Preparing the Spiced Milk and Cream Infusion: Begin by pouring the whole milk and heavy cream into a heavy-bottomed saucepan. Add in the cinnamon stick, star anise, green cardamom pods, whole cloves, allspice berries, black peppercorns, and fresh ginger slices. Place the saucepan over medium-low heat. Gently warm the mixture, stirring occasionally to prevent sticking, until it is hot but not boiling—this should take about 5 to 10 minutes. Once warmed, remove the pan from the heat and cover it loosely. Allow the spices to steep in the warm milk and cream for about 45 minutes. This slow infusion draws out the deep, aromatic flavors essential to the chai profile.
Infusing the Tea and Sweetening: After the initial steeping, add the black tea bags directly to the spiced milk and cream mixture along with half of the sugar. Return the pan to low heat and warm gently for 2 to 3 minutes—again, be careful not to boil. This process releases the robust flavors and tannins from the tea leaves. Once warmed, remove the pan from the heat and allow the tea to steep for an additional 10 minutes. You will notice the liquid darkening to a rich amber color, signaling the depth of flavor has developed.
Preparing the Egg Yolks and Sugar Mixture: While the tea is steeping, combine the egg yolks and the remaining sugar in a medium-sized bowl. Using a whisk, beat the mixture vigorously until it turns pale, thick, and slightly glossy. This step is crucial for incorporating air and creating a smooth custard texture. The sugar helps stabilize the eggs and adds sweetness.
Tempering the Eggs: Before combining the eggs with the warm milk base, taste the infused liquid. If you desire a stronger chai spice punch, sprinkle in a small amount of ground masala chai spice and stir well. Now, to avoid cooking the eggs too quickly, slowly add a few tablespoons of the warm milk mixture into the egg yolks while continuously whisking. Repeat this gradual addition two or three times, allowing the eggs to warm evenly and safely without curdling.
Cooking the Custard Base: Once the egg yolk mixture is tempered, pour it back into the saucepan with the remaining spiced milk and cream. Remove the tea bags at this stage to prevent bitterness. Place the saucepan over medium-low heat and stir constantly with a wooden spoon or heatproof spatula. The goal is to gently heat the mixture until it thickens slightly, which usually occurs around 170°F (76°C). Do not let the mixture boil, as this will cause the custard to split. You will notice the texture becoming creamier and coating the back of the spoon lightly.
Straining and Cooling the Custard: When the custard reaches the right thickness, immediately remove it from the heat. Pour the mixture through a fine mesh strainer into a clean bowl to remove all the whole spices, ginger, and any cooked egg bits. This step ensures a smooth, silky ice cream base without any gritty or chewy pieces. Allow the strained custard to cool to room temperature, then cover tightly and refrigerate for at least several hours or preferably overnight. Chilling the custard thoroughly improves the flavor melding and results in a better texture when churned.
Churning the Ice Cream: Once the custard is well chilled, prepare your ice cream maker according to its instructions. Pour the custard base into the machine and churn until it reaches a soft-serve consistency. This process typically takes 20-30 minutes but will vary depending on your equipment.
Adding the Final Touches and Freezing: During the last few minutes of churning, add finely chopped crystallized ginger for a burst of sweet, spicy texture that complements the chai flavors beautifully. Mix thoroughly to distribute the ginger evenly. Transfer the ice cream into a freezer-safe container and smooth the surface. Cover and freeze for several hours, or until firm, before serving.
