An etrog is a very interesting fruit. You never really hear of it except for during Sukkot, and even then nobody eats it; we just shake it. It doesn’t help that they’re really expensive, and not that easy to eat.
This was my first experience cutting into an etrog. It’s a citrus fruit similar to a lemon, but you can’t squeeze the juices out. I guess you can use the outside like you would lemon zest, but it would be much harder, since the surface isn’t very smooth.
Jewish superstition connects etrog jelly to pregnancy and fertility. I have heard that it eases labor pains, helps a woman get pregnant, and can be eaten any time during pregnancy for health and luck.