Break the shell of the bael fruit with a hammer into two. It is much like breaking a coconut shell. Scoop out the pulp with a spoon into a large strainer.
Use your fingers to strain the pulp in a bowl. You may need to add some water while doing this process. Take as much time as possible and squeeze out all the pulp which sticks to the seeds too.
Once you have the pulp ready, take it in a blender. Add the rest of the ingredients. I have given 2 cups of water. This makes about 6 glasses of thick smoothie. You can add more water as per your desired consistency.
The jaggery is added only if you do not have a very sweet bael.
Chill in the refrigerator. Pour in glasses when chilled. Garnish with mixed seeds if you have any. Serve bael panna chilled.
You can make this bael panna without the yogurt as well. Then it becomes a bael sherbat.