Robert Renzoni Winemaker Tests Ancient Winemaking For 2023 Harvest

TEMECULA, CA —Winery owner Robert Renzoni and winemaker Olivia Bue of Robert Renzoni Vineyards are looking to the past to plan for the future of their winemaking.

Bue recently showed Patch around the vineyard and inside the barrel room where they are testing ancient winemaking practices of fermenting inside large, Roman-style amphorae jars, one of terra cotta clay and one of cement. When the experiment is complete and a full tasting compares the results, they will better understand the impact of the different fermentations and the impacts the new containers have on the wines, she said.

The jars are expected to soften the tannins and increase the texture of the wines they produce, she said. It is a winemaking practice that is one of the oldest in the craft, according to Bue.

Though they are not the only winery in the valley to use the amphorae jars, they are intent on perfecting the process, she said.

For 2023, Renzoni Vineyards is testing a single varietal grape—a locally grown Vermentino— to determine how the differing jars enhance or detract from the wine. A third batch of the same varietal will be processed in stainless steel, as per usual, she said.

Later, they will sample the wines as they ferment and determine which process works best. The expected result will be a light white, think Sauvignon Blancs or Pinot Grigios, in flavor.

According to Grapevine Magazine, clay amphorae will yield wine with flavors somewhere in the middle (of stainless steel and oak).

"The porous clay vessels allow oxygen inside, helping soften tannins and flavors," Bue predicted. Also, since clay is a neutral material, oxygen enables wines to develop without imparting additional flavors, she said.

Wine benefits from fermenting and aging in amphora due to the unique properties of the vessel. While oak barrels are porous, allowing exposure to oxygen and flavor from the wood's tannins, stainless steel tanks create wine in an oxygen-free environment. Wine made in stainless tanks is returned fresh and crisp, according to the article.

Clay, on the other hand, is an excellent thermal conductor, which releases the heat from fermentation, leaving little to no need for temperature control. Inside, the wine evolves slowly, preserving the fresh and fruity aromas, the magazine said. The vessels can last for decades and can create competitive wines of any variety, according to the article.

"Assuming the wine turns out, I would love to bottle separately and then showcase the flavors," Bue said.

After much study, how the wine turns out will be answered as the hypothesis is implemented.

"Do we ferment in them? Do we post-age in the amphorae vs. stainless steel? This is an experiment to educate us on how the clay softens tannins or changes the structure," she said.

Meanwhile, the rest of the harvest was crushed and prepped to ferment and ultimately rest in toasted oak barrels selected by Bue and Renzoni earlier in the year.

Building a sustainable winery...

Robert Renzoni Winery is also incorporating more sustainable gardening methods than ever to stay on the cutting edge as the most sustainable winery in the Temecula Valley. Their harvest occurs 100% in Temecula Valley, both on the property and private vineyards contracted with Renzoni.

After the harvest, casks of Sangiovese, Petite Syrah, Chardonnay, and other blends signature to the vineyard await the perfect combination of art, science, and patience in anticipation of a 2023 label.

Still, winery managers and winemakers are constantly looking forward to what's next and planning years in advance.

In the vineyard, new Montepulciano vines have replaced a stretch of 28-year-old Cabernet Sauvignon.

"This will be a 100% varietal that we label and will be a unique offering in the future," Bue said. She figures over 10,000 bottles of the Montepulciano when the vines are ready to produce in three to four years.

The addition of the vines is part of Renzoni's long-term plan for the property, she said.

"We're focusing on becoming a fully sustainable winery in the area," she said. "We're doing whatever we can to enrich our soil with hearty chicken manure." The nutrients are expected to work further down into the soil during this winter's expected El Nino rains, further washing the effects of drought from the soil.

"The rain flushes salts out of the soil and enables the nutrients to work their way down to the roots," she said. "We all need our vitamins, and our winery workers have enriched the vineyard with some of the highest quality chicken fertilizer."

Bue loves the hands-on work of making wine, including the desire to make each vintage better than the last.

"My favorite thing is being able to work really hard on something that takes three to four years in the process," she said. "Ultimately, sitting down at the end and sharing the fruits of our labor with family and friends is what this is all about."