Whenever I make paneer, I am amazed at the smooth slab that seems to magically emerge from what was just a vessel of milk.

Chemically, I can understand sugar dissolving in water and then reverting to crystals as the water boils away. But to think that all the crumbly proteins and fats that make up paneer were suspended in the smooth milk, seems incredible.

The truth is, milk is nothing like salt or sugar. It is a far more complex chemical marvel. And that is why one can do amazing things with it, once it is truly understood.

Milk contains various proteins, with casein being the most abundant. Proteins are essentially long chains of amino acids that are larger than typical molecules but still invisible to the naked eye. In milk, casein proteins are organised as micelles, which resemble tightly wound balls of yarn.

By default, casein micelles repel each other, but are attracted to the water molecule. Thus they remain more or less evenly distributed in a solution.

Add acid, and one gets a trail of loose hydrogen ions in the liquid too. These ions react with the micelles, upending the delicate balance. The more acid one adds, the greater the turbulence. Add a small amount of hydrogen ions, and the milk proteins form soft gels such as yoghurt. As more acid is added, the micelles steadily lose their charge, until at some point they arrive at a net charge of zero. At this point, they no longer interact well with water and do not repel each other. The proteins now start to coalesce, pushing out the water, and forming paneer.

Fat plays a key role in quality. The hardest paneer comes from skimmed milk.

For the smoothest, spongiest paneer, use buffalo milk rather than cow’s milk, because it has larger fat globules and micelles, and more calcium and phosphorus, allowing for a denser and more even network of bonds. Even a 1:1 blend of buffalo and cow’s milk will yield distinctly spongier slab.

The situation is reversed when it comes to mithai. Cow’s milk is the milk of choice for chenna, the soft paneer used to make sweets such as rasgullas and chum chum. Cow’s milk creates a soft, smooth chenna that is vastly superior to the coarse, greasy, chewy one yielded by buffalo milk.

The process for both paneer and chenna is similar. Boil the milk, let it cool slightly, then add an acid (such as a little vinegar or a squeeze of lime or of any citrus fruit). Once the cheese coagulates, strain the mixture. For chenna, use as is at this stage. For paneer, keep the cheese pressed for about an hour, to shape it.

The temperature of the milk and the levels of acidity will determine the texture now. If both are high, casein micelles clump up, resulting in a dryer, chewier paneer. For paneer tikkas, which need to offer resistance when bitten, a higher temperature (about 85 degrees Celsius, when the acid is added) is preferable. For a soft malai paneer, keep the milk at about 70 degrees Celsius and acidity levels low (typically two to four teaspoons of lime juice per litre).

A common complaint about store-bought paneer is that it is often too hard. This is partly because manufacturers deliberately dry it out a little. Reducing moisture content by even 5% can extend shelf life. If you then fry it or use it in an acidic (say, tomato-based) sauce, the proteins tighten and it hardens further. To avoid this, soak it in warm water or a 3% brine solution for a few minutes and let it absorb some moisture before adding it to a dish.

It really is that easy to use paneer well, or to make it. I’d love to hear your hacks, or know how your next paneer dish turns out.

(To reach Swetha Sivakumar with questions or feedback, email upgrademyfood@gmail.com)

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