As calves should not get killed in Hinduist India, people use heat (and acid for “paneer” cheese) instead of rennet, to get both cow and water buffalo milk to curdle in a cheese-like product: “khoa”. As the milk is gently cooked at 80°C during a long period of time, it gets a subtle sweetness obtained through the “Maillard reaction” between milk sugars (lactose) and proteins (casein).
Unlike cheese, khoa is used as the base for a wide variety of Indian sweets; but like cheese, it is durable. When refined, it acquires a green tint, and is then called “hariyali” (green khoa).
One could argue that one of the flaws of this technique, is that all the milk’s water is lost in the air, but the obtained product is even richer than regular curd. Khoa producers don’t get the whey by-product that can be difficult to valuate: in the US, it used to be thrown in rivers, causing devastating eutrophisation — it is now dried to obtain bodybuilding supplement with high profit (10L of milk = 1kg of cheese + 600g of dry whey costing up to 25€). In Europe, it is often spread on land and fed to animals, but can be recycled as ricotta, or more surprisingly sodas, like “Rivella”.
- A sort of caramelization