Put the whole milk (8 1/2 cups) to boil on medium heat and stir in the meanwhile, so it does not burn. As soon as it starts boiling, add the freshly squeezed lemon juice (2 tbsp) and stir well. The milk will react to the juice and the product you will eventually get is curd. In order to get it, keep boiling until it separates from the milk and then leave aside for about 10 minutes. What you should do next is squeeze the curd through a cheesecloth and rinse it well under running water. This last procedure will remove the lemon juice. 

Wrap the curd with the cheesecloth again and let it stay like this for an hour (or until you see it is ready) in order for it to drain well from the water. Once it is done, move it to a bowl and start making knead-like movements, so it mixes well until perfectly smooth. Next, add the flour (5 tbsp) and mix well again. 

When you are done with the curd mixture, pour the water (4 cups) and add the granulated sugar (2 cups) to a (preferably) pressure cooker. Put it on the heat and wait for the mixture to boil.

In the meantime, make smooth balls of the curd-flour mixture (as shown in the photo above) and add them to the pressure cooker. As soon as you are ready with this, put the lid on. After he first whistling of the cooker, boil for another 10 minutes. 

Let the rosogollas cool completely before touching them. They must have doubled the initial size and will be quite delicate while burning hot.

Once they have cooled, pour the rose water or the saffran syrup (made from a few saffran threads and warm water) over the rosogollas. 

Cool the rasgullas for a few hours before serving.