Bogurar Doi is a distinctive sweetened yogurt from the Bogra district in northern Bangladesh. While sweet yogurt (mishti doi) is common across Bengal, Bogurar Doi has three unique characteristics: (1) it has a firm, almost pudding-like consistency that can be sliced with a knife; (2) it has a characteristic tan-brown color (not white or pale brown); and (3) it has a smoky, caramelized flavor unlike any other sweet yogurt. The secret lies in the traditional preparation method using "kansha" (bronze) pots and slow-baking in a clay oven.

The traditional recipe dates back to the early 19th century, invented by a confectioner named Siraj Uddin in the village of Sherpur, Bogra. It uses full-fat buffalo milk, which is boiled in a bronze pot for hours until reduced by 40-50%. Jaggery (palm sugar) is added, along with a touch of burnt sugar for color. The mixture is then poured into unglazed clay pots (handis), which are sealed with dough and placed in a clay oven ("tandoor") with low, smoldering charcoal. The slow, indirect heat for 6-8 hours creates a gentle caramelization and a smoky infusion. The pots are then left to ferment overnight.

The result is a dense, rich yogurt that is intensely sweet but balanced by a slight tanginess. Unlike commercial yogurts that use gelatin or cornstarch for thickness, Bogurar Doi achieves its texture purely through milk reduction and fermentation. It is traditionally eaten as a dessert after meals, often topped with ground pistachios or almonds. In 2019, Bogurar Doi was granted GI status, officially recognizing it as a product of Bangladesh.

The GI tag has helped protect the product from imitations — many sweet shops in Dhaka sell a pale, runny yogurt labeled "Bogra-style doi," which is not authentic. The government has also established a "Bogurar Doi Quality Control Laboratory" to test for adulteration (e.g., added starch or synthetic caramel color). However, the industry faces challenges: buffalo milk is expensive, and the traditional bronze pots are being replaced by stainless steel, which changes the flavor. Efforts are underway to revive buffalo farming and to train new generations in the art of slow-baking in clay ovens. With proper support, Bogurar Doi could become Bangladesh's first GI-certified dessert exported globally.