The etrog is a medium-sized citrus fruit, with a color, scent and taste similar to a lemon. It is used in the waving rituals of the festival of Sukkot, where it is said to represent the heart (because of its shape), and also said to represent the ideal kind of Jews, who have both knowledge of Torah and good deeds (because it has both a pleasant scent and a pleasant taste). -Excerpted from Judaism 101
I have always loved lemons. When I was nine I planted a couple seeds after making lemonade. I watched one of them sprout and grow up into a sturdy, fragrant lemon tree that accompanied me through life. Several years ago, for a variety of reasons, I passed the tree along to one of my sisters.
Recently, while visiting the New York Botanical Garden, my son told me he missed the lemon tree and suggested we plant an etrog tree to replace it. Since his 10th birthday was approaching, this struck me as a perfect gift idea. I went home that day, did some googling, and found Zaide Reuven's Esrog Farm. I ordered three.

Most of the 20 or so seeds we found had already germinated.

The second etrog had many seeds as well, but they seemed to be either past their prime or diseased.
The thick white rind did not want to separate from the peel.

The peels soaked in water for two days to release some bitterness. The water was left a pale shade of yellow, fragrant, and (I had to taste it) extremely bitter!
After boiling and changing out the water four times to remove more of the bitterness, I simmered the peels in a sugar water mixture for about 90 minutes.
Once peels became translucent, my son scooped them out onto a tray of sugar. We tossed them around to get full sugary coverage, and now they sit and wait to be eaten...