Vinegar is an ingredient shrouded in vagueness. Unless it’s an authentic bottle of balsamic vinegar, unhelpful labels simply state “red wine,” “white wine,” or “Champagne,” with no further details on a bottle’s ingredients, much less on the grape varieties used to produce it. But a few American producers want consumers to elevate their dishes with varietal vinegars.

Apart from wine, there is one ingredient we do know is in all vinegars: oxygen. Its presence is necessary, as grape juice can only ferment into wine in an anaerobic environment. But in order for wine to sour into vinegar, it requires the alcohol to oxidize into acetaldehyde, which converts to acetic acid. For commercial vinegars, this process is sped up through technology, but artisan producers use a lengthier, more natural process. “Slowing down the fermentation adds flavor layers to the wine vinegar,” says Rodrigo Vargas of American Vinegar Works. After, the vinegar ages in neutral oak barrels for at least a few months. The best producers will bottle from the barrel as needed, which allows the remaining vinegar to mellow even more. If significant time passes, the first and last bottles taken from the barrel might even express different flavor profiles.

To make good vinegar, producers need to start with a complex and structured wine. “Vinegar makers can take wine that didn’t turn out right, but not [spoiled] wine,” says Reginald Smith, owner of Supreme Vinegar and author of “Vinegar, the Eternal Condiment: Uncovering the Science, Business and Sometimes Rollicking Story of Vinegar.” If there aren’t enough flavor components or tannins, the vinegar will end up flat. For a bottling made from red wine, Vargas experimented with Pinot Noir, Cabernet Sauvignon, and Merlot, before deciding on an American Shiraz. “Shiraz is such a big wine that it brings more flavor with it,” he says. “It led to more distinction at the end of the palate.”

According to Smith, wine vinegar didn’t become popular in the U.S. until after Prohibition. Soon after, new technology standardized commercial production, resulting in the bland, nondescript vinegars we see in grocery stores today. Artisanal producers wanted to change that.

Albert Katz of Napa Valley’s Katz Farm was one of the first producers to highlight the grapes he used for vinegar. After spending a few decades in restaurants in both Oakland and Berkeley, Calif., he moved to Napa in the mid-‘90s, hoping to create better ingredients for area chefs.

“I’m trying to use the landscape I live in,” says Katz. That landscape, of course, includes miles upon miles of vineyards. His inspiration for a slightly sweet, late-harvest Sauvignon Blanc bottling was tasting a similar Sauvignon Blanc vinegar in Italy years before. “I envisioned a vinegar with residual sugar like a Sauternes,” he says. He also makes vinegars from Pinot Noir, late-harvest Zinfandel, and late-harvest Viognier, which is sweetened with his own honey.

Katz Farm varietal vinegars
Credit: Katz Farm

Vinegar Has Terroir?

When sourced from local vineyards, vinegar is yet another way to capture a wine region’s terroir and signature grapes. Jay Rostow of Virginia Vinegar Works produces Chardonnay and Cabernet Franc-focused vinegars, and has experimented with Merlot and Cabernet Sauvignon in the past. But wine geeks can nerd out over his Norton vinegar and a current offering made from Petit Manseng ice wine. He describes the former as “leathery and dark,” while the latter displays the aromatic base wine’s tropical flavors. Petit Verdot and Charbourcin show up in his blends for depth and color. There’s also Nebraska’s George Paul Vinegar, which showcases Midwestern varieties like Edelweiss, the lesser-known white wine grape Brianna, and a relatively new red wine hybrid grape, Temparia.

In addition to terroir, varietal vinegar can display the seasonality of a region’s vintage. Often, vinegar makers use whatever surplus grapes are available. That’s why Sarah Conezio and Isaiah Billington of Keepwell Vinegar bottle by variety, and not just as red or white wine. The duo works with a farm on Kent Island in the Chesapeake Bay, and vary their offerings depending on what’s harvested. Keepwell recently bottled vinegar made from Petit Manseng, which expresses a buttery flavor. According to Conezio and Billington, the offering is more honeyed than a previous season’s Viognier bottling. That vintage was a clean and crisp white wine vinegar, with notes of sweet citrus.

Keepwell vinegar varietal vinegars
Credit: Keepwell Vinegar / Instagram.com

Conezio and Billington once headed into the vineyard post-harvest to gather up any extra Cabernet Franc left on the vines. That batch presented a different seasonality issue: noble rot. Unlike with wine, the mold tends to change the aromatics of a vinegar more than the flavor and sweetness. Rostow says noble rot occurred with his 2018 vintage as well. “It gives the final vinegar a fruity fullness of character,” he says. When another wine flaw, brettanomyces, sneaks into a wine, it adds more leathery and earthy flavors to the resulting vinegar.

The surprising range of flavor is all the more reason to seek out varietal vinegars. They present a different expression of a region’s terroir and vintage variations. And just like the best wines, the characteristics of these vinegars are anything but vague.