Buttermilk Panna Cotta

I’ve always preferred panna cotta made with equal parts buttermilk and heavy cream. The buttermilk’s tangy edge adds depth and moderates the richness of the heavy cream, and the heavy cream plays an important practical role: It can be heated past 150 degrees—the temperature at which I have found that gelatin reliably dissolves and flavorings can be infused into it—without curdling. Curdling happens when a protein in dairy called casein clumps when heated. But heavy cream has enough fat to dilute the casein molecules, preventing clumps. Since lean buttermilk can curdle at temperatures as low as 110 degrees, I like to heat the cream, sugar, and bloomed gelatin and then wait for the mixture to cool before stirring in the buttermilk.

Now, about gelatin, the key—and somewhat temperamental—ingredient in panna cotta. I started by “blooming” it, meaning I hydrated it in cold water.

There are two methods for blooming powdered gelatin. The most common is to sprinkle it in an even layer on a dish of cold water, where it slowly hydrates. For my panna cotta, I found that the other approach, called “bulking,” was even easier. It’s done by whisking the gelatin together with sugar (or another dry ingredient) before mixing it into water—or, in this case, cream, which contains plenty of water. The sugar helps separate the gelatin granules so that they remain independent while they disperse throughout the watery liquid and can hydrate thoroughly and evenly.

Next, I heated the mixture to dissolve the gelatin. As the mixture cooled, it set into a solid gel.

To serve eight, I thickened 4 cups of dairy with 2 teaspoons of gelatin. This was just the right amount to produce a satiny‑smooth, lush dessert that managed to be ethereal and creamy at the same time. I whisked the gelatin together with sugar (½ cup for modest sweetness) and a pinch of salt to enhance flavor, added 2 cups of cold cream, and let the mixture sit for 5 minutes. Next, I heated the mixture until it reached 150 degrees and the gelatin had dissolved. Finally, I let the cream-sugar-gelatin combination cool to about 105 degrees before stirring in 2 cups of buttermilk. Now it was ready to be portioned and chilled.

With my basic recipe complete, I capitalized on one of the many advantages of panna cotta: It takes beautifully to flavorings. I made one version infused with an aromatic vanilla bean and then garnished with a drizzle of honey and fresh raspberries and blackberries—an elegant take on berries and cream. Then, for something different yet still luxurious, I steeped grapefruit zest in the cream and garnished the panna cotta with crunchy caramel-coated almonds. But my hands-down favorite was Thai basil–infused panna cotta topped with strawberries that I had macerated with sugar and black pepper.