Gently place your duck eggs in a medium-sized pot, taking care not to crack the shells. Add enough cool water to cover the eggs.
Bring the water to a rolling boil. As soon as the water is boiling, turn off the heat (or remove from heat, if using an electric stove), and cover with a lid.
Set a timer for the amount of time listed below, depending on how you like your duck eggs:For really runny eggs: 4 minutesFor jammy eggs: 5 minutesFor soft eggs: 7 minutesFor medium-hard eggs, where the yolk is still softer but is pretty much fully cooked: 8 minutesFor hard boiled duck eggs: 11 minutes
Once the timer goes off, remove the eggs with a spoon and immediately and place them into an ice bath for a few minutes. Peel, rinse with cool water to remove any shell bits, and enjoy!
Store unpeeled hard-boiled cooked eggs in a sealed container in the fridge for up to 5 days. I have not stored jammy eggs in the fridge, so I can't give you recommendations for those.
Notes
Keep in mind that the exact cook time will depend on a ton of factors, such as: the size of your eggs, the starting temperature of your eggs and your cold water, the amount of water in the pot, the shape of the pot, and the time it takes for your water to boil, the efficiency of your lid and how much heat it seals in.You can always remove 1 egg, cool it and peel it immediately, then remove the others a minute later if that one was done.If you like your eggs cooked a very specific way, I recommend approaching this with the most nerdy and scientific way possible: MEASURE the amount of water you add and its temperature, and write that down alone with the egg size, number of eggs, and cook times so you can replicate it when you find the right combination.