Duck eggs will last up to 3 weeks in the refrigerator. But, there are some important facts that people don't commonly know about the quality of duck eggs. The fresher the duck eggs the better are the results, the duck eggs are rich, delectable and delicious. I pride myself on shipping extremely fast and fresh.
Duck eggs can be used for any number of cooking methods. But, they must be very fresh under 7 days old to get your best results especially for poaching, frying, or hard boiling. Older then 7 days they are still excellent in baking and recipes, but the whites are a little rubbery.
Closer to 21 days old, you need to be mindful that some duck eggs could be turning bad. First each egg should be checked by cracking open in a small clear glass bowl. The whites should be a clear white and no odor. If it has started to turn bad, you will see the white is cloudy or slightly yellow in color, or it might have an off smell, meaning the odor is not like a fresh egg.
Some duck eggs do last longer then 21 days, but they should be checked over with care.
I have tripled my duck flock and expect most of them to be laying daily by November/December 2009. This would be the only way I can ship large amounts of duck eggs and insure to the buyer that they are fresh.
Be aware that many shippers of duck eggs do not ship fresh duck eggs. I have acquired repeat dedicated duck egg customers because according to them, I am the only one that ships duck eggs very fresh, and sad to say, in the past other shippers have sent them half bad duck eggs.
I hope this informaion helps you!