1. Use a sealing machine to seal the egg yolk crisps and store them in a cool and dry place. The storage time can be appropriately extended, but it is best to eat them within a week.

2. If you cannot use preservatives at home, then buy some desiccant and put it in the box of egg yolk cakes. Keeping the egg yolk cake dry can extend the shelf life.

3. Putting it in the refrigerator can extend the time, but it is best to eat it within a month. If you want to give it away, you can use an insulated box with dry ice. The dry ice will not melt so quickly, so you can just take it out and finish it in time.

4. If you want to store it for a long time, store it in the freezer and bake it before eating. It tastes the same as the freshly made one, but the crispiness is slightly worse.