Placing a spoon in my hand, Simone Caselli says, “Are you sure you’ve tasted real balsamic vinegar?” He doesn’t wait for an answer, but lifts the spherical bottle of balsamic just enough to slowly release three thick drops—the result of years of labor and patience—onto the spoon.

In the fertile Italian region of Emilia Romagna, among beloved products like Parmigiano Reggiano cheese and Lambrusco wine, the world’s premiere balsamic vinegar is produced. The traditional vinegar is a far cry from what is commonly called balsamic; an imposter made of grape must and caramel coloring. Here, there are some 300 producers of traditional balsamic vinegar (A.B.T.M., Aceto Balsamico Tradizionale di Modena), with the majority located in the suburbs of Modena. This peaceful city—with arched porticos lining the streets and a serious reputation for food—has earned even more attention recently, after chef Massimo Bottura’s Osteria Francescana was named World’s Best Restaurant in 2016.

These days, everything is so fast. But for the best balsamic, you can’t be in a hurry.

From the outside, Acetaia Caselli doesn’t look any different from surrounding homes on the quiet, tree-lined street. But behind closed doors, the Caselli family has been tending balsamic for three generations. “It all started with my grandfather, Piretto,” Caselli tells me as we climb steep stairs to the attic. On the second step, the pungent, sweet smell of vinegar fills the humid air. “Our attics have no insulation,” he says. “We want very cold temperatures in winter, and warm and moist conditions in the summer.” The Po River valley is famous for this temperature fluctuation that creates ideal conditions for producing balsamic vinegar.

“Vinegar begins in the vineyard,” Caselli says. “We don’t buy grapes, but have our own organic vineyard.” (His balsamic is made from 30 percent white Trebbiano grapes and 70 percent red Lambrusco grapes.) After harvest, the grape juice—without skin or seeds—is cooked in the open air for 24 hours until it reduces by half. The cooked “must” is stored in the cellar for two months, and then moved to large oak or chestnut mother barrels in the attic where it ages for one year.

At the top of the stairs, I see the depth of the attic with several series of increasingly smaller sized barrels, called a battery. The key to traditional balsamic is a combination of evaporation and aging, with the mother barrel “feeding” each battery’s largest barrel after evaporation. In the winter, Simone performs the annual ritual of pouring vinegar down the line (from the largest barrel toward the smallest), replenishing the volume of each, and creating a super concentrated product in the smallest barrel.

We leave the attic and descend into an informal tasting room. Traditional balsamic must age for at least 12 years or 25 years to achieve the extravecchio label. “When tasting traditional balsamic vinegar, you are looking for a balance between sweet and sour, strong but smooth,” Caselli says. From the few drops on my spoon, with no competing flavors, I can taste the purity of the balsamic—its acidity and sweetness hit simultaneously.

Simone opens a bottle of Lambrusco and we settle in for lunch. We try balsamic on an omelette, over homemade bread and salami, and poured over a rich pasta with bacon and cheese. He releases a single droplet of the 25-year-old balsamic onto hunks of Parmigiano-Reggiano. For dessert, a drizzle over cheesecake with fig jam.

Above our heads, 600 barrels hold balsamic vinegar in various stages of production. “These days, everything is so fast,” Simone says. “But for the best balsamic, you can’t be in a hurry.”

What to look for when you buy balsamic: Only one kind of bottle—a 100 ml (3.3oz) spherical bottle with a narrow neck for the cork—can be used by all producers for traditional balsamic vinegar. For the 12 year, the color of the cap is red. For the 25 year, the color is gold and extravecchio will be written on the label.

Plan a visit to Acetaia Caselli: Email Simone at info@acetaiacaselli.it to arrange a visit to his home for a tour, tasting, and lunch, from €6 ($7) to €35 ($40).