Bring the milk to boil and switch off the flame.
Add the acid to milk and continue stirring it. It will start separating paneer from milk and a light green color liquid will separate from it. This liquid is called whey.
The whole process will take about 30 seconds. Once you notice that large chunks of paneer are separated and a clear green water is formed, add ice and cool it down.
Using a muslin cloth or sieve drain the excess water in another pan. Add about one liter water to paneer and wash with hands. Drain again.
Now the paneer you have obtained should be drained off excess water.
tie it in the muslin cloth and keep under some weight for 2 hours. It will squeeze out the excess moisture. Your paneer is ready. You can store in fridge for up to 3 days.