Over medium heat in a large stock pot, bring the whole milk almost up to a boil. This will take about a half an hour. Make sure to constantly stir the milk so it doesn't burn in the botom of the pot.
While the milk is cooking, line a collander in a large bowl with cheese cloth.
At the 30 minute mark, stir in the lemon juice. You will notice in 30-60 seconds the milk curdling. Turn off the heat.
Pour the milk into the collander. Let it cool.
Once the milk has cooled, start squeezing out any liquid.
Place another bowl filled with water on top of the twisted cheese cloth. This will weigh down the cheese and force out more moisture. Let this sit for an hour.
Take the cheese out of the cheese cloth. At this point, the paneer is firm, but still has some moisture left in it. It will kind of feel like a firmer cream cheese.
Place the paneer in a bowl or container uncovered in the refrigerator over night. This will help dry out the cheese even more.
Your paneer will be ready the next day for use.