The dark color in Tirunelveli-style halwa comes from caramelizing the wheat milk and sugar mixture over a long period, typically several hours, allowing the Maillard reaction to occur.
The rich, dark hue of authentic Tirunelveli halwa isn't achieved through artificial coloring. It's a result of a slow and patient cooking process. Here's a breakdown:
Wheat Milk Extraction: The process begins with extracting milk from sprouted wheat. This wheat milk forms the base of the halwa.
Mixing with Sugar: The wheat milk is then combined with a generous amount of sugar. The ratio is crucial for both sweetness and color development.
Slow Cooking: This is the most important step. The mixture is cooked over low to medium heat for an extended period, often several hours. Constant stirring is essential to prevent burning and ensure even caramelization.
Maillard Reaction: As the mixture cooks, the Maillard reaction takes place. This is a chemical reaction between amino acids and reducing sugars that occurs upon heating. It's responsible for the browning and the development of complex flavors.
Ghee Addition: Ghee (clarified butter) is added in intervals during the cooking process. The ghee not only enriches the flavor but also aids in the caramelization process and gives the halwa a glossy finish.
Patience is Key: The longer you cook the halwa, the darker and richer the color will become. The color transformation is a gradual process, so don't rush it.
Use a heavy-bottomed pan to prevent the halwa from sticking and burning. This will ensure even heat distribution and prevent scorching, which can lead to a bitter taste and uneven color.