Why should custard be eaten within 3 days of opening?

There is no specific recommendation to consume custard within 3 days of opening. The actual shelf life of custard depends on the type of custard and storage conditions.

Here are some general guidelines:

- Fresh homemade custard (without preservatives): Homemade custard should be consumed within 2-3 days when refrigerated.

- Store-bought custard (with preservatives): Unopened store-bought custard can typically last up to the date printed on the packaging. Once opened, it usually stays fresh for 5-7 days when refrigerated.

- Frozen custard: Custard that has been frozen can last for several months, though its quality may gradually diminish over time.

Custard, like any dairy product, can deteriorate and spoil if not stored properly. It is always a good practice to check for signs of spoilage such as an unpleasant smell, off-taste, or changes in texture before consuming custard. If in doubt, discard it to ensure safety.