grapes and includes internal glycol tubing to control temperature, with heating coils at the base and cooling coils farther up top. The tubing is hooked up to TankNet computer displays on a side wall and monitored by assistant winemaker Jesse Giacomelli.

Giacomelli said the tanks can warm up to about 110° F and cool down to below freezing. "One of the best things about concrete is that it's so well insulated," Giacomelli said. "With stainless you can get heat spikes, but here that'll never happen. I don't think we ever get above 85° F."

However, the drawback, Giacomelli said, is the cleaning process. "You can't steam-clean or pressure-wash concrete tanks because they're so delicate," he said. Giacomelli gets in each tank with his intern and, using a food-grade detergent and scrub brush, scrubs each of the tanks by hand, neutralizes them with an acidic solution and rinses each with cold water. "It's a laborious, three-step process," he said.

Focused small-batch winemaking
With just a 3,000-case annual production, the winemaking team is a small one, composed of Mark Mazzoni, Giacomelli and one intern. During harvest, Zialena doesn't hire harvest hands directly, but instead sources about 20 to 24 laborers through Munselle Vineyards.

With only red grape varieties currently at maturity in the estate vineyards, harvest season lasts from about the first week of September through the last week of October, according to Giacomelli.

All grapes are hand-harvested. "All of our fermentations are whole-berry, and mechanical harvesting breaks up the berries quite a bit," Giacomelli said. "As soon as those berries break, the juice is exposed to oxygen and a wild microbial population, both good and bad, thus beginning the fermentation process. We'd rather maintain control over that aspect."

Grapes are collected into half-ton macro¬bins, then forklifted onto a slow-moving escalator and sorted by hand as they move into the Bucher Vaslin Delta Oscyllis destemmer - a destemmer that swings the cage, applying a gentle, gradual force to separate stems and berries. The grapes are then gravity-fed back onto a sorting table for another round of manual sorting. "We're actually hand-sorting twice, which is a really different way of making wine," Lisa Mazzoni said. "We process our fruit a lot slower, about 1 ton per half-hour."

While the Cabernet grapes are stripped of stems completely, Zinfandel lots contain about 5% whole-cluster inclusion, "to include a bit of backbone," Giacomelli said.

Grapes are dumped directly from the sorter into the concrete tanks to undergo initial fermentation. Giacomelli said he and Mark Mazzoni use a combination of native and inoculated yeast - D254 for Cabernet and Clos for Zinfandel. "We want to move toward entirely native," Giacomelli said. "We have an open screen, vineyard air and yeast flowing in all the time, so ideally we'd have our own 'house yeast.'"

But it can be a little risky to do 100% native fermentation straight-away, he said, so for the past two vintages he and Mark Mazzoni inoculated half the wines with commercial yeast and let half ferment on their own. "Things went really well last year, so this year we'll probably try to do seven or eight batches of native," Giacomelli said.

The red wines ferment for about two to four weeks in the concrete tanks with twice daily punchdowns, pumpovers or rack and returns. Once initial fermentation is complete, Mazzoni and Giacomelli pump the free-run wine directly into oak barrels, with each tank filling about five to six barrels.

Zialena's wines are aged in a mixture of new and neutral French oak barrels, using varying toast levels from Artisan, Ermitage, Taransaud and Radoux cooperages. "Ninety-nine percent of our barrels are neutral because we don't want to mask the grapes," Giacomelli said. "We like to work with the same coopers, but experiment with the different toast levels and forests ... to build up 'the spice rack' and have those blending tools."

Pomace from the fermentation tanks goes into the Bucher Vaslin JLB Automated Basket Press. "This basket press is so incredibly gentle, the pressed juices almost taste like free-run," Giacomelli said. Those pressed juices are barreled and aged separately for potential blending.

Red wine ages 20 to 24 months at Zialena, with regular stirring once every two weeks. Once the wines are ready, Mazzoni and Giacomelli conduct blending trials in the winery's lab facility - where they also test other data during the winemaking process such as pH, acidity, alcohol, sulfur dioxide and volatile acidity.

Final blends are filtered into the Westec utility tank to homogenize, then put back into barrel to settle for three to four months before bottling.

All red wines are bottled unfiltered and unfined using a mobile bottling service. The winemaking team is currently in transition between bottling companies. "Since our first wines back in 2012, this'll be our fourth or fifth bottler. Quality bottlers are hard to find," Lisa Mazzoni said.

"And it's hard to find someone to want to work with us," Giacomelli added. "We're such a small production facility, most bottlers want to work with wineries doing 30,000 cases not 3."

Barrel-fermented white wines
Because the 3 acres planted to Chardonnay and Sauvignon Blanc won't bear fruit for a few more years, the Mazzonis purchase white grapes. "It's varied over the years, but this will be our third harvest getting Sauvignon Blanc from the Redwood Ranch in Alexander Valley," Lisa Mazzoni said. "We'll also be getting Chardonnay from them this year for the first time."

White grapes are harvested by hand, then fed directly into the winery's new Puleo 24-hectoliter membrane press. After, the juice goes into the utility tank to allow any extremely heavy lees to settle. Chardonnay is racked off the lees into French oak puncheons (25% new) and left to ferment in the cold (60° F) barrel room with once-daily stirring. "Initial fermentation lasts about 50 to 60 days, just because it's so cold," Giacomelli said. "We may pull it back a bit, but because of that (long fermentation) I was able to stir every day for two months and really build up the mouthfeel."

Secondary, malolactic fermentation (MLF) proceeds naturally, "unless the pH is too low," Giacomelli said. "Last year I had a few barrels that wouldn't go through MLF on their own, so I used B7 Direct ML culture from Laffort." Once the Chardonnay has completed MLF, it's racked a few weeks later and left to age for about 16 months. White wines are sterile-filtered, using 0.45 µm filters, before bottling.

Giacomelli explained that the winemaking process for Sauvignon Blanc is similar, except they maintain a reductive environment by adding dry ice in the press, thus limiting the escape of volatile aromas. Pressed juices are 100% barrel-fermented in 60-gallon neutral French oak, and the wine is bottled just six months post-harvest.

A lone barrel of 2017 Sauvignon Blanc sits on an Oxo Line Monobloc rotating rack. Giacomelli said this barrel contained Sauvignon Blanc that has been undergoing MLF for the past eight months, with just twice-monthly rotations to maintain a reductive environment.

"What Mark wants to do is have this barrel stay here forever," Giacomelli said. "Next year, he'll take 25% of this barrel and blend it in with the 2018 Sauvignon Blanc, then fill this barrel back up with some of the 2018 vintage." He plans to repeat this process with each vintage, creating a "mother batch" of Sauvignon Blanc and adding another piece to the Mazzoni family legacy.