Strain juice to remove seeds and pulp if using lemon or lime.
Add milk to a heavy bottomed pot and place on low to low-medium heat.
Stir often to prevent burning. (Add seasonings if desired, see step #2 in the section above).
Once the milk starts to boil, turn off the heat.
Stir in the acid (stir in one direction to form larger curds). The milk should curdle almost immediately.
Strain the curds using a cheesecloth and strainer (or colander). Save the whey for other recipes or to make paneer in the future.
Rinse the curds to remove any acidic taste.
Squeeze the curds tightly to remove any excess liquid.
Shape the paneer in the cheesecloth and place heavy weights on it to compress the cheese.
Refrigerate for at least four hours (although leaving overnight makes a firmer paneer)
Cut, cube, and serve.