Bring a pot with 6 cups of water to a low simmer. Add in the drained bird's nest and jujubes.
Keep the heat on low - you don't want a hard, rolling boil (which would break the delicate bird's nest). Aim for the smallest bubbles possible.
Cook for 30 minutes - 2 hours. The timing really depends on the quality of the bird's nest that you have. For Golden Nest's products, it only took 30 minutes of cooking to get a gelatinous texture. If you over-cook the bird's nest, it will become gummy and break apart, ruining the very expensive delicacy!
Taste the bird's nest - it should be soft, gelatinous, slippery-like.
Add in 4 medium chunks of rock sugar. You can turn off the heat and just let the sugar slowly dissolve. Taste and add additional sugar if you'd like. The flavor should be delicately sweet.