Barfi (Reduced-Milk Fudge)

Variations

• Kaju katli: ground cashews in place of khoya. It is the best-selling kind in India and it is far quicker, since no milk has to be reduced — but half of this page disappears with it.
• Coconut barfi: desiccated coconut alongside the khoya. The fibre physically gets in the way of the crystals, which gives a softer bite.
• Pista, chocolate and besan barfi: ground pistachio, cocoa, or roasted gram flour. The besan version needs its own roasting stage first.
• Vark (edible silver leaf): what Indian sweet shops lay on top. It contributes nothing to the flavour and the sweet is the same without it.
• The exact opposite operation to rasgulla. That one breaks milk with acid and lifts the curd out; this throws nothing away and drives the water off over hours. Same milk, opposite direction — and the rasmalai named in that page's variations is steeped in exactly this khoya.
• Diwali and festivals: barfi is in almost every box of mithai.

Tips

• It is the reverse of every other sugar confection here. Lokum uses invert sugar to stop crystals growing, nougat uses glucose and honey for the same job, and tanghulu drives sugar to 155°C and sets it as crystal-free glass. Barfi wants crystals. It wants them very small, and what decides their size is how you stir it as it cools.
• So the stirring rule reverses twice inside one recipe. While the syrup boils, do not stir at all — a spoon drags crystals off the pan wall and they seed it. Once it is off the heat, keep stirring — you are making a great many tiny seeds at once so no large crystal gets the room to grow. Lokum also reverses its own rule mid-recipe, for a different reason.
• Reducing milk is not concentration, it is change. Dairy and heat mentions evaporated milk in one clause as "already heat-concentrated, its proteins stabilised", and moves on. Two hours does more than that: lactose and milk protein react with each other (browning and the Maillard reaction) and the colour and smell change completely. Khoya is not strong milk, it is a different ingredient.
• Wide pan, heavy base. In a tall narrow pot there is no surface for the water to leave from and two hours becomes three; in a thin pan the base scorches first.
• Low-fat milk will not do. The fat is what gets between the crystals and keeps it tender. Reduce the same weight without it and you get something hard and coarse.
• Score it warm. The same reason as the caramel on Dobos torte, with a much more generous window here — about ten minutes rather than thirty seconds.
• Not in the fridge. It hardens and the surface takes up moisture. Room temperature is right for the reason yōkan keeps at room temperature: the sugar is doing the preserving.